MASARYK UNIVERSITY
FACULTY OF SCIENCE
Department of Experimental Biology
Section of Animal Physiology and Immunology
Novel molecular mechanisms of cancer
cell death regulation
Habilitation thesis
Brno 2018 RNDr. Alena Hyršlová Vaculová, Ph.D.
© Alena Hyršlová Vaculová, Masaryk University, 2018
It is a great pleasure for me to express my appreciation to all people who made this
habilitation thesis possible, my former supervisors and teachers, my colleagues and friends for
their support, collaboration, inspiration and fruitful discussions.
I would like to thank the former and current heads of the Department of Cytokinetics,
Prof. RNDr. Alois Kozubík, CSc., Prof. RNDr. Jiřina Hofmanová, CSc., Prof. RNDr. Jan
Vondráček, Ph.D., Mgr. Karel Souček, Ph.D. and all my former and current colleagues from
the Institute of Biophysics, Czech Academy of Sciences, and the Department of Experimental
Biology, Faculty of Science, Masaryk University in Brno, and other colleagues from
cooperating institutions in the Czech Republic and abroad, especially from Karolinska Institutet
in Stockholm. I would also like to thank to all my former and current students for their
enthusiasm and teamwork.
My warm thanks belong to my family for their continuous support, encouragement,
patience and love, especially to my husband Pavel and our son Jan, my parents, grandmother,
sisters, and my husband´s parents.
Table of contents
Abstract ……………………………………………………………………………...….……. 1
Abstrakt …………………………………………………………………………...………….. 2
1. Introduction – apoptosis......................................................................................................3
1.1. Apoptosis and cancer....................................................................................................... 3
1.2. Apoptotic pathways ......................................................................................................... 3
2. TRAIL.................................................................................................................................6
2.1. TRAIL – basic characteristics ......................................................................................... 6
2.2. TRAIL-induced apoptotic signalling............................................................................... 7
2.2.1. Mechanisms of cell resistance to TRAIL-induced apoptosis............................... 9
2.2.2. Sensitization to TRAIL-induced apoptosis – combined therapy ....................... 11
2.2.2.1. Platinum drug-mediated sensitization to TRAIL-induced apoptosis........................................... 13
2.2.2.2. 5-fluorouracil-mediated modulation of TRAIL-DR pathways.................................................... 15
2.2.2.3. Doxorubicin and etoposide as effective sensitizers to TRAIL-induced apoptosis ...................... 17
2.2.2.4. Epigenetic drugs in modulation of TRAIL-induced apoptotic signalling ................................... 17
2.2.2.5. Docosahexaenoic acid in modulation of TRAIL-induced cell death........................................... 18
2.2.2.6. Potential non-selective toxicity of TRAIL-based combination therapy...................................... 19
2.3. TRAIL-induced non-apoptotic signalling ..................................................................... 19
2.3.1. Necroptosis......................................................................................................... 19
2.3.2. Non-cell death signalling ................................................................................... 20
2.3.2.1. NF-B pathway........................................................................................................................... 21
2.3.2.2. ERK pathway.............................................................................................................................. 22
2.3.2.3. PI3K/Akt pathway....................................................................................................................... 22
2.4. TRAIL-induced apoptotic versus non-apoptotic signalling .......................................... 23
2.4.1. Pleiotropic function of DR4/5 during carcinogenesis........................................ 23
2.4.2. DR4/5-specific signalling in cancer ................................................................... 25
2.4.3. DR4/5 compartmentalization in TRAIL signalling............................................ 25
3. Summary and future perspectives.....................................................................................28
4. References.........................................................................................................................29
5. Supplement list..................................................................................................................55
6. Supplements 1-19
Hyršlová Vaculová 2018
1
Abstract
An efficient and selective induction of cancer cell death is a main goal of many
therapeutic approaches, and identification of the suitable candidates that are capable to do so,
especially by triggering apoptosis, represents a continuous need in oncology. Activation of the
apoptotic signalling via TRAIL death receptors (DRs) is an attractive, tumour-specific and
biologically relevant approach that can be exploited in the future cancer therapy. However,
numerous cancer cells develop the resistance to apoptotic effects of this cytokine and/or activate
undesired alternative non-apoptotic signalling resulting in enhancement of their malignant
behaviour. The balance between the two types of signalling is crucial in determination of final
cancer cell fate and outcome of TRAIL-based therapy, and can be efficiently modulated by
different classes of therapeutically relevant compounds.
In the work presented within this thesis, the apoptosis-sensitizing abilities of several
classes of conventionally used or recently introduced chemotherapeutic drugs such as cisplatin,
LA-12, 5-fluorouracil (5-FU), doxorubicin or etoposide, epigenetic drugs – decitabine or
valproic acid (VPA), and dietary compounds like docosahexaenoic acid (DHA) were
investigated in order to boost the cytotoxic potential of TRAIL/DR signalling in cancer cells.
Several molecular determinants of their stimulating effects on TRAIL/DR apoptotic signalling
pathways were newly demonstrated, especially at the level of death-inducing signalling
complex (DISC), mitochondria and caspases. In addition, the research included in this thesis
also uncovered novel details about the role of kinase-mediated non-apoptotic signalling in
regulation of cancer cell sensitivity to the cytotoxic effects of TRAIL, with a particular attention
to MAPK/ERK and PI3K/Akt. These results contribute to the better understanding of the
complexity of TRAIL-induced signalling and targeting molecular bases of the frequent
resistance of tumours to TRAIL-based therapy, which are essential prerequisites for its
potentially successful clinical application. In the light of the most recent knowledge on this
topic, the theses presents the research findings of the author and her colleagues summarized in
19 publications (18 original articles and 1 review), which demonstrate the proposed efficient
strategies for triggering apoptosis in human cancer cells by the above-mentioned therapeutically
interesting drugs or their combinations, and the molecular mechanisms involved.
Hyršlová Vaculová 2018
2
Abstrakt
Účinná a selektivní indukce smrti nádorových buněk je hlavním cílem řady současných
terapeutických strategií a identifikace vhodných kandidátů, které mohou zajistit eliminaci
těchto buněk zejména prostřednictvím apoptózy, je velkou výzvou v onkologii. Aktivace
apoptózy přes receptory smrti (DR) pro TRAIL představuje atraktivní, selektivní a biologicky
významný přístup využitelný v budoucí protinádorové terapii. U některých nádorových buněk
však dochází k vývoji rezistence k apoptotickým účinkům tohoto cytokinu a/nebo spuštění
nežádoucích alternativních “neapoptotických” signálních drah vedoucích spíše k posílení jejich
maligního chování. Rovnováha mezi uvedenými dvěma typy signálování je proto naprosto
klíčová pro určení finálního osudu nádorové buňky, rozhoduje o efektivitě terapie využívající
TRAIL a může být účinně modulována prostřednictvím různých typů terapeuticky zajímavých
látek.
Ve výzkumu, který je součástí předkládané habilitační práce, byla studována schopnost
různých konvenčně používaných i nových chemoterapeutických látek - cisplatiny, LA-12, 5fluorouracilu
(5-FU), doxorubicinu a etoposidu, epigeneticky působících látek – decitabinu a
kyseliny valproové (VPA) a některých složek potravy jako je kyselina dokosahexaenová
(DHA) stimulovat cytotoxické signálování spuštěné u nádorových buněk přes DR pro TRAIL.
Bylo popsáno několik nových mechanismů posílení apoptózy indukované přes DR, zejména na
úrovni signálního komplexu DISC, mitochondrií a kaspáz. V rámci výzkumu obsaženého v této
práci byly rovněž představeny nové poznatky o úloze „neapoptotického“ signálování
zprostředkovaného kinázami v regulaci citlivosti nádorových buněk k cytotoxickým účinkům
TRAILu, především s ohledem na zapojení MAPK/ERK a PI3K/Akt. Získané výsledky
přispěly k hlubšímu pochopení komplexity signálních drah aktivovaných přes DR pro TRAIL
a molekulární podstaty rezistence některých nádorů k terapii založené na působení TRAILu,
což je nutným předpokladem jeho potenciálně úspěšné klinické aplikace. V této habilitační
práci jsou ve světle recentních poznatků v dané problematice prezentovány výsledky výzkumné
práce autorky a jejích kolegů, které jsou součástí 19 přiložených publikací (18 originálních
článků a 1 review) popisujících účinné strategie pro spuštění apoptózy nádorových buněk
s využitím uvedených látek a jejich kombinací, včetně zapojených molekulárních mechanismů.
Hyršlová Vaculová 2018
3
1. Introduction – apoptosis
Great numbers of the cells in a human organism die throughout its life, and these death
events are often essential for its survival as a whole. So far, a variety of cell death types and
subroutines have been discovered and classified, but the main focus has been paid on apoptosis,
as this form of cell death seems to be the most frequent, the best understood, and the most
significant. Apoptosis (from a Greek word that means “falling off of leaves from tree”)
represents an active process responsible for elimination of old, damaged, dangerous or
unnecessary cells via stimulation of evolutionary conserved and genetically controlled
molecular pathways that mediate cellular demise. A general concept of apoptosis was first
proposed by Kerr and colleagues (Kerr et al, 1972), but the importance and resulting
consequences of these findings were underestimated for many years. Subsequently, it has
become increasingly evident that apoptosis is implicated in numerous biological processes
starting from an early embryonal development to late aging, is crucial for maintenance of
homeostasis of a multicellular organism, and often involved in pathogenesis of various human
diseases (Favaloro et al, 2012; Lockshin & Zakeri, 2007). With its crucial discoveries and their
practical applications, research on apoptosis has become one of the hottest fields in biomedical
sciences, associated with rapidly increasing numbers of exciting new findings published in
journals focused on this topic each year. Importantly, a great proportion of “apoptosis-related
papers” is focused on the regulation of this process in cancer cells (Melino & Vaux, 2010).
This theses presents the selection of 19 publications (18 original research articles and 1
review), which summarize the results of our work that contribute with the novel findings to the
cell death research field, being especially focused on the investigation of efficient strategies for
triggering apoptosis in human cancer cells by selected therapeutically interesting drugs or their
combinations, and the molecular mechanisms involved. Within the individual chapters, our
results are described in the context of the most recent knowledge on this topic, together with
the suggested consequences and future perspectives.
1.1. Apoptosis and cancer
Cancer is a disease characterized by an abnormal accumulation of cells due to an
imbalance between their division and death. Evasion of apoptosis has been proposed as an
important mechanism implicated in malignant transformation, and one of the hallmarks of
cancer (Fig. 1) (Hanahan & Weinberg, 2000; Hanahan & Weinberg, 2011). Furthermore, blocks
in apoptosis can contribute to inherent or acquired resistance to a variety of anticancer agents.
Thus, apoptosis is implicated in both pathogenesis and treatment of cancer, and involves
complex regulation at the different levels inside the cells (Rufini & Melino, 2011; Zhivotovsky
& Orrenius, 2006). Targeting apoptotic machinery and specific components of apoptotic
pathways is considered as an attractive anticancer strategy, with numerous molecules currently
under investigation for their promising therapeutic potential (Fox & MacFarlane, 2016; Pfeffer
& Singh, 2018).
1.2. Apoptotic pathways
Apoptosis is manifested by a cellular shrinkage, plasma membrane blebbing,
condensation of nuclear chromatin and fragmentation of DNA, followed by separation of the
cell fragments into so-called apoptotic bodies, which are phagocytosed and degraded within
phagolysosomes, without triggering an inflammatory response (Elmore, 2007; Taylor et al,
2008). Generally, the cells undergo apoptosis via two major molecular signalling pathways, the
extrinsic (death receptor-mediated) and the intrinsic (mitochondrial) (Fig. 2) (Calvino
Hyršlová Vaculová 2018
4
Fernandez & Parra Cid, 2010; Fulda & Debatin, 2006). The extrinsic pathway is initiated by
extracellular death inducers such as specific ligands of the tumour necrosis factor (TNF) family
that bind to their cognate cell surface death receptors (DRs). This results in the recruitment of
Fas-associated death domain (FADD) protein, formation of the death-inducing signalling
complex (DISC), and activation of initiator caspase-8 and -10 (Dickens et al, 2012). This step
can be effectively modulated by the cellular FLICE (FADD-like IL-1-converting enzyme)inhibitory
protein (cFLIP), which is frequently deregulated in cancer cells (Hughes et al, 2016;
Shirley & Micheau, 2013). The active caspase-8 can directly cleave effector caspase-3 and -7,
and enable further propagation of the cell death (Tummers & Green, 2017).
Fig. 1: The hallmarks of cancer (Hanahann & Weinberg, 2011).
The mitochondrial pathway of apoptosis is triggered by intrinsic signals involving
growth factor deprivation, DNA damage induced by irradiation or chemicals, oxidative or
oncogenic stress (Galluzzi et al, 2012). These death signals are sensed and propagated by the
Bcl-2 family of proteins, the main regulators of the mitochondrial apoptotic machinery (Adams
& Cory, 2018; Czabotar et al, 2014; Kale et al, 2018), which can be categorized into three main
groups: The first group comprises pro-apoptotic BH3-only proteins characterized by the
presence of a single BH (Bcl-2 homology) domain in the molecule (Bid, Bim, Puma, Noxa,
Bad, Hrk, Bmf, Bik). They monitor numerous cellular processes and transmit the stress signals
to the mitochondria, and their cooperation with the multi-domain Bcl-2 family partners at the
level of these organelles is critical for triggering of the intrinsic apoptotic pathway (Delbridge
& Strasser, 2015). Mimicking their pro-apoptotic action using the small molecule drugs called
“BH3 mimetics” offers a promising strategy to promote apoptosis in some resistant tumours
(Sarosiek & Letai, 2016). The second group is represented by the pro-apoptotic effectors with
three BH domains (Bax, Bak, Bok), capable to form pores in mitochondrial outer membrane
(MOM) and thus promote its permeabilization (MOMP) (Chipuk & Green, 2008; Wei et al,
2001). The third group consists of anti-apoptotic members with four BH domains (Bcl-2, BclxL,
Mcl-1, Bcl-w, A1/Bfl-1), which protect the cells from death by sequestering their proapoptotic
partners within the Bcl-2 family (Delbridge & Strasser, 2015). Overexpression of
these proteins may often be used by cancer cells as a strategy to develop apoptosis resistance
(Campbell & Tait, 2018).
Hyršlová Vaculová 2018
5
The character of mutual interactions and the ratio of pro- to anti-apoptotic Bcl-2 family
members represent a “rheostat” that determines the cell susceptibility to apoptosis induced via
the intrinsic pathway, which is used to kill cancer cells by most chemotherapeutic and targeted
therapies. Importantly, understanding of these interactions enables scientists to assess the cell
“priming for death”, i.e. how close is the cell to the threshold of apoptosis (Sarosiek et al, 2013).
Based on these findings, dynamic BH3 profiling, a sophisticated functional approach to study
the mitochondrial readiness to undergo apoptosis and to predict the cell chemotherapeutic
response was developed (Del Gaizo Moore & Letai, 2013; Letai, 2015; Letai, 2017). By
employing specific synthetic BH3 peptides in drug-treated cells, this assay helps to determine
the dependency of particular tumour on individual anti-apoptotic Bcl-2 family proteins and its
vulnerability to trigger MOMP following the treatment. The MOMP and subsequent release of
pro-apoptotic mediators such as cytochrome c from mitochondrial intermembrane space into
the cytosol is often considered as the point of irreversible commitment to cell death.
Cytochrome c, in cooperation with the adaptor protein apoptotic protease activating factor 1
(Apaf1) and in the presence of ATP, participates in the formation of apoptosome, a molecular
complex necessary for the activation of caspase-9 (Liu et al, 1996; Zou et al, 1997).
The intrinsic and extrinsic pathways converge on a “common pathway” resulting in the
activation of potent effector caspases (-3, -6, -7), which are involved in disintegration of
numerous structurally and functionally important cellular substrates, and apoptosis execution
(Inoue et al, 2009; Olsson & Zhivotovsky, 2011; Timmer & Salvesen, 2007). The caspases are
recognized as crucial players in apoptosis, and determination of their activation and detection
of caspase substrate cleavage are considered as useful biochemical markers of apoptosis. The
apoptosis detection methods based on evaluation of these parameters both in vitro and in vivo
applications were described in detail by numerous authors and also in our previous work,
together with experimental protocols, advantages and disadvantages of these techniques, and
background information (Vaculova & Zhivotovsky, 2008) (Supplement 1).
Fig. 2: The extrinsic and intrinsic apoptotic pathways – main characteristics
(Calvino-Fernández & Parra Cid, 2010).
Hyršlová Vaculová 2018
6
Caspase activity can be blocked by endogenous cellular inhibitor of apoptosis (cIAP)
proteins (e.g. X-linked inhibitor of apoptosis protein - XIAP, cIAP1/2, survivin) that do so
either through direct binding or by targeting caspases for ubiquitin-mediated degradation
(Mohamed et al, 2017). The cIAPs are often overexpressed in multiple human cancers, being
responsible for promoting tumour progression and contributing to treatment failure (Fulda,
2014). The cIAP-mediated inhibition of caspases can be countered by endogenous second
mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with
low pI (Smac/DIABLO), which is released into the cytoplasm following MOMP (Du et al,
2000; Martinez-Ruiz et al, 2008; Verhagen et al, 2000). Thus, the synthetic small molecule
inhibitors mimicking the pro-apoptotic action of this protein, called “Smac mimetics”, represent
an important class of targeted drugs for cancer treatment (Fulda, 2017).
Importantly, diverse molecular connections exist between intrinsic and extrinsic
apoptotic pathways, which can substantially affect the intensity of apoptotic response and a
final cell fate. Understanding the complexity of these molecular interactions will enable the
design of more efficient therapeutic approaches for particular tumour types. Although apoptosis
represents a well-recognized mechanism for elimination of cancer cells exposed to conventional
chemotherapy, the research focused on the molecular basis of the selective apoptosis-targeted
therapies has been developed more recently. This approach mainly aims to: (i) induce or restore
pro-apoptotic pathways by specific death ligands, monoclonal antibodies or fusion proteins
(e.g. those targeted to DRs) (Fox & MacFarlane, 2016; Fulda, 2015), or (ii) prevent the action
of anti-apoptotic molecules (e.g. cFLIP, cIAP or some Bcl-2 family proteins) that are
upregulated in tumours by specific small molecule inhibitors like BH3, Smac mimetics and
others (Fulda et al, 2010; Gibson & Davids, 2015; Humphreys et al, 2018; Timucin et al, 2018).
Moreover, it has become increasingly evident that the simultaneous application of at least two
different approaches will help to maximize the therapeutic outcome, while minimizing the
undesired treatment-related toxicities in normal cells.
In our work, a particular attention has been paid to the investigation of the anticancer
effects of an interesting cytokine and death ligand with unique ability to selectively induce
cancer cell apoptosis, without being toxic to normal tissues, the phenomenon that can be
promisingly exploited in cancer therapy. Within the following chapters, the general as well as
specific aspects of TNF-related apoptosis-inducing ligand (TRAIL)-induced signalling and
novel mechanisms responsible for its modulation are described, and the results of our work
related to this topic and their significance are introduced and discussed.
2.TRAIL
2.1. TRAIL – basic characteristics
TRAIL was discovered independently by two groups, based on its sequence homology
with TNF and CD95L (Pitti et al, 1996; Wiley et al, 1995). The human 20 kb gene coding for
TRAIL is located on chromosome 3, and comprises five exons and four introns. The TRAIL is
expressed as a type II transmembrane protein consisting of 281 amino acids, which can undergo
proteolytic cleavage to release the region of 114-281 amino acids, the soluble ligand. The
endogenous TRAIL can be expressed on the membrane of natural killer (NK) cells,
macrophages, T-cells and dendritic cells, being involved in immune defence mechanisms by
killing virus-infected or cancer cells. The biological activity of TRAIL can be enhanced by its
trimerization (Wiley et al, 1995).
Hyršlová Vaculová 2018
7
2.2. TRAIL-induced apoptotic signalling
TRAIL interacts with two DRs, namely DR4 (TRAIL-R1, TNFRSF10A, CD261) (Pan
et al, 1997a) and DR5 (TRAIL-R2, TNFRSF10B, Killer, CD262) (MacFarlane et al, 1997;
Screaton et al, 1997; Walczak et al, 1997), the type I transmembrane proteins with characteristic
death domains in their cytoplasmic regions (Fig. 3) (Lemke et al, 2014a). Binding of
membrane-bound or soluble TRAIL to DR4/5 induces receptor oligomerization and triggers
extrinsic apoptotic pathway associated with FADD-dependent formation of DISC and initiator
caspase-8/-10 activation. The activity of DISC can also be affected by other proteins recruited
to this complex such as Cul3, PP2AC or others (Jin et al, 2009; Shirley et al, 2011; Xu et al,
2013; Xu et al, 2014). In so-called type I cells, the amount of caspase-8 activated at the DISC
is sufficient for efficient propagation of apoptotic signal and activation of effector caspases,
while type II cells rely on the Bid-mediated amplification of apoptotic signal via mitochondrial
pathway (Fig. 4) (Ozoren & El-Deiry, 2002; Schneider-Brachert et al, 2013). In addition, the
TRAIL-induced cytotoxicity may also require the lysosomal permeabilization and the release
of non-caspase proteases into the cytoplasm, which is the case in the type L cells (Akazawa et
al, 2009).
Fig. 3: Structure of TRAIL receptors – schematic picture (Lemke & Walczak, 2014).
The unique ability of TRAIL to act as a selective inducer of cancer cell apoptosis both
in vitro and in vivo was originally demonstrated by two independent groups who reported its
cytotoxic effects in various human cancer cell lines and also showed tumour xenograft
regression in mice or non-human primates treated with recombinant variants of human TRAIL
(Ashkenazi et al, 1999; Walczak et al, 1999). An additional benefit of TRAIL is that it can
initiate cancer cell apoptosis independently of their p53 status (Ravi et al, 2004). These
discoveries provoked an enormous interest in exploiting TRAIL for cancer therapy and deeper
investigation of various preparations of TRAIL. Early on, several alarming publications
reported on TRAIL toxicity to normal hepatocytes, an undesired side effect that could disqualify
its application in clinic (Jo et al, 2000; Lawrence et al, 2001). However, later studies clarified
that the hepatotoxicity was an artefact caused only by particular tagged forms of TRAIL and
could be avoided by the selection of the more safe available variants (Ganten et al, 2006).
Based on these findings, various TRAIL-receptor targeting agonists (TRAs) were
approved for clinical applications – human recombinant soluble untagged TRAIL
(dulanermin/Apo2L.0/AMG-951) and several DR4 (mapatumumab) and DR5 (drozitumumab,
lexatumumab, conatumumab, tigatuzumab, LBY-135, DS-8273a) agonistic antibodies (Naoum
Hyršlová Vaculová 2018
8
et al, 2017). Unfortunately, despite numerous promising preclinical results obtained with
dulanermin, clinical trials failed to demonstrate any significant anticancer activity (Dubuisson
& Micheau, 2017; von Karstedt et al, 2017). These disappointing results are most likely caused
by its short plasma half-life and rapid clearance from the circulation, a limited ability to cluster
TRAIL DRs, and simultaneous engagement of DcRs. Compared to dulanermin, DR4/5-specific
agonistic antibodies are characterized by higher stability, longer half-life, and no interference
with TRAIL DcRs. However, similarly as in case of dulanermin, they did not exert sufficient
therapeutic activity or improve overall patient survival (von Karstedt et al, 2017). The main
factors responsible for the clinical failure of these antibodies seem to be their bivalent mode,
still insufficient ability to induce higher-order DR clustering, and additional need for more
efficient crosslinking. Taken together, although all these “first generation” TRAs are safe and
well tolerated in patients, so far they have failed to achieve a significant therapeutic effect in
randomized-controlled clinical trials.
Fig. 4: TRAIL-induced signalling in type I and II cells, basic scheme (Schneider & Brachert, 2013).
In the light of the recent insights on TRAIL signalling, novel “next generation” TRAs
with improved agonistic capacities, stability and tumour-specific delivery have been developed.
The enhanced stability of TRAIL has been achieved by non-covalent addition of N-terminal
tags such as Flag epitope, leucine/isoleucine zipper motifs and tenascin-C (TNC)
oligomerization domain, permutation of the ligand (circularly permutated TRAIL) or covalent
link to molecules that help to increase its pharmacokinetic and pharmacodynamic properties
(Stuckey & Shah, 2013; von Karstedt et al, 2017). For an enhancement of tumour delivery,
passive or active targeting approaches have been utilized. Passive targeting is often based on
enhanced permeation and retention (EPR) effect, and employs TRAIL coupled with
nanoparticles, either encapsulated inside or attached to the surface of the nanoparticle,
mimicking the physiological membrane-bound protein. Various TRAIL-bearing nanoparticles
containing human serum albumin, polyethylene glycol, liposomes or other molecules have been
engineered and further examined (de Miguel et al, 2016; Guimaraes et al, 2018). Active
targeting takes advantage of using TRAIL fused with antibody fragments or peptides that
Hyršlová Vaculová 2018
9
specifically recognize antigens that are highly expressed by cancer cells or cells of tumour
stroma, thus enabling to preferentially hit the desired target (de Miguel et al, 2016). Next,
various types of monoclonal DR4/5-specific antibodies and derivatives functionalized to
nanoparticles or linkers that enable to increase their valency, bioavailability and efficacy are
being developed (Dubuisson & Micheau, 2017).
Importantly, even the best-designed TRAs may be ineffective in cancer cells that bear
serious defects in apoptotic signalling pathways triggered via DR4/5. Thus, in addition to the
above-mentioned potential causes of the failure of TRA-based therapy, the intrinsic or acquired
resistance can be the crucial factor responsible for the insufficient cytotoxic response observed
in TRA-treated tumours. Although TRAIL resistance in cancer cells has been investigated and
demonstrated at multiple points in TRAIL apoptotic pathway, as described in the next chapter,
the precise molecular mechanisms involved need detailed clarification. It also remains to be
understood whether the single factor or the combination of several of them may be responsible
for TRAIL resistance in particular cell types and if different cancers develop TRAIL resistance
through similar or distinct mechanisms. Deeper understanding of these issues will enable the
correct identification of reliable biomarker or biomarker set for precise assessment of tumour
response to TRA-based therapy, which is still far from being complete (von Karstedt et al,
2017). So far, no sufficient predictive biomarkers have been successfully employed in the
clinical trials in order to identify specific group(s) of patients with preferential sensitivity to
TRA-based therapy (Ralff & El-Deiry, 2018).
2.2.1. Mechanisms of cell resistance to TRAIL-induced apoptosis
The presence of DR4/5 at the cell surface is an essential but not sufficient precondition
for the initiation of apoptotic TRAIL signalling, and the low surface level or unavailability of
functional receptors may correlate with decreased sensitivity of cancer cells to TRAIL. It can
be caused by specific genetic or epigenetic changes in cancer cells such as gene deletions
(Ozoren et al, 2000), loss-of-function mutations (Bin et al, 2007; McDonald et al, 2001; Pai et
al, 1998) or promoter hypermethylation (Hopkins-Donaldson et al, 2003; Horak et al, 2005).
The surface DR4/5 level can also be modulated by their deficient transport to plasma membrane
(Jin et al, 2004) or their constitutive endocytosis from the cell surface (Zhang & Zhang, 2008).
Although being indispensable for the triggering of TRAIL-induced apoptosis, the
presence/amount of DR4/5 at the cell surface is unlikely to serve as an independent biomarker
of TRAIL sensitivity that would enable to predict the patient responsiveness to treatment with
TRAs. In addition to the changes in the total surface DR4/5 level, their distribution in the plasma
membrane within the lipid rafts, membrane micro-domains enriched in cholesterol and
sphingolipids, can influence the receptor clustering and the DISC assembly in cancer cells
(Marconi et al, 2013; Ouyang et al, 2011). These events may be affected by posttranslational
modifications of DR4 or DR5 such as S-palmitoylation (Rossin et al, 2009), N-glycosylation
(Dufour et al, 2017) or O-glycosylation (Wagner et al, 2007). Interestingly, high expression of
O-glycosylation enzyme N-acetylgalactosaminyltransferase 14 (GALNT14) was suggested as
a signature for cancer cell sensitivity to TRAIL, but these findings need further validation
(Wagner et al, 2007).
In addition to DR4/5, TRAIL can also bind two membrane-bound “decoy” receptors –
DcR1 (TRAIL-R3, TNFRSF10C, CD263) (Degli-Esposti et al, 1997b; Pan et al, 1997b;
Sheridan et al, 1997) and DcR2 (TRAIL-R4, TNFRSF10D, CD264) (Degli-Esposti et al,
1997a; Marsters et al, 1997; Pan et al, 1998). These receptors are unable to induce apoptosis
due to a complete (DcR1) or partial (DcR2) lack of the death domain. However, they can
compete with DR4/5 for ligand binding, thus lowering the amount of TRAIL available for
initiation of apoptotic signalling. Moreover, DcR2 can inhibit TRAIL-induced apoptosis by
forming inactive complexes with DR5 (Merino et al, 2006) or stimulating anti-apoptotic
Hyršlová Vaculová 2018
10
signalling mediated by NF-B (Degli-Esposti et al, 1997a) or PKB/Akt (Lalaoui et al, 2011).
While the ratio between TRAIL DRs and DcRs was suggested to affect the ability of the cells
to trigger TRAIL-induced apoptosis (Sheridan et al, 1997), subsequent studies did not confirm
the clear correlation between the high/low DcRs level and resistance/sensitivity to TRAILinduced
cytotoxicity (Griffith et al, 1999). Thus, it seems that the amount of the surface DcRs
level cannot be considered as a sufficient predictor of the cell responsiveness to the cytotoxic
effects of TRAIL. Finally, TRAIL can also interact with osteoprotegerin (OPG, TRAIL-R5), a
soluble decoy receptor involved in regulation of osteoclastogenesis (Emery et al, 1998; Simonet
et al, 1997). However, as OPG binds TRAIL with lower affinity compared to other TRAIL-Rs,
its role in inhibition of TRAIL-induced apoptosis in cancer cells is less apparent.
TRAIL resistance can also be caused by decreased/lost expression or impaired function
of the crucial initiator caspase of its signalling, caspase-8 (Crowder & El-Deiry, 2012). These
resistance mechanisms include caspase-8 promoter methylation (Grotzer et al, 2000; HopkinsDonaldson
et al, 2000; Hopkins-Donaldson et al, 2003), gene mutations (Kim et al, 2003;
Soung et al, 2005) or a decreased protein stability (Zhang et al, 2005) reported in various cancer
cell types. Furthermore, several studies highlighted an important role of ubiquitination in both
positive (Jin et al, 2009) and negative (Xu et al, 2017) regulation of caspase-8 activity.
Importantly, ubiquitination has also been showed to modulate the function of other TRAIL
DISC components such as DRs, FADD or cFLIP, thus tightly controlling the progress of TRAIL
signalling (Lafont et al, 2018). Therefore, it is likely that “TRAIL’s ubiquitin code“ may
provide a clue for the identification of novel biomarkers of the cell sensitivity to this cytokine,
and that modulators of ubiquitination can represent future promising cancer therapeutic targets
(Lafont et al, 2018).
While the role of caspase-8 in TRAIL-induced apoptosis is well recognized, the
involvement of caspase-10 is less clarified and more controversial. Some studies showed that
caspase-10 is essential for stimulation of TRAIL signalling (Engels et al, 2005; Kischkel et al,
2001), while other reports suggested that it is not important (Seol et al, 2001; Sprick et al,
2002). Recently, caspase-10 has been demonstrated to negatively regulate caspase-8-mediated
cell death induced by ligation of CD95 in cancer cells (Horn et al, 2017). The further details of
the molecular action of caspase-10 in TRAIL-induced signalling remain to be elucidated.
The cFLIP acts as a key determinant of TRAIL sensitivity at the DISC level, and an
important modulator of caspase-8/-10 activity (Fulda, 2013a). Aberrant expression of cFLIP
has been linked to TRAIL resistance in different types of cancer and is often associated with
poor prognosis (MacFarlane et al, 2002; Xiao et al, 2003; Zhang et al, 2004; Zobalova et al,
2008). The targeting of this molecule represents a very promising approach in cancer therapy,
but is rather complicated by the very complex and dynamic regulation of this molecule at the
level of transcription, translation and posttranslational modifications (Shirley et al., 2013).
Moreover, the existence of its individual isoforms (cFLIPL, cFLIPS, cFLIPR), their relative
representation and mutual interplay make it difficult to predict the TRAIL signalling outcome
in particular cancer types, and limit to some extent the usefulness of cFLIP as a biomarker for
TRAIL resistance (Dimberg et al, 2013).
The type II cancer cells can become resistant to TRAIL-induced apoptosis due to
overexpression of anti-apoptotic Bcl-2 family protein such as Mcl-1 (Ricci et al, 2007; SchulzeBergkamen
et al, 2008; Schulze-Bergkamen et al, 2006; Taniai et al, 2004), Bcl-XL (Hinz et
al, 2000; Schulze-Bergkamen et al, 2008) and Bcl-2 (Fulda et al, 2002a; Sinicrope et al, 2004).
On the other hand, loss of expression/function of pro-apoptotic Bcl-2 family members Bax, Bak
or both may confer TRAIL resistance, depending on cancer cell type and its genetic background
(Kandasamy et al, 2003; LeBlanc et al, 2002). Complexity of the whole Bcl-2 protein family,
and redundancy or multiple interactions among its members make it difficult to predict the final
cancer cell response to TRAIL, and the presence/absence of selected single Bcl-2 family
Hyršlová Vaculová 2018
11
molecule often cannot serve as a sufficient biomarker of the cell response to this cytokine
(Dimberg et al, 2013). Therefore, functional analyses such as already mentioned dynamic BH3
profiling could help to better assess the readiness of cancer cells to trigger TRAIL-induced
mitochondrial apoptotic pathway.
Another efficient mechanism how to develop TRAIL resistance is via upregulation of
expression of cIAP family proteins, which has been demonstrated in several cancer cell types
(Cummins et al, 2004; Lippa et al, 2007; Ndozangue-Touriguine et al, 2008; Vogler et al,
2007). An additional level of regulation of XIAP function following TRAIL treatment is further
provided by Smac/DIABLO. The more intensive mitochondrial release of this pro-apoptotic
protein was observed in TRAIL-sensitive compared to TRAIL-resistant cancer cells, and the
Smac/DIABLO-induced inhibition of XIAP was associated with enhanced caspase-3 activation
and TRAIL-induced apoptosis (Zhang et al, 2001). Other members of cIAP family may also
participate in modulation of cancer cell responsiveness to the apoptotic effects of TRAIL
(Finlay et al, 2014; Ricci et al, 2007).
2.2.2. Sensitization to TRAIL-induced apoptosis – combined therapy
Although the success of TRAs used as a stand-alone cancer therapy is very limited,
combined protocols employing TRAs together with other therapeutic approaches are strongly
believed to result in better treatment outcome. Numerous preclinical studies demonstrated that
the resistance to TRAIL-induced apoptosis can be overcome by co-application of sensitizing
agents such as chemotherapeutic drugs, especially platinum-based complexes – cisplatin
(Belyanskaya et al, 2007; Ding et al, 2011; Nagane et al, 2000; Shamimi-Noori et al, 2008;
Tsai et al, 2006; Wu & Kakehi, 2009) or oxaliplatin (El Fajoui et al, 2011; Galligan et al, 2005;
Xu et al, 2009), pyrimidines – 5-fluorouracil (5-FU) (Galligan et al, 2005; Ganten et al, 2004;
Mizutani et al, 2002; Nazim et al, 2017; Stagni et al, 2010; Wang et al, 2015; Yang et al, 2017;
Zhu et al, 2013) or gemcitabine (Hylander et al, 2005; Liu et al, 2001; Xu et al, 2003a; Zhao et
al, 2011), topoisomerase inhibitors – doxorubicin (El-Zawahry et al, 2005; Kang et al, 2005;
Lacour et al, 2003; Wang et al, 2010; Xu et al, 2003b), etoposide (Baritaki et al, 2007; Gibson
et al, 2000; Liu et al, 2001) or camptothecin (Gliniak & Le, 1999; Jayasooriya et al, 2014;
Singh et al, 2003; Yamanaka et al, 2000), and taxanes – paclitaxel (Hunter et al, 2011; Li et al,
2016; Singh et al, 2003) or docetaxel (Jaworska & Szliszka, 2017; Yoo et al, 2008) in various
cancer cell types in vitro or in vivo.
In addition to “classical” chemotherapeutic drugs and radiation (Chinnaiyan et al, 2000;
Kim et al, 2001; Marini et al, 2005; Shankar et al, 2004), different classes of drugs such as
proteasome inhibitors (de Wilt et al, 2013; Koschny et al, 2007a; Naumann et al, 2011; Saulle
et al, 2007; Sayers & Murphy, 2006), epigenetic drugs – histone deacetylase (Earel et al, 2006;
Fulda, 2012; Inoue et al, 2004; Kim et al, 2004; MacFarlane et al, 2005a; Muhlethaler-Mottet
et al, 2006; Nakata et al, 2004; Neuzil et al, 2004; Singh et al, 2005) or methyl transferase
(Braun et al, 2015; Hopkins-Donaldson et al, 2003; Soncini et al, 2013) inhibitors, BH3
(Cristofanon & Fulda, 2012; Huang & Sinicrope, 2008; Song et al, 2008; Wang et al, 2012) or
Smac (Fakler et al, 2009; Fulda et al, 2002b; Lecis et al, 2010; Li et al, 2004; Raulf et al, 2014)
mimetics, various kinase inhibitors (Lemke et al, 2014a; Meng et al, 2007; Ricci et al, 2007;
Rosato et al, 2007), natural compounds found in food or herbs (Beranova et al, 2013; Ganapathy
et al, 2010; Jacquemin et al, 2012; Park et al, 2013; Psahoulia et al, 2007; Tomasetti et al, 2006;
Tomasetti et al, 2004; Weber et al, 2002) and many others have been demonstrated as efficient
in elimination of various types of cancer cells when combined with TRAs.
Hyršlová Vaculová 2018
12
Fig. 5: The extrinsic and intrinsic apoptotic pathways and main points of therapeutic interventions
(Fox & MacFarlane, 2016).
Distinct molecular mechanisms have been suggested to be involved in the cooperative
cytotoxic action of the combination of TRAs and apoptosis-sensitizing drugs such as
upregulation of pro-apoptotic and downregulation of anti-apoptotic proteins, associated with
stimulation of DISC formation or enhanced involvement of mitochondria in type II cells (Fig.
5) (Fox & MacFarlane, 2016; Johnstone et al, 2008; Lemke et al, 2014a; Mahalingam et al,
2009; Newsom-Davis et al, 2009; Trivedi & Mishra, 2015; von Karstedt et al, 2017; Yuan et
al, 2018). However, in many of them, the detailed knowledge on the molecular crosstalk of
signalling pathways simultaneously triggered by these agents, and their complex regulations
are far from being understood. Nevertheless, the above-mentioned findings provided a rationale
to proceed with investigation of the anticancer effects of the combinations of TRAs and selected
promising sensitizers to the already completed or still ongoing phase I/II clinical trials (Dimberg
et al, 2013; Hellwig & Rehm, 2012; Koschny et al, 2007b; Lemke et al, 2014a; Naoum et al,
2017; Papenfuss et al, 2008; Stuckey & Shah, 2013; Yuan et al, 2018). Unfortunately, the
clinically available drug combinations mostly have not achieved sufficient therapeutic activity,
and some of them were discontinued. Therefore, the application of higher affinity TRAs and/or
more potent TRA-sensitizing treatments, optimizing their doses and time sequence/duration of
the treatment, and considering the relevant biomarkers for preselection of suitable patients may
represent the promising approach for maximizing the therapeutic potential of TRAs combined
with conventional or novel sensitizers.
Our research has been focused on the investigation of the molecular mechanisms
responsible for cancer cell sensitization to TRAIL-induced and DR4/5-mediated apoptosis,
which was achieved by application of several classes of therapeutically interesting agents such
as conventionally used or novel chemotherapeutic drugs - cisplatin, LA-12, 5-FU, doxorubicin
or etoposide, epigenetic drugs – 5´-aza-2´-deoxycytidine (decitabine), valproic acid (VPA) or
CI-994, and a dietary polyunsaturated fatty acid with promising anticancer potential –
docosahexaenoic acid (DHA). Our work uncovered novel molecular determinants with
important role in modulation of TRAIL sensitivity by these drugs in several cancer cell types,
especially those of colon, prostate and lung origin, which could be further exploited in future
in order to provide potentially valuable targets for design of more successful therapeutic
Hyršlová Vaculová 2018
13
strategies. The most important results of our work are highlighted and discussed in the
following chapters, and more details can be found within the particular Supplements attached.
2.2.2.1. Platinum drug-mediated sensitization to TRAIL-induced apoptosis
Platinum complexes such as cisplatin, carboplatin and oxaliplatin belong to the most
commonly used chemotherapeutic drugs in cancer treatment (Apps et al, 2015). However, their
application is often limited due to serious side effects and the development of cancer cell
resistance. These limitations evoke a need to uncover yet unknown mechanisms of regulation
of their action and/or search for new analogues with improved anticancer potential. The
promising cytotoxic effects of LA-12, a recently introduced platinum(IV) adamantylaminligand
containing complex (Zak et al, 2004) have been demonstrated in vitro and in vivo by us
and others in various cancer cell types (Bouchal et al, 2011; Horvath et al, 2007; Kvardova et
al, 2010; Prochazka et al, 2007; Roubalova et al, 2010; Sova et al, 2005; Sova et al, 2006). Our
group showed that LA-12 induced a favourable cytotoxic potential in several cisplatin-resistant
cancer cell lines of a different origin (Horvath et al, 2006; Kozubik et al, 2005). LA-12 was
also able to overcome confluence-dependent resistance observed in colon cancer cells treated
with cisplatin or oxaliplatin, which may be a promising advantage in treatment of slowly
growing tumours (Svihalkova-Sindlerova et al, 2010) (Supplement 2). We further showed the
ability of LA-12 to overcome the block in the entry to M phase of the cell cycle observed in
oxaliplatin-treated colon cancer cells. This was associated with a higher cytotoxicity of LA-12
compared to oxaliplatin, probably due to a lack of time for an efficient repair of cellular damage
(Vondalova Blanarova et al, 2013) (Supplement 3). Importantly, in our recent work, we newly
demonstrated that the anticancer properties of LA-12 can be further enhanced by inhibition of
checkpoint kinase 1 (Chk1), a serine/threonine-specific protein kinase critical for the cell cycle
control and coordination of the cell cycle progression in response to DNA damage (Herudkova
et al, 2017) (Supplement 4). The combined treatment with one of the most specific Chk1
inhibitors, SCH900776 (Guzi et al, 2011; Samadder et al, 2017), resulted in a significant
increase in G1/S phase-related LA-12-induced apoptosis, stimulation of mitotic slippage and
senescence in colon cancer cells. We also showed that the presence of functional p53 may
facilitate the drug combination-induced cytotoxicity. Furthermore, the cooperative cytotoxic
effects were significantly accelerated in the absence of p21 and PTEN, and these proteins were
identified as important determinants of the cancer cell response to the combined action of LA-
12 and SCH900776. Our work represents the first demonstration of cooperative anticancer
effects of LA-12 and SCH900776 at all. Previously, only a few studies investigating combined
cytotoxic action of cisplatin and SCH900776 have been reported (Huntoon et al, 2013; Montano
et al, 2012), and in contrast to our observations, they showed no further cancer cell sensitization.
Uniquely, our work uncovered so far unknown antitumor potential of SCH900776 also when
used in combination with cisplatin, and defined some molecular mechanisms involved. Next,
our results also highlighted a remarkable importance of PTEN in modulation of LA-12-induced
caspase-dependent apoptosis that was associated with a significant stimulation of mitochondrial
apoptotic pathway, and occurred preferentially in G1 phase of the cell cycle (Laukova et al,
2015) (Supplement 5). The selected crucial aspects of platinum drug-induced cellular
signalling, with a particular emphasis on LA-12, were summarized in our review article
(Kozubik et al, 2008). Taken together, our research uncovered several important determinants
of platinum drug-induced cytotoxic response in human cancer cells that can be further exploited
in future therapeutic strategies.
Importantly, in addition to exploring its individual potential to trigger cancer cell death
on its own, we investigated the ability of LA-12 to stimulate TRAIL-induced apoptosis in
human cancer cells, and compared its molecular action with the conventionally used cisplatin.
Some studies showed previously that the combined treatment with cisplatin may affect TRAIL-
Hyršlová Vaculová 2018
14
induced signalling via modulation of different steps in apoptotic pathways like DR4/5, cFLIP,
caspases or mitochondria-related events (Ding et al, 2011; Nagane et al, 2000; Shamimi-Noori
et al, 2008; Tsai et al, 2006; Wu & Kakehi, 2009) in various cancer cell types, but the detailed
regulatory mechanisms still remained to be elucidated. Until then, no information regarding the
cooperative cytotoxic action of LA-12 and TRAIL could be found in the literature.
Our initial results newly showed that pre-treatment with sub-toxic concentrations of LA-
12 enhanced the killing action of TRAIL in human colon and prostate cancer cell lines via
stimulation of caspase activity and overall apoptosis (Vondalova Blanarova et al, 2011)
(Supplement 6). The similar cooperative cytotoxic effects were observed using co-treatment
with a 20-fold higher dose of cisplatin, suggesting the higher potential to sensitize to TRAILinduced
apoptosis in case of LA-12. Both platinum drugs significantly modulated the initial
steps in the TRAIL apoptotic pathway - they increased surface or total DR5 level, stimulated
re-localization of DR4 or DR5 into the lipid rafts, and accelerated internalization of TRAIL,
the events that may substantially impact on the DISC complex formation and function. In
addition, we hypothesized that the more downstream interaction of DR-mediated signalling and
mitochondria may be profitable for maximizing of the killing effects of the drug combination,
and explored in more detail the possible involvement of these organelles.
Our subsequent results showed that LA-12 primes human colon cancer cells for TRAILinduced
cell death by p53-independent activation of the mitochondrial apoptotic pathway
(Jelinkova et al, 2014) (Supplement 7). The cooperative cytotoxic action of LA-12 and TRAIL
was associated with stimulation of activation of Bax and Bak proteins, enhanced MOMP and
caspase-9 activation, and an apparent shift of the balance between anti-apoptotic and proapoptotic
Bcl-2 family proteins in favour of the latter ones. Unlike cisplatin, LA-12 was a potent
inducer of ERK-mediated Noxa and BimL protein upregulation, and more effectively enhanced
TRAIL-induced apoptosis in the absence of Bax. The cooperative pro-apoptotic action of LA-
12 and TRAIL was further potentiated by siRNA-mediated silencing of Mcl-1 in both Baxproficient
and -deficient colon cancer cells. We also newly demonstrated that LA-12 triggered
ERK-mediated upregulation of c-Myc, and proved that c-Myc silencing inhibited the
mitochondria-dependent apoptosis following the treatment with LA-12 and TRAIL. Our results
showing similar LA-12-mediated enhancement of TRAIL-induced apoptosis in several colon
cancer cell lines derived from different stages of tumour development further underscored more
general relevance of these findings.
In addition to colon cancer models, we also demonstrated a notable ability of LA-12 or
cisplatin to potentiate TRAIL-induced mitochondrial apoptotic pathway in prostate cancer cells,
which was associated with an enhanced Bid cleavage, Bak activation, drop of mitochondrial
membrane potential, activation of caspases-8, -9, -10 and -3, and XIAP cleavage (Vondalova
Blanarova et al, 2017) (Supplement 8). Employing RNAi approach, we demonstrated that
cisplatin or LA-12 can sensitize cancer cells to TRAIL-induced apoptosis via Bid/Bakdependent
positive mitochondrial feedback amplification loop activation leading to subsequent
secondary enhancement of caspase-8 processing. We showed that Bid is a crucial mediator of
the drug combination-induced cytotoxicity, and it does not require Bak or caspase-10 for its
activation. Although cisplatin/LA-12 and TRAIL combination induced cleavage of caspase-10,
we newly proved that it was dispensable for the cooperative apoptotic effects of drugs observed
in prostate cancer models (Fig. 6) (Vondalova Blanarova et al, 2017). Compared to cisplatin,
significantly lower doses of LA-12 were required for similar sensitizing effects on TRAILinduced
prostate cancer cell apoptosis. This is in agreement with our previous work highlighting
an outstanding apoptosis-inducing or –sensitizing ability of LA-12 when used in apparently
lower doses than some conventional platinum-based drugs (Jelinkova et al, 2014; SvihalkovaSindlerova
et al, 2010), which might provide favourable advantage especially in resistant
tumours. The detailed molecular mechanisms responsible for this phenomenon including the
Hyršlová Vaculová 2018
15
role of previously reported faster and more efficient cellular uptake of LA-12 compared to
cisplatin (Kvardova et al, 2010) need further investigation.
Fig. 6: Cisplatin/LA-12-mediated enhancement of TRAIL-induced apoptosis in prostate cancer cells – main
mechanisms (Vondalova-Blanarova et al, 2017).
A highly frequent resistance to TRAIL-induced apoptosis caused by severe alterations
of crucial components of its signalling pathway was previously reported in a large cohort of
patient prostate cancer tissue samples (Anees et al, 2011), and our own results also support
these findings (Vondalova Blanarova et al, 2017) (Supplement 8). However, we newly
demonstrated the LA-12-mediated enhancement of TRAIL-induced cell death in primary
prostate cancer cells isolated from human patient tumour biopsies. In agreement with the results
of our experiments employing the prostate cancer cell lines, the drug combination-induced
stimulation of cytotoxic response in patient tumour-derived samples was also associated with
activation of mitochondrial apoptotic pathway. These results indicate that anticancer strategies
employing TRAIL combined with platinum-based drugs may represent an efficient approach
for elimination of prostate cancer cells compared to individual action of the drugs. Further
molecular mechanisms involved are currently under investigation in our laboratory.
2.2.2.2. 5-fluorouracil-mediated modulation of TRAIL-DR pathways
Another important chemotherapeutic agent implicated in our work aimed to uncover in
more detail the mechanisms of regulation of TRAIL DR-mediated signalling was 5-FU, a
nucleoside analogue widely used for decades in standard treatment of many cancer types,
particularly colorectal. Although initial response rates for 5-FU-based chemotherapy as a firstline
treatment for this type of advanced cancer were only 10–15%, further improvement (40-
50%) was subsequently achieved by its combination with irinotecan and oxaliplatin (Douillard
et al, 2000; Giacchetti et al, 2000). Nevertheless, as common relapses still occur in a large part
of responding patients, new therapeutic strategies are required to improve their survival. The
anticancer effects of 5-FU are often based on its ability to block thymidylate synthase (TS) and
incorporation of its metabolites into DNA or RNA molecules that finally results in the cell cycle
arrest and/or apoptosis of tumour cells (Longley et al, 2003). However, frequent
chemoresistance is a serious obstacle for successful therapy based on 5-FU. The cell resistance
Hyršlová Vaculová 2018
16
to the 5-FU effects can be associated with alterations in the drug influx or efflux (Nambaru et
al, 2011; Oguri et al, 2007), high levels of TS (Johnston et al, 1995; Peters et al, 2002; van
Triest et al, 1999), defects in the expression or function of DNA mismatch repair genes (Arnold
et al, 2003; Meyers et al, 2004) or overexpression of crucial anti-apoptotic proteins such as
cFLIP (Longley et al, 2006), Bcl-2, Bcl-xL or Mcl-1 (Shi et al, 2002; Violette et al, 2002). The
results of these studies suggest that multiple factors may contribute to 5-FU resistance, and
precise mechanisms involved need deeper elucidation.
Most chemotherapeutic drugs induce cancer cell apoptosis via activation of
mitochondrial pathway, which often requires an involvement of p53. Thus, dysregulation of the
function of this protein or related signalling can often result in the cancer insensitivity to the
treatment. However, these drugs may also induce stimulation of the extrinsic, DR DISCmediated
apoptotic pathway, which can be both p53- dependent and –independent (Sheikh et
al, 1998; Takimoto & El-Deiry, 2000), and understanding of the contribution of this signalling
to the drug-mediated cytotoxicity and the value of its therapeutic targeting warrants further
investigations. Although the status of p53 was proposed as an important player modulating the
colon cancer cell response to 5-FU both in vitro and in vivo, its predictive value is still highly
controversial. Some studies reported that the disruption of p53 function rendered some cancer
cells resistant to 5-FU-induced apoptosis (Bunz et al, 1999; Longley et al, 2002), while others
including us showed that cancer cells with lost wt p53 or mutant p53 could still trigger the
cytotoxic response following treatment with 5-FU, albeit to the lesser extent (Akpinar et al,
2015; Backus et al, 2003; Garcia et al, 2011). Importantly, it has been shown previously that
the inducible silencing of DR5 conferred 5-FU resistance of human colon tumours xenografted
in immunodeficient mice (Wang & El-Deiry, 2004). These findings strongly suggested that
DR5 could be a critical determinant of 5-FU chemosensitivity, but the molecular mechanisms
behind still remained to be elucidated, including the possible involvement of p53.
Our work uncovered novel interesting findings about the role of TRAIL/DR5 and
associated signalling in 5-FU-mediated cytotoxic action in human colon cancer cells (Akpinar
et al, 2015) (Supplement 9). We showed that 5-FU promoted accumulation of DR5 into the
plasma membrane, DISC formation and subsequent caspase activation. The siRNA-mediated
downregulation of DR5, overexpression of cFLIP or FADD-DN abrogated 5-FU-induced cell
death. In the absence of p53, the 5-FU-mediated DR5-DISC formation was slowed down, but
not abrogated. These results indicate that 5-FU can activate DR5-dependent apoptosis
regardless of p53 status, however the p53 presence facilitates extrinsic apoptotic signalling.
Importantly, we also provided a novel evidence of the mechanism by which tumour cells
lacking p53 can be sensitized to 5-FU combinatorial treatment using strategies targeting poly
(ADP-ribose) polymerase-1 (PARP-1).
We further continued our research focused on the more detailed molecular mechanisms
of regulation of TRAIL/DR5-related signalling in colon cancer cells treated with 5-FU (Akpinar
et al, 2016) (Supplement 10). We demonstrated that disruption of lysosomal function by
chloroquine (CQ) suppressed 5-FU-induced apoptosis and delocalized DR5 into cytosol on the
lysosomal and autophagosomal membranes. Using chemical inhibitors, RNAi or genetic
approaches, we showed that correct DR5 transport rather than autophagy itself is an important
factor for 5-FU-induced cytotoxicity. Similarly to CQ, we also showed that brefeldin A (BFA)
that blocks ER to Golgi protein transport abrogated 5-FU cytotoxicity, and delocalized DR5.
Importantly, neither CQ nor BFA were able to impair TRAIL-induced apoptosis, suggesting a
distinct DR5 activation mechanism. We further demonstrated that anticancer response induced
by 5-FU is associated with significant alterations of intracellular DR5 signalling that depends
on proper cholesterol and lysosomal function. Our results suggested a novel molecular
mechanism for DR5 activation induced by 5-FU, important for its anticancer potential.
Hyršlová Vaculová 2018
17
2.2.2.3. Doxorubicin and etoposide as effective sensitizers to TRAIL-induced apoptosis
In addition to colon and prostate cancer models, our work was also focused on the
investigation of TRAIL signalling in small cell lung carcinoma (SCLC), an aggressive tumour
entity with a poor prognosis, which represents a great challenge for novel treatment strategies
as TRAIL monotherapy is here highly inefficient (Hopkins-Donaldson et al, 2003). The failure
of SCLC cells to undergo apoptosis in response to this cytokine has been attributed to the
significant defects at the level of DISC such as the loss of the expression of DR4, DR5, caspase-
10 and caspase-8 (Hopkins-Donaldson et al, 2003; Joseph et al, 1999; Shivapurkar et al, 2002a).
Of them, the most prominent characteristics of the majority of SCLC cells is a frequent loss of
caspase-8. The same phenomenon was also confirmed in our work, where most SCLC cell lines
used in the study were deficient for not only caspase-8, but also caspase-10, thus bearing a
complete block in initiator caspase activation via an extrinsic pathway (Vaculova et al, 2010)
(Supplement 11) and therefore resistant to TRAIL-induced apoptosis. Moreover, we also found
that even caspase-8 expressing SCLC cells did not respond to the apoptotic effects of TRAIL.
Therefore, we investigated whether the cytotoxic effects of TRAIL in SCLC could be restored
by co-treatment with selected sensitizers, and used two different approaches separately for
caspase-8 expressing or lacking SCLC cells.
Firstly, our results demonstrated that doxorubicin or etoposide, the chemotherapeutic
drugs used for treatment of SCLC, could significantly restore the ability of TRAIL to kill
caspase-8 expressing SCLC cells. As TRAIL by itself did not induce caspase-8 processing, it
was likely that the resistance to TRAIL-induced apoptosis was regulated upstream of this
molecule. We demonstrated that doxorubicin mediated sensitization of these cells to the
apoptotic effects of TRAIL that was associated with significant increase of surface and total
DR5 level, strong caspase-8 activation, a specific cleavage of cFLIPL, and a decrease of cFLIPS
level. These events were further accompanied by an enhanced Bid cleavage, Bax activation,
MOMP, cytochrome c release, survivin downregulation, and effector caspase activation. Using
caspase-8 siRNA or a pan-caspase inhibitor z-VAD-fmk, we showed that the co-treatment with
TRAIL and doxorubicin facilitated caspase-8 processing primarily at the DISC level rather than
being a secondary result of activation of mitochondrial pathway or effector caspases. The
sensitization of SCLC cells expressing caspase-8 to TRAIL-induced apoptosis occurred
preferentially at the level DR5 and cFLIP. We proposed that the combined treatment with
TRAIL and conventional chemotherapeutic drugs like doxorubicin or etoposide could represent
an effective killing strategy for SCLC cells proficient but not deficient for caspase-8.
Our second approach was further aimed at investigation of the potential relevance of
TRAIL-based therapy in SCLC cells lacking caspase-8. As the analysis of SCLC tumours
revealed that the methylation of CpG islands in the caspase-8 gene was an important factor
responsible for the loss of its expression (Shivapurkar et al, 2002b), the modulation of
epigenetic mechanisms involved seemed to be a valuable target of the therapeutic interventions.
2.2.2.4. Epigenetic drugs in modulation of TRAIL-induced apoptotic signalling
It has been shown previously that co-treatment of SCLC cells with the demethylating
agent decitabine and interferon- partially restored caspase-8 expression and increased the cell
sensitivity to TRAIL-induced apoptosis (Hopkins-Donaldson et al, 2003), but activation of
other yet uncovered mechanisms seemed to be important for the realization of the full cytotoxic
potential of TRAIL. Similarly, the pharmacologically relevant doses of decitabine slightly
enhanced the expression of caspase-8 in a panel of SCLC cells in our study, but the amount of
caspase-8 was not sufficient to sensitize these cells to TRAIL-induced apoptosis (Kaminskyy
et al, 2011) (Supplement 12). However, we newly demonstrated much more pronounced
effects on both caspase-8 re-expression and TRAIL sensitisation when decitabine was
combined with HDAC inhibitors valproic acid (VPA) or CI-994. The sensitisation to TRAIL-
Hyršlová Vaculová 2018
18
induced apoptosis mediated by the two epigenetic drugs also involved activation of
mitochondrial pathway and caspase-9, and reduction of the level of anti-apoptotic proteins
survivin and cIAP1, indicating that along with the induced level of caspase-8, other factors
might contribute to the effect. This could be attributable to the fact that the epigenetics drugs
used in the study might simultaneously affect the expression or activation of other molecules
with potential impact on apoptotic signalling pathways induced by TRAIL. Nevertheless, we
newly demonstrated that the use of the combination of the inhibitors of DNA methyl
transferases and HDACs represents an effective treatment option for sensitization of SCLC
cells lacking caspase-8 to the killing effects of TRAIL.
2.2.2.5. Docosahexaenoic acid in modulation of TRAIL-induced cell death
Another candidate with potentially interesting sensitizing effects on TRAIL-induced
cytotoxicity examined in our work was docosahexaenoic acid (DHA), a polyunsaturated fatty
acid of n-6 series known for its ability to exert cytostatic or cytotoxic effects in various cancer
cell types, and modulate the expression or activity of molecules relevant for apoptotic signalling
(Lee et al, 2017; Skender et al, 2012). We showed that DHA may affect the cellular lipid
composition and apoptotic signalling of some TNF family members in colon cancer cells
(Hofmanova et al, 2012; Hofmanova et al, 2017; Hofmanova et al, 2014; Hofmanova et al,
2005). We also newly demonstrated that DHA mediated stimulation of TRAIL-induced
apoptosis in SW620 human colon cancer cells that was associated with extensive engagement
of mitochondrial pathway, manifested by Bid cleavage, Bax/Bak activation, drop of MMP,
cytochrome c release, caspase-9 activation and downregulation of XIAP and cIAP1 protein
levels (Vaculova et al, 2005) (Supplement 13), (Skender et al, 2014) (Supplement 14). We
suggested that DHA can prime mitochondria to make them more prone to TRAIL-induced
apoptotic insults. Furthermore, in agreement with previous studies (Jakobsen et al, 2008), our
results demonstrated that DHA induced an activation of endoplasmic reticulum (ER) stress
response. We proposed that ER stress response triggered by DHA could interfere with
mitochondrial signalling and contribute to the cancer cell sensitisation to TRAIL-induced
killing.
We further demonstrated that DHA-mediated enhancement of TRAIL-induced
apoptosis in colon cancer cells was associated with significant changes in the representation of
specific sphingolipid molecules, especially ceramides (Skender et al, 2014) (Supplement 14).
They have been established as important regulators of both intrinsic and extrinsic apoptotic
pathways and ER stress-induced cell death signalling (de Palma & Perrotta, 2012). It has been
shown that specific changes in particular ceramide species can be associated with distinct
cellular responses (Hartmann et al, 2012). Among them, the increased levels of C16-ceramide
have been attributed to the more “pro-apoptotic ceramide phenotype”, while the predominance
of longer chain ceramides rather supported the cell survival. As an example, this phenomenon
was observed in human colon cancer cells isolated from the primary tumour (SW480) and
subsequent metastasis (SW620) of the same patient, which differ substantially in their ability
to undergo TRAIL-induced apoptosis (Voelkel-Johnson et al, 2005). The TRAIL-sensitive
SW480 cells contained higher levels of C16-ceramide and less C24-ceramide when compared
to TRAIL-resistant SW620 cells. In SW480 but not SW620 cells, TRAIL treatment stimulated
further increase in C16-ceramide level, which correlated with apoptosis induction. In addition,
the SW620 cells the resistance to TRAIL was overcome by exogenously added ceramide,
further confirming that defective ceramide signalling may contribute to TRAIL resistance
(Voelkel-Johnson et al, 2005). Building on these studies, we newly suggested that DHAmediated
increase in C16:0 in SW620 cells may help to overcome their defects in ceramide
signalling, thus facilitating apoptosis after exposure to TRAIL. We also showed that DHA and
TRAIL-induced apoptosis was partially blocked by the pre-treatment with fumonisin B1, an
Hyršlová Vaculová 2018
19
inhibitor of ceramide synthases, which further indicated that the changes in the ceramide
signalling may be involved in the stimulation of colon cancer cell apoptosis induced by DHA
and TRAIL. Modulation of ceramide synthase 6 levels were also previously shown to affect
colon cancer cell sensitivity to TRAIL-induced apoptosis (White-Gilbertson et al, 2009). Taken
together, our results highlighted the potential of DHA to enhance the TRAIL-induced selective
elimination of colon cancer cells via simultaneous targeting of multiple steps in apoptotic
pathways.
2.2.2.6. Potential non-selective toxicity of TRAIL-based combination therapy
As specified above, many preclinical studies demonstrated that combination treatments
with TRAIL and chemotherapeutic or chemopreventive drugs can overcome the cell death
resistance in many cancer cell types. However, requirements of anticancer therapy include not
only its high antitumor efficacy, but also minimal toxicity for healthy tissue. Thus, such
combinational approaches can be of clinical benefit only in case that they do not simultaneously
harm normal cells. This issue has to be particularly considered in the treatment of pediatric
cancer patients who have been reported to have a higher risk of developing treatment-associated
toxicities. In an interesting recent study, the authors showed that in contrast to adults, the
mitochondria in the cells derived from normal somatic tissues such as brain, heart, and kidneys
in young children are primed for pro-apoptotic signalling, making them more vulnerable to
undergo cell death in response to the action of some chemotherapeutic drugs or ionizing
radiation (Sarosiek et al, 2017). They showed that apoptosis sensitivity may be dynamically
regulated during postnatal development in some healthy tissues, which could substantially
affect the occurrence of undesired side effects of the anticancer therapies during the human life.
The relatively limited number of currently available studies focused on potentially
undesired toxic effects of TRAIL-based combination therapy in non-cancer cells demonstrated
heterogeneous results, depending on the type of the selected TRAs, their sensitizers and the
treatment schedules (dose, timing, single/multiple applications). While several combination
regimens have been presented as safe for certain types of normal cells, other warn of potentially
dangerous toxicities (Finnberg et al, 2016; Ganten et al, 2006; Koschny et al, 2007c; Van Valen
et al, 2003). The molecular mechanisms involved in the latter scenario remain largely
unexplored, as well as strategies how to manipulate them. Generally, it still remains to be
answered which sensitizing drugs may open the therapeutic window for more effective but still
safe TRAIL-based treatment in particular cancer types.
2.3. TRAIL-induced non-apoptotic signalling
2.3.1. Necroptosis
Numerous recent reports showed that apart from its ability to trigger “classical” caspasedependent
apoptosis, TRAIL can also induce necroptosis, a form of caspase-independent
regulated cell death that critically involves activation of receptor-interacting serine/threonineprotein
kinase 3 or 1 (RIPK3 or RIPK1) (Galluzzi et al, 2018; Grootjans et al, 2017; Su et al,
2016). If caspase-8 is absent or pharmacologically inhibited, apoptosis is prevented and
formation of necrosome, followed by execution of necroptosis may occur alternatively. So far,
only a limited number of recent studies elucidated the involvement of specific molecules and
related regulatory mechanisms of TRAIL-induced necroptosis, as well as the differences
between necroptotic signalling pathways triggered by TRAIL and other TNF family members
(Jouan-Lanhouet et al, 2012; Sosna et al, 2016). It has been shown that TRAIL-induced
necroptosis caused death in various cancer cell types, and impaired their clonogenic survival
Hyršlová Vaculová 2018
20
(Meurette et al, 2005; Meurette et al, 2007; Voigt et al, 2014). Importantly, several
chemotherapeutic drugs have been shown to act in cooperation with TRAIL to stimulate cancer
cell necroptosis, highlighting a potential of combinatorial therapeutic approaches (Voigt et al,
2014). The more precise mechanisms and specific role of necroptosis in TRAIL-induced
anticancer action, together with predictive biomarkers for cancer cell sensitivity to necroptosis
and also possible off-target effects of necroptosis-based therapy remain to be elucidated. They
may uncover yet unknown potential of TRAIL-induced necroptosis as a strategy to overcome
apoptosis resistance in tumour therapy, which is so far almost completely unexplored.
2.3.2. Non-cell death signalling
In addition to apoptosis or necroptosis, TRAIL-induced activation of non-cell death
gene regulatory signalling pathways resulting in stimulation of proliferation and survival has
been demonstrated in various apoptosis-resistant cancer cells or non-transformed normal cells
(Belyanskaya et al, 2008; Ehrhardt et al, 2003; Vilimanovich & Bumbasirevic, 2008).
Moreover, activation of DR4/5-mediated pathway can also be involved in enhancement of
metastatic properties of cancer cells (Ishimura et al, 2006; Trauzold et al, 2006), and even affect
the crucial processes in the tumour microenvironment such as angiogenesis or secretion of proinflammatory
and tumour-promoting cytokines (Hartwig et al, 2017; Leverkus et al, 2003). The
results of the above-mentioned studies highlight a dual role of TRAIL signalling not only in
elimination of cancer cells, but under some circumstances also in stimulation of their
tumorigenic potential. It seems that treatment of certain apoptosis-resistant tumours with TRAs
as a single agents may even increase the risk of worsening the disease progress. Therefore, the
strategies that will help to overcome apoptosis resistance in cancer cells and simultaneously
block the undesired pro-tumorigenic effects of TRAIL are warranted. Selected combined
treatments are believed to shift the outcome of the complex TRAIL-induced signalling in favour
of cell death, thus reducing both on-target adverse effects and off-target toxicities. For the
successful design of such therapeutic strategies, in-depth mechanistic understanding of the cell
death and non-cell death pathways, cross-talks between them, and involvement of regulatory
proteins that can be shared by these pathways, but may undergo specific modifications that may
determine their specific contribution to particular pathway need to be clarified.
In addition to already mentioned DISC (also called TRAIL-R-associated complex I),
ligation of DR4/5 can induce formation of a cytosolic complex II, which consists of caspase-8,
FADD, RIPK1, TNF receptor-associated factor 2 (TRAF2) and NF-B essential modulator
(NEMO), but lacks TRAIL-Rs (Varfolomeev et al, 2005). Until recently, TRAIL-induced “noncytotoxic”
gene activating signalling has been considered as solely associated with the
activation of cytosolic complex II. However, Lafont et al. showed that this signalling can also
be induced via membrane-associated complex I (Lafont et al, 2017). Moreover, they newly
identified LUBAC (the linear ubiquitin chain assembly complex) as a component of both
complex I and II and demonstrated that it is crucial in regulation of the balance between the
different outcomes of TRAIL signalling. The authors suggested that TRAIL-induced cell death
pathways and “non-cytotoxic” gene activation pathways may not be mediated by spatially
distinct signalling complexes, but they are rather finely regulated by ubiquitination events
within the complex I and II, which can both act as “DISCs” or “gene activating platforms”
(Lafont et al, 2018; Lafont et al, 2017). Understanding the molecular mechanisms and kinetics
of these ubiquitination and de-ubiquitination events as well as the specific involvement of
particular kinases will help to understand the “dichotomy” of TRAIL signalling, and identify
novel biomarkers and clinical targets. Within the non-apoptotic TRAIL-induced signalling, the
involvement of various kinases such as RIPK1, IB kinase (IKK), mitogen-activated protein
kinases (MAPKs) – extracellular signal-regulated kinase (ERK), p38 and c-Jun N-terminal
kinase (JNK), phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), Src, transforming
Hyršlová Vaculová 2018
21
growth factor -activated kinase 1 (TAK1) or protein kinase C (PKC) have been reported (Fig.
7) (Azijli et al, 2013; Kretz et al, 2018). However, the preferential activation of specific kinase
cascades triggered by TRAIL in particular cell types, their interactions, and the role of tumour
microenvironment and other factors in modulation of their activation and function need further
clarification.
Fig. 7: TRAIL-induced non-apoptotic signalling (Kretz et al, 2018).
2.3.2.1. NF-B pathway
One of the first discovered “non-canonical” kinase signalling pathways triggered by
TRAIL was activation of transcription factor NF-B, which can be mediated via DR4, DR5 or
DcR2 (Degli-Esposti et al, 1997a; Harper et al, 2001; Ravi et al, 2001; Shetty et al, 2005). It
can involve RIPK1-induced activation of IKK, followed by phosphorylation and proteasomal
degradation of IκB, nuclear translocation of NF-κB, and transcription of anti-apoptotic genes
such as cFLIP, Mcl-1, Bcl-xL or cIAPs (Azijli et al, 2013). Thus, inhibition of NF-B has been
shown as an effective way to enhance TRAIL-induced apoptosis in some cancer cell types
(Dalen & Neuzil, 2003; Harper et al, 2001; Karacay et al, 2004; Roue et al, 2007). On the
contrary, NF-B may also mediate the transcriptional upregulation of TRAIL receptors or some
“pro-apoptotic” genes, and under some circumstances also support the TRAIL-induced cancer
cell apoptosis (Jennewein et al, 2011; Jeremias et al, 1998). This dual role of NF-B signalling
in modulation of apoptotic response elicited by TRAIL needs further elucidation. Moreover,
several studies have shown the importance of NF-B in TRAIL-induced stimulation of
proliferation of some apoptosis-resistant cancer cells (Ehrhardt et al, 2003) or promotion of
cancer cell migration and invasion both in vitro and in vivo (Ishimura et al, 2006; Trauzold et
al, 2006). Therefore, without targeted manipulation, TRAIL-induced activation of NF-B
pathway may represent a potential danger especially in some patients with cell death resistant
tumours (Malhi & Gores, 2006).
Hyršlová Vaculová 2018
22
2.3.2.2. ERK pathway
In addition to NF-B, there is a growing evidence on the role of TRAIL-induced ERK
pathway in stimulation of proliferation of cancer or normal cells, or in mediation of cancer cell
survival and resistance to apoptosis (Azijli et al, 2013; Falschlehner et al, 2007). Regarding the
first issue, TRAIL induced ERK-mediated stimulation of proliferation of caspase-8-deficient
SCLC cells, which was dependent on DR5 and reduced by PD98059, an inhibitor of ERK
pathway, was reported (Belyanskaya et al, 2008). TRAIL also induced proliferation of human
glioma cells mediated via activation of ERK pathway that was dependent on cFLIPL
(Vilimanovich & Bumbasirevic, 2008). TRAIL-induced ERK-mediated enhancement of
proliferation was further demonstrated in normal human preadipocytes, vascular endothelial
and smooth muscle cells, highlighting the role of TRAIL in modulation of the normal tissue
physiology and homeostasis (Funcke et al, 2015; Secchiero et al, 2003; Secchiero et al, 2004).
Second, various studies also showed the importance of ERK pathway in modulation of
TRAIL-induced cytotoxicity. In many but not all cases, TRAIL-induced activation of ERK
pathway has been associated with the cancer cell protection from apoptosis. TRAIL-induced
ERK activation was reported to prevent human melanoma cell apoptosis by inhibition of relocalization
of Bax protein to mitochondria and subsequent blockage of mitochondrial release
of Smac/DIABLO (Zhang et al, 2003). The protective effect of ERK pathway on DR-mediated
apoptosis was also demonstrated in HeLa cervical cancer cells, most probably at the level or
upstream of caspase-8 (Tran et al, 2001). In our work, we showed that TRAIL triggered a strong
ERK1/2 phosphorylation accompanied by an increase in Mcl-1 protein level in HT-29 human
colon cancer cells. The chemical inhibition of ERK pathway markedly sensitized these cells to
apoptosis induction by this cytokine, which was associated with a significant enhancement of
caspase-8,-9,-3 activation and their substrate cleavage, drop in MMP, and a loss of Mcl-1
protein (Vaculova et al, 2006) (Supplement 15), (Hofmanova et al, 2008) (Supplement 16).
In our subsequent study, we further proved that TRAIL-induced activation of ERK was
functionally important for early upregulation of Mcl-1 at the level of both mRNA and protein.
The siRNA-mediated silencing of Mcl-1 significantly enhanced TRAIL-induced apoptosis and
related changes at the level of mitochondria (Vaculova et al, 2009) (Supplement 17). On the
other hand, a pre-treatment with epidermal growth factor (EGF), a well-known activator of
ERK pathway, resulted in further increase in TRAIL-induced Mcl-1 protein level and supported
the cell resistance to the apoptotic effects of this cytokine. Taken together, our results
documented that TRAIL can simultaneously activate both caspase-mediated apoptotic as well
as ERK kinase-mediated pro-survival signalling, and described the molecular mechanisms of
the cross-talk between them at the level of anti-apoptotic Bcl-2 family member Mcl-1, an
important regulator of cancer cell sensitivity to TRAIL (Ricci et al, 2007).
2.3.2.3. PI3K/Akt pathway
Similarly as in case of ERK pathway, numerous reports also demonstrated the
propensity of TRAIL-induced PI3K/Akt pathway to enhance proliferation or support survival
in normal and cancer cells, and inhibition of this pathway often reverted the cancer cell
sensitivity to apoptotic effects of TRAIL (Liu et al, 2010; Morel et al, 2005; Xu et al, 2010;
Zauli et al, 2005). While the elevated Akt activity has been shown to protect many cancer cell
types from TRAIL-induced apoptosis (Dida et al, 2008; Goncharenko-Khaider et al, 2010;
Chen et al, 2001; Lalaoui et al, 2001; Nesterov et al, 2001; Puduvalli et al, 2005), it was
ineffective in others (Efron et al, 2006). We showed that LY294002-mediated inhibition of
PI3K/Akt pathway significantly enhanced TRAIL-induced apoptosis in colon cancer cells,
which was associated with stimulation of caspase activation and involvement of mitochondria
(Vaculova et al, 2006) (Supplement 15). These pro-apoptotic effects induced by the
Hyršlová Vaculová 2018
23
combination of TRAIL and LY294002 were not mediated via downregulation of Mcl-1 protein
as we observed following treatment with TRAIL and ERK inhibitors, suggesting that in these
cells ERK or PI3K/Akt employ distinct molecular mechanisms in order to protect from TRAILinduced
apoptosis.
In addition to regulation of the proliferation and survival, PI3K/Akt pathway also plays
an important role in modulation of cell invasiveness and migration (Agarwal et al, 2013). It has
been shown that changes in activity of this pathway may be related to alterations in cell adhesive
properties that frequently occur especially in metastatic cancers. In our further work, we showed
that compared to adherently cultivated (attached) colon cancer cells, the activation of PI3K/Akt
pathway was significantly enhanced in their non-adherently cultivated (detached) counterparts
that were resistant to anoikis, a specific variant of apoptosis induced by the loss of integrindependent
anchorage (Galluzzi et al, 2018). Furthermore, we observed that the detachmentinduced
activation of PI3K/Akt pathway in colon cancer cells was associated with an increase
in their resistance to TRAIL-induced apoptosis, and inhibition of this pathway resulted in reactivation
of apoptotic response to this cytokine (Koci et al, 2011) (Supplement 18). In
contrast, another study showed a decrease in Akt phosphorylation and an enhancement of
TRAIL-induced apoptosis in detached ovarian cancer cells (Lane et al, 2008). An additional
increase in TRAIL-induced killing of these cells was further observed under the inhibition of
Akt pathway by LY294002. The results obtained by us and others suggest that despite the
differences in regulation of basal PI3K/Akt activity in different cell/tumour types, targeted
inhibition of this pathway may serve as a useful approach to prime numerous resistant cancer
cells to TRAIL‐induced apoptosis.
2.4. TRAIL-induced apoptotic versus non-apoptotic signalling
TRAIL-induced apoptotic signalling belongs to the best-characterized apoptotic
pathways and harbours a great potential for exploitation in cancer therapy. However, despite its
name (“apoptosis-inducing ligand”), the induction of apoptosis is only one of the biological
effects that can be triggered by this cytokine (Fulda, 2013b). Although so far less well
understood, it is unequivocally clear that so-called non-canonical TRAIL-induced signalling
represents a potential risk of TRAIL-based anticancer therapies. As already mentioned, the
engagement of non-canonical signalling not only hampers TRAIL-induced apoptosis in cancer
cells, but also encourages the development of the malignant phenotype by enhancing their
proliferation, survival, migration and metastasis (Fig. 8) (Bertsch et al, 2014). However, it
remains to be better understood if or under which conditions TRAIL induces such signalling
events preferentially/exclusively in apoptosis-resistant cancer cells or how relevant it is in
tumours that are responsive to TRAIL-induced killing. It has been shown that TRAIL can
activate both canonical and non-canonical signalling pathways in clonal cancer cell populations
within the heterogeneous tumour, where some of the cell subpopulations undergo apoptosis,
while other survive and develop acquired resistance to TRAIL-induced killing. This
phenomenon called a fractional survival may contribute to failure of TRAIL-based therapy and
enable further tumour propagation (Flusberg et al, 2013; Shlyakhtina et al, 2017).
2.4.1. Pleiotropic function of DR4/5 during carcinogenesis
Different types of deregulations at the DR4/5 level expression and function, and changes
in sensitivity/resistance to TRAIL effects may frequently occur during carcinogenesis in
various tumours. A high frequency of the deficiency of DR4/5 on the surface plasma membrane
has been demonstrated in various cancer cell types (Gallmeier et al, 2013; Hopkins-Donaldson
et al, 2003; Horak et al, 2005; Jin et al, 2004; Ozoren et al, 2000; Zhang & Zhang, 2008).
Although the complete loss of both surface DR4 and DR5 in cancer cells is not so frequent, the
Hyršlová Vaculová 2018
24
absence of one of them may be sufficient to induce TRAIL resistance. In some of these cases,
combination therapies that either facilitate TRAIL-induced apoptotic signalling via the
remaining receptor or help to re-establish the expression of the missing receptor can restore the
cancer cell sensitivity to the killing effects of TRAIL (Pennarun et al, 2010). However, the
increase in surface DR level mediated by the sensitizing drugs used in combination with TRAs
may under some circumstances serve as a double-edge sword as in addition to potentiation of
apoptotic effects, it can also stimulate the non-canonical signalling in cancer cells. Therefore,
combination of TRAIL DR agonists with cell death sensitizers and at the same time compounds
hampering the stimulation of undesired pro-tumorigenic events (e.g. specific kinase inhibitors)
is required to ensure the efficient execution of cancer-selective death while countering the
manifestation of tumour-promoting features (Shlyakhtina et al, 2017).
Fig. 8: Pleiotropic functions of plasma membrane-localized TRAIL DRs (Bertsch et al, 2014).
On the contrary, there are also studies showing an increase in DR4/5 expression during
carcinogenesis, e.g. in cervical, pancreatic or colorectal cancer cell lines or patient-derived
colorectal tumours (Jalving et al, 2014; Koornstra et al, 2003; Ozawa et al, 2001; Ryu et al,
2000). In addition, a high DR4/5 expression was associated with worse overall patient survival
in some cancers (Dong et al, 2008; Ganten et al, 2009; McCarthy et al, 2005; van Geelen et al,
2006). These findings suggest that the elevation of DR4/5 expression during cancer
development may provide tumours with growth advantages rather than support their proapoptotic
phenotype. In such tumours, the activation of DR4/5 signalling predominantly
contributes to cancer promotion, and its targeted inhibition may be beneficial in cancer
treatment strategies.
Thus, depending on the tumour type or the cellular context, TRAIL DRs have been
shown stimulate pleiotropic signalling resulting either in suppression of tumour initiation and
metastasis (Cretney et al, 2002; Grosse-Wilde et al, 2008) or promotion of cancer cell migration
Hyršlová Vaculová 2018
25
and invasion (Ishimura et al, 2006; Trauzold et al, 2006; von Karstedt et al, 2015).
Interestingly, the oncogenic K-Ras was proposed as a critical factor in switching the proapoptotic
function of TRAIL DRs into pro-metastatic ones in human and mouse colorectal
cancer cells, suggesting the potential adverse effects of treatment with DR4/5 agonists in
patients with K-Ras mutated tumours (Hoogwater et al, 2010; von Karstedt et al, 2015). The
results of these studies showed that TRAIL DR signalling is much more pleiotropic than
initially thought, and further clarification of its molecular complexity and crucial determinants
is urgently needed in order to make a right selection of patients who may benefit from TRAIL
treatment.
2.4.2. DR4/5-specific signalling in cancer
Another important aspect that has to be considered is the phenomenon of differences in
a relative contribution of surface DR4 or DR5 to apoptotic and non-apoptotic signalling in
various cancer cell types. For example, primary cells derived from patients with chronic
lymphocytic leukemia, mantle cell lymphoma or human pancreatic ductal adenocarcinoma cells
trigger apoptosis almost exclusively through DR4 but not DR5 (Lemke et al, 2010; MacFarlane
et al, 2005). In contrast, cancer cell lines derived from colon and breast tumours signal primarily
through DR5 although they express both DRs at the surface (Kelley et al, 2005). Although there
are reports showing preferential induction of apoptosis via either DR4 or DR5 in different cell
types and conditions, DR5 is generally considered as more potent apoptotic mediator compared
with DR4 (Kelley et al, 2005; Truneh et al, 2000). In agreement with these findings, results of
our work also showed that the chemotherapy-mediated sensitization of SCLC or colon cancer
cells to TRAIL-induced apoptosis occurred preferentially at the level of DR5 (Vaculova et al,
2010) (Supplement 11), (Vondalova Blanarova et al, 2011) (Supplement 6). Similarly, ABT-
737- or homoharringtonine-mediated enhancement of TRAIL-induced apoptosis also
proceeded predominantly via the DR5 receptor in colon cancer cells (Nahacka et al, 2018).
Compared to apoptosis pathways, fewer studies explored the relative contribution of
DR4/5 to TRAIL-induced non-apoptotic kinase-mediated signalling. Activation of NF–κB
following TRAIL stimulation was exclusively driven by DR4 and not inhibited by DR5
blocking antibody in pancreatic ductal adenocarcinoma cells (Lemke et al, 2010). In contrast,
TRAIL-induced non-canonical kinase-mediated migratory and invasive features in apoptosis
resistant NSCLC cells were predominantly mediated by DR5 (Azijli et al, 2012). Another group
also reported a differential contribution of DR4/5 to JNK-mediated signalling in HeLa cells
treated with TRAIL or agonistic DR-selective monoclonal antibodies (Muhlenbeck et al, 2000).
An interesting recent study provided a first systematic insight into complex DR4/5-specific
signalling in colorectal and pancreatic cell lines. The authors showed that DR5 plays a major
role in TRAIL-induced non-canonical kinase signalling, but not in the induction of necroptosis
(Nahacka et al, 2018). It is evident that the efficacy of the combined TRAIL-based therapy can
be substantially affected by the appropriate selection of particular DR4/5-specific recombinant
TRAIL ligand variants or monoclonal antibodies and/or the co-treatment with sensitizing agents
primarily influencing the regulation of DR4- or DR5-specific signalling.
2.4.3. DR4/5 compartmentalization in TRAIL signalling
Until recently, mostly the total or surface level of DR4/5 was investigated as a
prognostic marker for cancer development and therapy. However, there is an increasing number
of publications showing that DR4/5 are abundantly present in other previously unexplored
subcellular localizations, especially in cancer cells. Besides plasma membrane and the
membranes of secretory or endocytic/lysosomal compartments, TRAIL DRs can also be found
in autophagosomes, soluble within the cytoplasm or in the nucleus (Bertsch et al, 2014;
Twomey et al, 2015). In these locations, DR4/5 seem to exert specific yet uncharacterized
Hyršlová Vaculová 2018
26
functions rather than only contribute to apoptotic or non-apoptotic signalling pathways initiated
within the plasma membrane (Bertsch et al, 2014). The recent discoveries clearly showed that
subcellular localization of DR5 and the related regulatory events represent important factors
that determine the final output of DR-mediated signalling, and elucidation of these mechanisms
will substantially change the understanding of TRAIL biology. Importantly, the presence of
DR4/5 in specific subcellular compartments could be used as a predictive biomarker to identify
the patients that are most likely to respond to TRA-based therapy (Mert & Sanlioglu, 2017).
One of the events that can significantly contribute to the modulation of the DR4/5
intracellular trafficking and localization is endocytosis (Repnik et al, 2013). The internalized
receptors can be transported through early to late endosomes and lysosomes, which may be
followed by receptor degradation. On the other hand, internalized receptors can be delivered
back to the plasma membrane during the process of their recycling. The functional relevance of
the dynamic endosomal DR compartmentalization is still incompletely understood, especially
with regard to its involvement in modulation of related apoptotic and non-apoptotic cellular
signalling. In contrast to TNF – TNF-R1 or Fas – FasL, where the endocytosis has been shown
as a positive factor in enhancing their pro-apoptotic signalling, the role of endocytosis in
apoptosis triggered via TRAIL – DR4/5 is much more controversial and the cell type-specific
(Schneider-Brachert et al, 2013; Twomey et al, 2015). Blockage of TRAIL – DR4/5
internalization did not inhibit the formation of the DISC, caspase-8 activation and further
propagation of apoptosis signal in BJAB Burkitt lymphoma B cells (Kohlhaas et al, 2007). On
the contrary, inhibition of endocytosis restored cell surface DR4/5 expression and sensitized
breast cancer cells to TRAIL-induced apoptosis (Zhang & Zhang, 2008). DR5 internalization
was also essentially required for rapid lysosomal permeabilization, cathepsin B release and
apoptosis execution in hepatocellular and cholangiocarcinoma cells (Akazawa et al, 2009).
Besides apoptosis, even less is known about the possible impact of DR4/5 endocytosis on the
outcome of TRAIL-induced non-apoptotic intracellular signalling.
In our work, we investigated in detail the role of endocytosis and endosomal trafficking
in modulation of TRAIL-induced apoptotic and non-apoptotic signalling in human colon cancer
cells (Horova et al, 2013) (Supplement 19). We showed that TRAIL-induced apoptosis can be
significantly reduced upon blocking endosomal acidification by the vacuolar ATPase (VATPase)
inhibitors bafilomycin A1 or concanamycin A. In the cells pre-treated with these
inhibitors, the TRAIL-induced processing of caspase-8 and the aggregation and trafficking of
the TRAIL receptor complexes were temporarily attenuated. These effects were not related to
the possible suppression of lysosomal membrane permeabilization or activity of acidic
sphingomyelinase. Importantly, the V-ATPase inhibitors did not affect the TRAIL-induced NFB
or ERK activation observed in these cells, suggesting that their function was restricted
mainly to the pro-apoptotic arm of TRAIL signalling. Our data demonstrated that endosomal
acidification represents an important regulatory node in the proximal part of TRAIL-induced
pro-apoptotic signalling, while it did not seem to substantially affect the TRAIL-induced nonapoptotic
events. In addition to the continuous need to delineate the detailed role of endocytosis
in regulation of DR4/5-mediated signalling, there are also numerous open questions on whether
and how specific DR signalling reciprocally regulates the endocytic machinery. Recently, it has
been shown that TRAIL-induced early stimulation of caspase-8 results in activation of dynamin
1 (Dyn1), Dyn1-dependent endocytosis of DR4/5, and suppression of TRAIL-induced
apoptosis in some cancer cells (Reis et al, 2017). Thus, the deregulations at the level of DR4/5
endocytosis may represent an interesting adaptation of cancer cells to modulate their survival
and tumorigenic potential, and a potential therapeutic target to combat this disease.
Furthermore, as mentioned above, a nuclear expression of DR5 in some cancer cell types
was recently recognized as a novel phenomenon significantly affecting the outcome of TRAIL
signalling (Kriegl et al, 2012; Leithner et al, 2009). The DR5 molecule contains two nuclear
Hyršlová Vaculová 2018
27
localization signals and possess the ability to undergo 1-importin-mediated nuclear
translocation (Kojima et al, 2011). The origin of nuclear DR5 as well as the mechanisms
responsible for shuttling between different compartments remain to be elucidated in more
detail. Within the nucleus, DR5 has been demonstrated to interact with the microprocessor
complex and its accessory proteins, which results in impaired maturation of let-7 miRNA, a
negative regulator of several proliferation-driving molecules including K-Ras mRNA
(Haselmann et al, 2014; Kretz et al, 2018). Thus, nuclear DR5 can enhance cancer cell
proliferation and contribute to malignancy, even in a TRAIL-independent manner (Mert &
Sanlioglu, 2017). These findings revealed additional crucial aspects of TRAIL DR-mediated
signalling and stimulated the search for yet unknown nuclear functions of not only DR5, but
also DR4 or DcR1/2, which may open new therapeutic opportunities based on targeting these
receptor-dependent nuclear events.
Thus, based on the results of numerous publications, the preferential induction of
apoptosis in cancer versus normal cells has been recognized as a strong selective advantage of
TRAIL-based therapy for a long time. Recently, an increasing knowledge on the ability of
TRAIL to stimulate non-cell death pathways in cancer cells revealed the need to block these
pathways in order to maximize the therapeutic benefit of the TRAs therapy. However, as similar
pro-survival pathways are also activated by TRAIL in normal cells, it remains to be explored
whether the application of this combined treatments could simultaneously enhance undesired
toxic side effects on normal cells, reducing the therapeutic window of TRAIL-based therapy.
The limited evidence obtained so far showed that combined treatments that block the TRAILinduced
non-cell death pathways may preferentially sensitize cancer but not most normal cells
to TRAIL-induced cytotoxicity (Fulda, 2013b). However, further investigations will reveal
whether this phenomenon may also be observed repeatedly using other yet unexplored normal
cell types, and finally also in the clinical settings.
Hyršlová Vaculová 2018
28
3. Summary and future perspectives
An efficient and selective induction of cancer cell death is a main aim of many therapeutic
approaches, and identification of the suitable candidates that are capable to do so represents a
continuous need in oncology. Within this work, we investigated the TRAIL signalling and its
fascinating biology from the different points of view, exploring its outstanding ability to act as
a unique cancer-selective killer and, on the other hand, as a dangerous weapon that could be
used by some cancer cells to support their malignant behaviour. To distinguish between these
potent contradictory properties of this enormously interesting cytokine is an essential
precondition of its successful therapeutic application and a great challenge for many scientists
around the world including us. Our work contributed to the better understanding of the “two
faces” of TRAIL signalling in cancer cells, with a particular focus on the mechanisms of
resistance to TRAIL-induced apoptosis observed in numerous cancer cell types. We put our
efforts into elucidation of molecular mechanisms and strategies how to enhance the anticancer
potential of TRAIL and at the same time to shed more light on the “dark side” of its signalling
that should be prevented in order to eliminate the undesired side effects of TRAIL-based
therapy. In order to boost the cytotoxic potential of TRAIL in cancer cells, we investigated the
apoptosis-sensitizing abilities of several classes of potentially interesting therapeutic agents conventionally
used or recently introduced chemotherapeutic drugs such as cisplatin, LA-12,
5-FU, doxorubicin or etoposide, epigenetic drugs – decitabine or VPA, and dietary
polyunsaturated fatty acid DHA. We newly described several molecular determinants of their
cooperative cytotoxic action with TRAIL at the different levels of apoptotic signalling
pathways, including DRs, DISC, mitochondria and caspases in several cancer cell types. In
addition, our work also uncovered novel details about the role of kinase-mediated non-cell death
signalling in regulation of cancer cell sensitivity to the apoptotic effect of TRAIL, with a
particular attention to MAPK/ERK and PI3K/Akt. Our results identified possible cross-talks
between TRAIL-induced apoptotic and kinase signalling in cancer cells, and their impact
especially at the cell death-related events at the level of mitochondria.
Due to the complexity of TRAIL/TRAIL-R system, further intensive research is required
to fully understand the dichotomy of its signalling, individual regulatory pathways, cross-talks
between them, molecular switches and factors that may affect it, and the biological
consequences. Many of these issues that deserve our attention were already mentioned within
this theses, and represent important milestones for the future research efforts. Unfortunately,
the ability of some cancer cells to escape from TRAIL-induced killing action still remains a
serious limitation that prevents its successful therapeutic application. The deeper insights into
the underlying mechanisms of TRAIL resistance in cancer and normal cells and expanded
knowledge about the new ways of sensitization to TRAIL-induced apoptosis will enable to
understand which conditions need to be fulfilled to efficiently exploit the anticancer potential
of TRAIL. These findings will also be crucial for determination of predictive biomarkers for
individualized selection of patients eligible for tailored DR4/5-targeted therapy. Finally,
combining TRAIL receptor agonists with current or recently developed agents that will
sensitize the cancer cells to apoptosis and simultaneously inhibit the kinase signalling
promoting cancer cell survival seems to be the best way how to provide a greater clinical benefit
of this extraordinary “apoptotic” molecule. The future research will show if we are able to
design such efficient anticancer strategies and prove their clinical relevance, and confirm that
we are on the “right trail”.
Hyršlová Vaculová 2018
29
4. References
Adams JM, Cory S (2018) The BCL-2 arbiters of apoptosis and their growing role as cancer targets.
Cell Death Differ 25: 27-36
Agarwal E, Brattain MG, Chowdhury S (2013) Cell survival and metastasis regulation by Akt signaling
in colorectal cancer. Cell Signal 25: 1711-9
Akazawa Y, Mott JL, Bronk SF, Werneburg NW, Kahraman A, Guicciardi ME, Meng XW, Kohno S,
Shah VH, Kaufmann SH, McNiven MA, Gores GJ (2009) Death receptor 5 internalization is required
for lysosomal permeabilization by TRAIL in malignant liver cell lines. Gastroenterology 136: 2365-
2376 e1-7
Akpinar B, Bracht EV, Reijnders D, Safarikova B, Jelinkova I, Grandien A, Vaculova AH,
Zhivotovsky B, Olsson M (2015) 5-Fluorouracil-induced RNA stress engages a TRAIL-DISCdependent
apoptosis axis facilitated by p53. Oncotarget 6: 43679-97
Akpinar B, Safarikova B, Laukova J, Debnath S, Vaculova AH, Zhivotovsky B, Olsson M (2016)
Aberrant DR5 transport through disruption of lysosomal function suggests a novel mechanism
for receptor activation. Oncotarget 7: 58286-58301
Anees M, Horak P, El-Gazzar A, Susani M, Heinze G, Perco P, Loda M, Lis R, Krainer M, Oh WK
(2011) Recurrence-free survival in prostate cancer is related to increased stromal TRAIL expression.
Cancer 117: 1172-82
Apps MG, Choi EH, Wheate NJ (2015) The state-of-play and future of platinum drugs. Endocr Relat
Cancer 22: R219-33
Arnold CN, Goel A, Boland CR (2003) Role of hMLH1 promoter hypermethylation in drug resistance
to 5-fluorouracil in colorectal cancer cell lines. Int J Cancer 106: 66-73
Ashkenazi A, Pai RC, Fong S, Leung S, Lawrence DA, Marsters SA, Blackie C, Chang L, McMurtrey
AE, Hebert A, DeForge L, Koumenis IL, Lewis D, Harris L, Bussiere J, Koeppen H, Shahrokh Z,
Schwall RH (1999) Safety and antitumor activity of recombinant soluble Apo2 ligand. J Clin Invest
104: 155-62
Azijli K, Weyhenmeyer B, Peters GJ, de Jong S, Kruyt FA (2013) Non-canonical kinase signaling by
the death ligand TRAIL in cancer cells: discord in the death receptor family. Cell Death Differ 20:
858-68
Azijli K, Yuvaraj S, Peppelenbosch MP, Wurdinger T, Dekker H, Joore J, van Dijk E, Quax WJ, Peters
GJ, de Jong S, Kruyt FA (2012) Kinome profiling of non-canonical TRAIL signaling reveals RIP1Src-STAT3-dependent
invasion in resistant non-small cell lung cancer cells. J Cell Sci 125: 4651-61
Backus HH, Wouters D, Ferreira CG, van Houten VM, Brakenhoff RH, Pinedo HM, Peters GJ (2003)
Thymidylate synthase inhibition triggers apoptosis via caspases-8 and -9 in both wild-type and
mutant p53 colon cancer cell lines. Eur J Cancer 39: 1310-7
Baritaki S, Huerta-Yepez S, Sakai T, Spandidos DA, Bonavida B (2007) Chemotherapeutic drugs
sensitize cancer cells to TRAIL-mediated apoptosis: up-regulation of DR5 and inhibition of Yin
Yang 1. Mol Cancer Ther 6: 1387-99
Hyršlová Vaculová 2018
30
Belyanskaya LL, Marti TM, Hopkins-Donaldson S, Kurtz S, Felley-Bosco E, Stahel RA (2007) Human
agonistic TRAIL receptor antibodies Mapatumumab and Lexatumumab induce apoptosis in
malignant mesothelioma and act synergistically with cisplatin. Mol Cancer 6: 66
Belyanskaya LL, Ziogas A, Hopkins-Donaldson S, Kurtz S, Simon HU, Stahel R, Zangemeister-Wittke
U (2008) TRAIL-induced survival and proliferation of SCLC cells is mediated by ERK and
dependent on TRAIL-R2/DR5 expression in the absence of caspase-8. Lung Cancer 60: 355-65
Beranova L, Pombinho AR, Spegarova J, Koc M, Klanova M, Molinsky J, Klener P, Bartunek P, Andera
L (2013) The plant alkaloid and anti-leukemia drug homoharringtonine sensitizes resistant human
colorectal carcinoma cells to TRAIL-induced apoptosis via multiple mechanisms. Apoptosis 18: 739-
50
Bertsch U, Roder C, Kalthoff H, Trauzold A (2014) Compartmentalization of TNF-related apoptosisinducing
ligand (TRAIL) death receptor functions: emerging role of nuclear TRAIL-R2. Cell Death
Dis 5: e1390
Bin L, Thorburn J, Thomas LR, Clark PE, Humphreys R, Thorburn A (2007) Tumor-derived mutations
in the TRAIL receptor DR5 inhibit TRAIL signaling through the DR4 receptor by competing for
ligand binding. J Biol Chem 282: 28189-94
Bouchal P, Jarkovsky J, Hrazdilova K, Dvorakova M, Struharova I, Hernychova L, Damborsky J, Sova
P, Vojtesek B (2011) The new platinum-based anticancer agent LA-12 induces retinol binding
protein 4 in vivo. Proteome Sci 9: 68
Braun FK, Mathur R, Sehgal L, Wilkie-Grantham R, Chandra J, Berkova Z, Samaniego F (2015)
Inhibition of methyltransferases accelerates degradation of cFLIP and sensitizes B-cell lymphoma
cells to TRAIL-induced apoptosis. PLoS One 10: e0117994
Bunz F, Hwang PM, Torrance C, Waldman T, Zhang Y, Dillehay L, Williams J, Lengauer C, Kinzler
KW, Vogelstein B (1999) Disruption of p53 in human cancer cells alters the responses to therapeutic
agents. J Clin Invest 104: 263-9
Calvino Fernandez M, Parra Cid T (2010) H. pylori and mitochondrial changes in epithelial cells. The
role of oxidative stress. Rev Esp Enferm Dig 102: 41-50
Campbell KJ, Tait SWG (2018) Targeting BCL-2 regulated apoptosis in cancer. Open Biol 8, 180002
Cretney E, Takeda K, Yagita H, Glaccum M, Peschon JJ, Smyth MJ (2002) Increased susceptibility to
tumor initiation and metastasis in TNF-related apoptosis-inducing ligand-deficient mice. J Immunol
168: 1356-61
Cristofanon S, Fulda S (2012) ABT-737 promotes tBid mitochondrial accumulation to enhance TRAILinduced
apoptosis in glioblastoma cells. Cell Death Dis 3: e432
Crowder RN, El-Deiry WS (2012) Caspase-8 regulation of TRAIL-mediated cell death. Exp Oncol 34:
160-4
Cummins JM, Kohli M, Rago C, Kinzler KW, Vogelstein B, Bunz F (2004) X-linked inhibitor of
apoptosis protein (XIAP) is a nonredundant modulator of tumor necrosis factor-related apoptosisinducing
ligand (TRAIL)-mediated apoptosis in human cancer cells. Cancer Res 64: 3006-8
Czabotar PE, Lessene G, Strasser A, Adams JM (2014) Control of apoptosis by the BCL-2 protein
family: implications for physiology and therapy. Nat Rev Mol Cell Biol 15: 49-63
Hyršlová Vaculová 2018
31
Dalen H, Neuzil J (2003) Alpha-tocopheryl succinate sensitises a T lymphoma cell line to TRAILinduced
apoptosis by suppressing NF-kappaB activation. Br J Cancer 88: 153-8
de Miguel D, Lemke J, Anel A, Walczak H, Martinez-Lostao L (2016) Onto better TRAILs for cancer
treatment. Cell Death Differ 23: 733-47
de Palma C, Perrotta C (2012) Ceramide as target of chemotherapy: its role in apoptosis and autophagy.
Clinical Lipidology 7: 111-119
de Wilt LH, Kroon J, Jansen G, de Jong S, Peters GJ, Kruyt FA (2013) Bortezomib and TRAIL: a perfect
match for apoptotic elimination of tumour cells? Crit Rev Oncol Hematol 85: 363-72
Degli-Esposti MA, Dougall WC, Smolak PJ, Waugh JY, Smith CA, Goodwin RG (1997a) The novel
receptor TRAIL-R4 induces NF-kappaB and protects against TRAIL-mediated apoptosis, yet retains
an incomplete death domain. Immunity 7: 813-20
Degli-Esposti MA, Smolak PJ, Walczak H, Waugh J, Huang CP, DuBose RF, Goodwin RG, Smith CA
(1997b) Cloning and characterization of TRAIL-R3, a novel member of the emerging TRAIL
receptor family. J Exp Med 186: 1165-70
Del Gaizo Moore V, Letai A (2013) BH3 profiling--measuring integrated function of the mitochondrial
apoptotic pathway to predict cell fate decisions. Cancer Lett 332: 202-5
Delbridge AR, Strasser A (2015) The BCL-2 protein family, BH3-mimetics and cancer therapy. Cell
Death Differ 22: 1071-80
Dickens LS, Powley IR, Hughes MA, MacFarlane M (2012) The 'complexities' of life and death: death
receptor signalling platforms. Exp Cell Res 318: 1269-77
Dida F, Li Y, Iwao A, Deguchi T, Azuma E, Komada Y (2008) Resistance to TRAIL-induced apoptosis
caused by constitutional phosphorylation of Akt and PTEN in acute lymphoblastic leukemia cells.
Exp Hematol 36: 1343-53
Dimberg LY, Anderson CK, Camidge R, Behbakht K, Thorburn A, Ford HL (2013) On the TRAIL to
successful cancer therapy? Predicting and counteracting resistance against TRAIL-based
therapeutics. Oncogene 32: 1341-50
Ding L, Yuan C, Wei F, Wang G, Zhang J, Bellail AC, Zhang Z, Olson JJ, Hao C (2011) Cisplatin
restores TRAIL apoptotic pathway in glioblastoma-derived stem cells through up-regulation of DR5
and down-regulation of c-FLIP. Cancer Invest 29: 511-20
Dong HP, Kleinberg L, Silins I, Florenes VA, Trope CG, Risberg B, Nesland JM, Davidson B (2008)
Death receptor expression is associated with poor response to chemotherapy and shorter survival in
metastatic ovarian carcinoma. Cancer 112: 84-93
Douillard JY, Cunningham D, Roth AD, Navarro M, James RD, Karasek P, Jandik P, Iveson T,
Carmichael J, Alakl M, Gruia G, Awad L, Rougier P (2000) Irinotecan combined with fluorouracil
compared with fluorouracil alone as first-line treatment for metastatic colorectal cancer: a
multicentre randomised trial. Lancet 355: 1041-7
Du C, Fang M, Li Y, Li L, Wang X (2000) Smac, a mitochondrial protein that promotes cytochrome cdependent
caspase activation by eliminating IAP inhibition. Cell 102: 33-42
Dubuisson a, Micheau O (2017) Antibodies and Derivatives Targeting DR4 and DR5 for Cancer
Therapy. Antibodies 6: 16
Hyršlová Vaculová 2018
32
Dufour F, Rattier T, Shirley S, Picarda G, Constantinescu AA, Morle A, Zakaria AB, Marcion G, Causse
S, Szegezdi E, Zajonc DM, Seigneuric R, Guichard G, Gharbi T, Picaud F, Herlem G, Garrido C,
Schneider P, Benedict CA, Micheau O (2017) N-glycosylation of mouse TRAIL-R and human
TRAIL-R1 enhances TRAIL-induced death. Cell Death Differ 24: 500-510
Earel JK, Jr., VanOosten RL, Griffith TS (2006) Histone deacetylase inhibitors modulate the sensitivity
of tumor necrosis factor-related apoptosis-inducing ligand-resistant bladder tumor cells. Cancer Res
66: 499-507
Efron PA, Chen MK, Iyengar M, Dai W, Nagaram A, Beierle EA (2006) Differential response of
neuroblastoma cells to TRAIL is independent of PI3K/AKT. J Pediatr Surg 41: 1072-80
Ehrhardt H, Fulda S, Schmid I, Hiscott J, Debatin KM, Jeremias I (2003) TRAIL induced survival and
proliferation in cancer cells resistant towards TRAIL-induced apoptosis mediated by NF-kappaB.
Oncogene 22: 3842-52
El-Zawahry A, McKillop J, Voelkel-Johnson C (2005) Doxorubicin increases the effectiveness of
Apo2L/TRAIL for tumor growth inhibition of prostate cancer xenografts. BMC Cancer 5: 2
El Fajoui Z, Toscano F, Jacquemin G, Abello J, Scoazec JY, Micheau O, Saurin JC (2011) Oxaliplatin
sensitizes human colon cancer cells to TRAIL through JNK-dependent phosphorylation of Bcl-xL.
Gastroenterology 141: 663-73
Elmore S (2007) Apoptosis: a review of programmed cell death. Toxicol Pathol 35: 495-516
Emery JG, McDonnell P, Burke MB, Deen KC, Lyn S, Silverman C, Dul E, Appelbaum ER, Eichman
C, DiPrinzio R, Dodds RA, James IE, Rosenberg M, Lee JC, Young PR (1998) Osteoprotegerin is a
receptor for the cytotoxic ligand TRAIL. J Biol Chem 273: 14363-7
Engels IH, Totzke G, Fischer U, Schulze-Osthoff K, Janicke RU (2005) Caspase-10 sensitizes breast
carcinoma cells to TRAIL-induced but not tumor necrosis factor-induced apoptosis in a caspase-3dependent
manner. Mol Cell Biol 25: 2808-18
Fakler M, Loeder S, Vogler M, Schneider K, Jeremias I, Debatin KM, Fulda S (2009) Small molecule
XIAP inhibitors cooperate with TRAIL to induce apoptosis in childhood acute leukemia cells and
overcome Bcl-2-mediated resistance. Blood 113: 1710-22
Falschlehner C, Emmerich CH, Gerlach B, Walczak H (2007) TRAIL signalling: decisions between life
and death. Int J Biochem Cell Biol 39: 1462-75
Favaloro B, Allocati N, Graziano V, Di Ilio C, De Laurenzi V (2012) Role of apoptosis in disease. Aging
(Albany NY) 4: 330-49
Finlay D, Vamos M, Gonzalez-Lopez M, Ardecky RJ, Ganji SR, Yuan H, Su Y, Cooley TR, Hauser
CT, Welsh K, Reed JC, Cosford ND, Vuori K (2014) Small-molecule IAP antagonists sensitize
cancer cells to TRAIL-induced apoptosis: roles of XIAP and cIAPs. Mol Cancer Ther 13: 5-15
Finnberg NK, Gokare P, Navaraj A, Lang Kuhs KA, Cerniglia G, Yagita H, Takeda K, Motoyama N,
El-Deiry WS (2016) Agonists of the TRAIL Death Receptor DR5 Sensitize Intestinal Stem Cells to
Chemotherapy-Induced Cell Death and Trigger Gastrointestinal Toxicity. Cancer Res 76: 700-12
Flusberg DA, Roux J, Spencer SL, Sorger PK (2013) Cells surviving fractional killing by TRAIL exhibit
transient but sustainable resistance and inflammatory phenotypes. Mol Biol Cell 24: 2186-200
Hyršlová Vaculová 2018
33
Fox JL, MacFarlane M (2016) Targeting cell death signalling in cancer: minimising 'Collateral damage'.
Br J Cancer 115: 5-11
Fulda S (2012) Histone deacetylase (HDAC) inhibitors and regulation of TRAIL-induced apoptosis.
Exp Cell Res 318: 1208-12
Fulda S (2013a) Targeting c-FLICE-like inhibitory protein (CFLAR) in cancer. Expert Opin Ther
Targets 17: 195-201
Fulda S (2013b) The dark side of TRAIL signaling. Cell Death Differ 20: 845-6
Fulda S (2014) Molecular pathways: targeting inhibitor of apoptosis proteins in cancer--from molecular
mechanism to therapeutic application. Clin Cancer Res 20: 289-95
Fulda S (2015) Targeting extrinsic apoptosis in cancer: Challenges and opportunities. Semin Cell Dev
Biol 39: 20-5
Fulda S (2017) Smac Mimetics to Therapeutically Target IAP Proteins in Cancer. Int Rev Cell Mol Biol
330: 157-169
Fulda S, Debatin KM (2006) Extrinsic versus intrinsic apoptosis pathways in anticancer chemotherapy.
Oncogene 25: 4798-811
Fulda S, Galluzzi L, Kroemer G (2010) Targeting mitochondria for cancer therapy. Nat Rev Drug Discov
9: 447-64
Fulda S, Meyer E, Debatin KM (2002a) Inhibition of TRAIL-induced apoptosis by Bcl-2
overexpression. Oncogene 21: 2283-94
Fulda S, Wick W, Weller M, Debatin KM (2002b) Smac agonists sensitize for Apo2L/TRAIL- or
anticancer drug-induced apoptosis and induce regression of malignant glioma in vivo. Nat Med 8:
808-15
Funcke JB, Zoller V, El Hay MA, Debatin KM, Wabitsch M, Fischer-Posovszky P (2015) TNF-related
apoptosis-inducing ligand promotes human preadipocyte proliferation via ERK1/2 activation.
FASEB J 29: 3065-75
Galligan L, Longley DB, McEwan M, Wilson TR, McLaughlin K, Johnston PG (2005) Chemotherapy
and TRAIL-mediated colon cancer cell death: the roles of p53, TRAIL receptors, and c-FLIP. Mol
Cancer Ther 4: 2026-36
Gallmeier E, Bader DC, Kriegl L, Berezowska S, Seeliger H, Goke B, Kirchner T, Bruns C, De Toni
EN (2013) Loss of TRAIL-receptors is a recurrent feature in pancreatic cancer and determines the
prognosis of patients with no nodal metastasis after surgery. PLoS One 8: e56760
Galluzzi L, Kepp O, Kroemer G (2012) Mitochondria: master regulators of danger signalling. Nat Rev
Mol Cell Biol 13: 780-8
Galluzzi L, Vitale I, Aaronson SA, Abrams JM, Adam D, Agostinis P, Alnemri ES, Altucci L, Amelio
I, Andrews DW, Annicchiarico-Petruzzelli M, Antonov AV, Arama E, Baehrecke EH, Barlev NA,
Bazan NG, Bernassola F, Bertrand MJM, Bianchi K, Blagosklonny MV, Blomgren K, Borner C,
Boya P, Brenner C, Campanella M, Candi E, Carmona-Gutierrez D, Cecconi F, Chan FK, Chandel
NS, Cheng EH, Chipuk JE, Cidlowski JA, Ciechanover A, Cohen GM, Conrad M, Cubillos-Ruiz JR,
Czabotar PE, D'Angiolella V, Dawson TM, Dawson VL, De Laurenzi V, De Maria R, Debatin KM,
DeBerardinis RJ, Deshmukh M, Di Daniele N, Di Virgilio F, Dixit VM, Dixon SJ, Duckett CS,
Hyršlová Vaculová 2018
34
Dynlacht BD, El-Deiry WS, Elrod JW, Fimia GM, Fulda S, Garcia-Saez AJ, Garg AD, Garrido C,
Gavathiotis E, Golstein P, Gottlieb E, Green DR, Greene LA, Gronemeyer H, Gross A, Hajnoczky
G, Hardwick JM, Harris IS, Hengartner MO, Hetz C, Ichijo H, Jaattela M, Joseph B, Jost PJ, Juin
PP, Kaiser WJ, Karin M, Kaufmann T, Kepp O, Kimchi A, Kitsis RN, Klionsky DJ, Knight RA,
Kumar S, Lee SW, Lemasters JJ, Levine B, Linkermann A, Lipton SA, Lockshin RA, Lopez-Otin
C, Lowe SW, Luedde T, Lugli E, MacFarlane M, Madeo F, Malewicz M, Malorni W, Manic G,
Marine JC, Martin SJ, Martinou JC, Medema JP, Mehlen P, Meier P, Melino S, Miao EA, Molkentin
JD, Moll UM, Munoz-Pinedo C, Nagata S, Nunez G, Oberst A, Oren M, Overholtzer M, Pagano M,
Panaretakis T, Pasparakis M, Penninger JM, Pereira DM, Pervaiz S, Peter ME, Piacentini M, Pinton
P, Prehn JHM, Puthalakath H, Rabinovich GA, Rehm M, Rizzuto R, Rodrigues CMP, Rubinsztein
DC, Rudel T, Ryan KM, Sayan E, Scorrano L, Shao F, Shi Y, Silke J, Simon HU, Sistigu A,
Stockwell BR, Strasser A, Szabadkai G, Tait SWG, Tang D, Tavernarakis N, Thorburn A, Tsujimoto
Y, Turk B, Vanden Berghe T, Vandenabeele P, Vander Heiden MG, Villunger A, Virgin HW,
Vousden KH, Vucic D, Wagner EF, Walczak H, Wallach D, Wang Y, Wells JA, Wood W, Yuan J,
Zakeri Z, Zhivotovsky B, Zitvogel L, Melino G, Kroemer G (2018) Molecular mechanisms of cell
death: recommendations of the Nomenclature Committee on Cell Death 2018. Cell Death Differ 25:
486-541
Ganapathy S, Chen Q, Singh KP, Shankar S, Srivastava RK (2010) Resveratrol enhances antitumor
activity of TRAIL in prostate cancer xenografts through activation of FOXO transcription factor.
PLoS One 5: e15627
Ganten TM, Haas TL, Sykora J, Stahl H, Sprick MR, Fas SC, Krueger A, Weigand MA, Grosse-Wilde
A, Stremmel W, Krammer PH, Walczak H (2004) Enhanced caspase-8 recruitment to and activation
at the DISC is critical for sensitisation of human hepatocellular carcinoma cells to TRAIL-induced
apoptosis by chemotherapeutic drugs. Cell Death Differ 11 Suppl 1: S86-96
Ganten TM, Koschny R, Sykora J, Schulze-Bergkamen H, Buchler P, Haas TL, Schader MB,
Untergasser A, Stremmel W, Walczak H (2006) Preclinical differentiation between apparently safe
and potentially hepatotoxic applications of TRAIL either alone or in combination with
chemotherapeutic drugs. Clin Cancer Res 12: 2640-6
Ganten TM, Sykora J, Koschny R, Batke E, Aulmann S, Mansmann U, Stremmel W, Sinn HP, Walczak
H (2009) Prognostic significance of tumour necrosis factor-related apoptosis-inducing ligand
(TRAIL) receptor expression in patients with breast cancer. J Mol Med (Berl) 87: 995-1007
Garcia MA, Carrasco E, Aguilera M, Alvarez P, Rivas C, Campos JM, Prados JC, Calleja MA, Esteban
M, Marchal JA, Aranega A (2011) The chemotherapeutic drug 5-fluorouracil promotes PKRmediated
apoptosis in a p53-independent manner in colon and breast cancer cells. PLoS One 6:
e23887
Giacchetti S, Perpoint B, Zidani R, Le Bail N, Faggiuolo R, Focan C, Chollet P, Llory JF, Letourneau
Y, Coudert B, Bertheaut-Cvitkovic F, Larregain-Fournier D, Le Rol A, Walter S, Adam R, Misset
JL, Levi F (2000) Phase III multicenter randomized trial of oxaliplatin added to chronomodulated
fluorouracil-leucovorin as first-line treatment of metastatic colorectal cancer. J Clin Oncol 18: 136-
47
Gibson CJ, Davids MS (2015) BCL-2 Antagonism to Target the Intrinsic Mitochondrial Pathway of
Apoptosis. Clin Cancer Res 21: 5021-9
Gibson SB, Oyer R, Spalding AC, Anderson SM, Johnson GL (2000) Increased expression of death
receptors 4 and 5 synergizes the apoptosis response to combined treatment with etoposide and
TRAIL. Mol Cell Biol 20: 205-12
Hyršlová Vaculová 2018
35
Gliniak B, Le T (1999) Tumor necrosis factor-related apoptosis-inducing ligand's antitumor activity in
vivo is enhanced by the chemotherapeutic agent CPT-11. Cancer Res 59: 6153-8
Goncharenko-Khaider N, Lane D, Matte I, Rancourt C, Piche A (2010) The inhibition of Bid expression
by Akt leads to resistance to TRAIL-induced apoptosis in ovarian cancer cells. Oncogene 29: 5523-
36
Griffith TS, Rauch CT, Smolak PJ, Waugh JY, Boiani N, Lynch DH, Smith CA, Goodwin RG, Kubin
MZ (1999) Functional analysis of TRAIL receptors using monoclonal antibodies. J Immunol 162:
2597-605
Grootjans S, Vanden Berghe T, Vandenabeele P (2017) Initiation and execution mechanisms of
necroptosis: an overview. Cell Death Differ 24: 1184-1195
Grosse-Wilde A, Voloshanenko O, Bailey SL, Longton GM, Schaefer U, Csernok AI, Schutz G, Greiner
EF, Kemp CJ, Walczak H (2008) TRAIL-R deficiency in mice enhances lymph node metastasis
without affecting primary tumor development. J Clin Invest 118: 100-10
Grotzer MA, Eggert A, Zuzak TJ, Janss AJ, Marwaha S, Wiewrodt BR, Ikegaki N, Brodeur GM, Phillips
PC (2000) Resistance to TRAIL-induced apoptosis in primitive neuroectodermal brain tumor cells
correlates with a loss of caspase-8 expression. Oncogene 19: 4604-10
Guimaraes PPG, Gaglione S, Sewastianik T, Carrasco RD, Langer R, Mitchell MJ (2018) Nanoparticles
for Immune Cytokine TRAIL-Based Cancer Therapy. ACS Nano 12: 912-931
Guzi TJ, Paruch K, Dwyer MP, Labroli M, Shanahan F, Davis N, Taricani L, Wiswell D, Seghezzi W,
Penaflor E, Bhagwat B, Wang W, Gu D, Hsieh Y, Lee S, Liu M, Parry D (2011) Targeting the
replication checkpoint using SCH 900776, a potent and functionally selective CHK1 inhibitor
identified via high content screening. Mol Cancer Ther 10: 591-602
Hanahan D, Weinberg RA (2000) The hallmarks of cancer. Cell 100: 57-70
Hanahan D, Weinberg RA (2011) Hallmarks of cancer: the next generation. Cell 144: 646-74
Harper N, Farrow SN, Kaptein A, Cohen GM, MacFarlane M (2001) Modulation of tumor necrosis
factor apoptosis-inducing ligand- induced NF-kappa B activation by inhibition of apical caspases. J
Biol Chem 276: 34743-52
Hartmann D, Lucks J, Fuchs S, Schiffmann S, Schreiber Y, Ferreiros N, Merkens J, Marschalek R,
Geisslinger G, Grosch S (2012) Long chain ceramides and very long chain ceramides have opposite
effects on human breast and colon cancer cell growth. Int J Biochem Cell Biol 44: 620-8
Hartwig T, Montinaro A, von Karstedt S, Sevko A, Surinova S, Chakravarthy A, Taraborrelli L, Draber
P, Lafont E, Arce Vargas F, El-Bahrawy MA, Quezada SA, Walczak H (2017) The TRAIL-Induced
Cancer Secretome Promotes a Tumor-Supportive Immune Microenvironment via CCR2. Mol Cell
65: 730-742 e5
Haselmann V, Kurz A, Bertsch U, Hubner S, Olempska-Muller M, Fritsch J, Hasler R, Pickl A, Fritsche
H, Annewanter F, Engler C, Fleig B, Bernt A, Roder C, Schmidt H, Gelhaus C, Hauser C, Egberts
JH, Heneweer C, Rohde AM, Boger C, Knippschild U, Rocken C, Adam D, Walczak H, Schutze S,
Janssen O, Wulczyn FG, Wajant H, Kalthoff H, Trauzold A (2014) Nuclear death receptor TRAILR2
inhibits maturation of let-7 and promotes proliferation of pancreatic and other tumor cells.
Gastroenterology 146: 278-90
Hyršlová Vaculová 2018
36
Hellwig CT, Rehm M (2012) TRAIL signaling and synergy mechanisms used in TRAIL-based
combination therapies. Mol Cancer Ther 11: 3-13
Herudkova J, Paruch K, Khirsariya P, Soucek K, Krkoska M, Vondalova Blanarova O, Sova P,
Kozubik A, Hyrslova Vaculova A (2017) Chk1 Inhibitor SCH900776 Effectively Potentiates
the Cytotoxic Effects of Platinum-Based Chemotherapeutic Drugs in Human Colon Cancer
Cells. Neoplasia 19: 830-841
Hinz S, Trauzold A, Boenicke L, Sandberg C, Beckmann S, Bayer E, Walczak H, Kalthoff H,
Ungefroren H (2000) Bcl-XL protects pancreatic adenocarcinoma cells against CD95- and TRAILreceptor-mediated
apoptosis. Oncogene 19: 5477-86
Hofmanova J, Ciganek M, Slavik J, Kozubik A, Stixova L, Vaculova A, Dusek L, Machala M
(2012) Lipid alterations in human colon epithelial cells induced to differentiation and/or
apoptosis by butyrate and polyunsaturated fatty acids. J Nutr Biochem 23: 539-48
Hofmanova J, Slavik J, Ovesna P, Tylichova Z, Vondracek J, Strakova N, Vaculova AH, Ciganek
M, Kozubik A, Knopfova L, Smarda J, Machala M (2017) Dietary fatty acids specifically
modulate phospholipid pattern in colon cells with distinct differentiation capacities. Eur J Nutr
56: 1493-1508
Hofmanova J, Strakova N, Vaculova AH, Tylichova Z, Safarikova B, Skender B, Kozubik A
(2014) Interaction of dietary fatty acids with tumour necrosis factor family cytokines during
colon inflammation and cancer. Mediators Inflamm 2014: 848632
Hofmanova J, Vaculova A, Hyzd'alova M, Kozubik A (2008) Response of normal and colon cancer
epithelial cells to TNF-family apoptotic inducers. Oncol Rep 19: 567-73
Hofmanova J, Vaculova A, Kozubik A (2005) Polyunsaturated fatty acids sensitize human colon
adenocarcinoma HT-29 cells to death receptor-mediated apoptosis. Cancer Lett 218: 33-41
Hoogwater FJ, Nijkamp MW, Smakman N, Steller EJ, Emmink BL, Westendorp BF, Raats DA, Sprick
MR, Schaefer U, Van Houdt WJ, De Bruijn MT, Schackmann RC, Derksen PW, Medema JP,
Walczak H, Borel Rinkes IH, Kranenburg O (2010) Oncogenic K-Ras turns death receptors into
metastasis-promoting receptors in human and mouse colorectal cancer cells. Gastroenterology 138:
2357-67
Hopkins-Donaldson S, Bodmer JL, Bourloud KB, Brognara CB, Tschopp J, Gross N (2000) Loss of
caspase-8 expression in highly malignant human neuroblastoma cells correlates with resistance to
tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis. Cancer Res 60: 4315-9
Hopkins-Donaldson S, Ziegler A, Kurtz S, Bigosch C, Kandioler D, Ludwig C, Zangemeister-Wittke
U, Stahel R (2003) Silencing of death receptor and caspase-8 expression in small cell lung carcinoma
cell lines and tumors by DNA methylation. Cell Death Differ 10: 356-64
Horak P, Pils D, Haller G, Pribill I, Roessler M, Tomek S, Horvat R, Zeillinger R, Zielinski C, Krainer
M (2005) Contribution of epigenetic silencing of tumor necrosis factor-related apoptosis inducing
ligand receptor 1 (DR4) to TRAIL resistance and ovarian cancer. Mol Cancer Res 3: 335-43
Horn S, Hughes MA, Schilling R, Sticht C, Tenev T, Ploesser M, Meier P, Sprick MR, MacFarlane M,
Leverkus M (2017) Caspase-10 Negatively Regulates Caspase-8-Mediated Cell Death, Switching
the Response to CD95L in Favor of NF-kappaB Activation and Cell Survival. Cell Rep 19: 785-797
Horova V, Hradilova N, Jelinkova I, Koc M, Svadlenka J, Brazina J, Klima M, Slavik J, Hyrslova
Vaculova A, Andera L (2013) Inhibition of vacuolar ATPase attenuates the TRAIL-induced
Hyršlová Vaculová 2018
37
activation of caspase-8 and modulates the trafficking of TRAIL receptosomes. FEBS J 280:
3436-50
Horvath V, Blanarova O, Svihalkova-Sindlerova L, Soucek K, Hofmanova J, Sova P, Kroutil A,
Fedorocko P, Kozubik A (2006) Platinum(IV) complex with adamantylamine overcomes intrinsic
resistance to cisplatin in ovarian cancer cells. Gynecol Oncol 102: 32-40
Horvath V, Soucek K, Svihalkova-Sindlerova L, Vondracek J, Blanarova O, Hofmanova J, Sova P,
Kozubik A (2007) Different cell cycle modulation following treatment of human ovarian carcinoma
cells with a new platinum(IV) complex vs cisplatin. Invest New Drugs 25: 435-43
Huang S, Sinicrope FA (2008) BH3 mimetic ABT-737 potentiates TRAIL-mediated apoptotic signaling
by unsequestering Bim and Bak in human pancreatic cancer cells. Cancer Res 68: 2944-51
Hughes MA, Powley IR, Jukes-Jones R, Horn S, Feoktistova M, Fairall L, Schwabe JW, Leverkus M,
Cain K, MacFarlane M (2016) Co-operative and Hierarchical Binding of c-FLIP and Caspase-8: A
Unified Model Defines How c-FLIP Isoforms Differentially Control Cell Fate. Mol Cell 61: 834-49
Humphreys L, Espona-Fiedler M, Longley DB (2018) FLIP as a therapeutic target in cancer. FEBS J,
14523
Hunter TB, Manimala NJ, Luddy KA, Catlin T, Antonia SJ (2011) Paclitaxel and TRAIL synergize to
kill paclitaxel-resistant small cell lung cancer cells through a caspase-independent mechanism
mediated through AIF. Anticancer Res 31: 3193-204
Huntoon CJ, Flatten KS, Wahner Hendrickson AE, Huehls AM, Sutor SL, Kaufmann SH, Karnitz LM
(2013) ATR inhibition broadly sensitizes ovarian cancer cells to chemotherapy independent of
BRCA status. Cancer Res 73: 3683-91
Hylander BL, Pitoniak R, Penetrante RB, Gibbs JF, Oktay D, Cheng J, Repasky EA (2005) The antitumor
effect of Apo2L/TRAIL on patient pancreatic adenocarcinomas grown as xenografts in SCID
mice. J Transl Med 3: 22
Chen X, Thakkar H, Tyan F, Gim S, Robinson H, Lee C, Pandey SK, Nwokorie C, Onwudiwe N,
Srivastava RK (2001) Constitutively active Akt is an important regulator of TRAIL sensitivity in
prostate cancer. Oncogene 20: 6073-83
Chinnaiyan AM, Prasad U, Shankar S, Hamstra DA, Shanaiah M, Chenevert TL, Ross BD, Rehemtulla
A (2000) Combined effect of tumor necrosis factor-related apoptosis-inducing ligand and ionizing
radiation in breast cancer therapy. Proc Natl Acad Sci U S A 97: 1754-9
Chipuk JE, Green DR (2008) How do BCL-2 proteins induce mitochondrial outer membrane
permeabilization? Trends Cell Biol 18: 157-64
Inoue S, Browne G, Melino G, Cohen GM (2009) Ordering of caspases in cells undergoing apoptosis
by the intrinsic pathway. Cell Death Differ 16: 1053-61
Inoue S, MacFarlane M, Harper N, Wheat LM, Dyer MJ, Cohen GM (2004) Histone deacetylase
inhibitors potentiate TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in lymphoid
malignancies. Cell Death Differ 11 Suppl 2: S193-206
Ishimura N, Isomoto H, Bronk SF, Gores GJ (2006) Trail induces cell migration and invasion in
apoptosis-resistant cholangiocarcinoma cells. Am J Physiol Gastrointest Liver Physiol 290: G129-
36
Hyršlová Vaculová 2018
38
Jacquemin G, Granci V, Gallouet AS, Lalaoui N, Morle A, Iessi E, Morizot A, Garrido C, Guillaudeux
T, Micheau O (2012) Quercetin-mediated Mcl-1 and survivin downregulation restores TRAILinduced
apoptosis in non-Hodgkin's lymphoma B cells. Haematologica 97: 38-46
Jakobsen CH, Storvold GL, Bremseth H, Follestad T, Sand K, Mack M, Olsen KS, Lundemo AG,
Iversen JG, Krokan HE, Schonberg SA (2008) DHA induces ER stress and growth arrest in human
colon cancer cells: associations with cholesterol and calcium homeostasis. J Lipid Res 49: 2089-100
Jalving M, Heijink DM, Koornstra JJ, Boersma-van Ek W, Zwart N, Wesseling J, Sluiter WJ, de Vries
EG, Kleibeuker JH, de Jong S (2014) Regulation of TRAIL receptor expression by beta-catenin in
colorectal tumours. Carcinogenesis 35: 1092-9
Jaworska D, Szliszka E (2017) Targeting Apoptotic Activity Against Prostate Cancer Stem Cells. Int J
Mol Sci 18, e 1648
Jayasooriya RG, Choi YH, Hyun JW, Kim GY (2014) Camptothecin sensitizes human hepatoma Hep3B
cells to TRAIL-mediated apoptosis via ROS-dependent death receptor 5 upregulation with the
involvement of MAPKs. Environ Toxicol Pharmacol 38: 959-67
Jelinkova I, Safarikova B, Vondalova Blanarova O, Skender B, Hofmanova J, Sova P, Moyer MP,
Kozubik A, Kolar Z, Ehrmann J, Hyrslova Vaculova A (2014) Platinum(IV) complex LA-12
exerts higher ability than cisplatin to enhance TRAIL-induced cancer cell apoptosis via
stimulation of mitochondrial pathway. Biochem Pharmacol 92: 415-24
Jennewein C, Karl S, Baumann B, Micheau O, Debatin KM, Fulda S (2011) Identification of a novel
pro-apoptotic role of NF-kappaB in the regulation of TRAIL- and CD95-mediated apoptosis of
glioblastoma cells. Oncogene 31: 1468-74
Jeremias I, Kupatt C, Baumann B, Herr I, Wirth T, Debatin KM (1998) Inhibition of nuclear factor
kappaB activation attenuates apoptosis resistance in lymphoid cells. Blood 91: 4624-31
Jin Z, Li Y, Pitti R, Lawrence D, Pham VC, Lill JR, Ashkenazi A (2009) Cullin3-based
polyubiquitination and p62-dependent aggregation of caspase-8 mediate extrinsic apoptosis
signaling. Cell 137: 721-35
Jin Z, McDonald ER, 3rd, Dicker DT, El-Deiry WS (2004) Deficient tumor necrosis factor-related
apoptosis-inducing ligand (TRAIL) death receptor transport to the cell surface in human colon cancer
cells selected for resistance to TRAIL-induced apoptosis. J Biol Chem 279: 35829-39
Jo M, Kim TH, Seol DW, Esplen JE, Dorko K, Billiar TR, Strom SC (2000) Apoptosis induced in
normal human hepatocytes by tumor necrosis factor-related apoptosis-inducing ligand. Nat Med 6:
564-7
Johnston PG, Lenz HJ, Leichman CG, Danenberg KD, Allegra CJ, Danenberg PV, Leichman L (1995)
Thymidylate synthase gene and protein expression correlate and are associated with response to 5fluorouracil
in human colorectal and gastric tumors. Cancer Res 55: 1407-12
Johnstone RW, Frew AJ, Smyth MJ (2008) The TRAIL apoptotic pathway in cancer onset, progression
and therapy. Nat Rev Cancer 8: 782-98
Joseph B, Ekedahl J, Sirzen F, Lewensohn R, Zhivotovsky B (1999) Differences in expression of procaspases
in small cell and non-small cell lung carcinoma. Biochem Biophys Res Commun 262: 381-
7
Hyršlová Vaculová 2018
39
Jouan-Lanhouet S, Arshad MI, Piquet-Pellorce C, Martin-Chouly C, Le Moigne-Muller G, Van
Herreweghe F, Takahashi N, Sergent O, Lagadic-Gossmann D, Vandenabeele P, Samson M,
Dimanche-Boitrel MT (2012) TRAIL induces necroptosis involving RIPK1/RIPK3-dependent
PARP-1 activation. Cell Death Differ 19: 2003-14
Kale J, Osterlund EJ, Andrews DW (2018) BCL-2 family proteins: changing partners in the dance
towards death. Cell Death Differ 25: 65-80
Kaminskyy VO, Surova OV, Vaculova A, Zhivotovsky B (2011) Combined inhibition of DNA
methyltransferase and histone deacetylase restores caspase-8 expression and sensitizes SCLC
cells to TRAIL. Carcinogenesis 32: 1450-8
Kandasamy K, Srinivasula SM, Alnemri ES, Thompson CB, Korsmeyer SJ, Bryant JL, Srivastava RK
(2003) Involvement of proapoptotic molecules Bax and Bak in tumor necrosis factor-related
apoptosis-inducing ligand (TRAIL)-induced mitochondrial disruption and apoptosis: differential
regulation of cytochrome c and Smac/DIABLO release. Cancer Res 63: 1712-21
Kang J, Bu J, Hao Y, Chen F (2005) Subtoxic concentration of doxorubicin enhances TRAIL-induced
apoptosis in human prostate cancer cell line LNCaP. Prostate Cancer Prostatic Dis 8: 274-9
Karacay B, Sanlioglu S, Griffith TS, Sandler A, Bonthius DJ (2004) Inhibition of the NF-kappaB
pathway enhances TRAIL-mediated apoptosis in neuroblastoma cells. Cancer Gene Ther 11: 681-
90
Kelley RF, Totpal K, Lindstrom SH, Mathieu M, Billeci K, Deforge L, Pai R, Hymowitz SG, Ashkenazi
A (2005) Receptor-selective mutants of apoptosis-inducing ligand 2/tumor necrosis factor-related
apoptosis-inducing ligand reveal a greater contribution of death receptor (DR) 5 than DR4 to
apoptosis signaling. J Biol Chem 280: 2205-12
Kerr JF, Wyllie AH, Currie AR (1972) Apoptosis: a basic biological phenomenon with wide-ranging
implications in tissue kinetics. Br J Cancer 26: 239-57
Kim HS, Lee JW, Soung YH, Park WS, Kim SY, Lee JH, Park JY, Cho YG, Kim CJ, Jeong SW, Nam
SW, Kim SH, Lee JY, Yoo NJ, Lee SH (2003) Inactivating mutations of caspase-8 gene in colorectal
carcinomas. Gastroenterology 125: 708-15
Kim MR, Lee JY, Park MT, Chun YJ, Jang YJ, Kang CM, Kim HS, Cho CK, Lee YS, Jeong HY, Lee
SJ (2001) Ionizing radiation can overcome resistance to TRAIL in TRAIL-resistant cancer cells.
FEBS Lett 505: 179-84
Kim YH, Park JW, Lee JY, Kwon TK (2004) Sodium butyrate sensitizes TRAIL-mediated apoptosis by
induction of transcription from the DR5 gene promoter through Sp1 sites in colon cancer cells.
Carcinogenesis 25: 1813-20
Kischkel FC, Lawrence DA, Tinel A, LeBlanc H, Virmani A, Schow P, Gazdar A, Blenis J, Arnott D,
Ashkenazi A (2001) Death receptor recruitment of endogenous caspase-10 and apoptosis initiation
in the absence of caspase-8. J Biol Chem 276: 46639-46
Koci L, Hyzd'alova M, Vaculova A, Hofmanova J, Kozubik A (2011) Detachment-mediated
resistance to TRAIL-induced apoptosis is associated with stimulation of the PI3K/Akt pathway
in fetal and adenocarcinoma epithelial colon cells. Cytokine 55: 34-9
Kohlhaas SL, Craxton A, Sun XM, Pinkoski MJ, Cohen GM (2007) Receptor-mediated endocytosis is
not required for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis.
J Biol Chem 282: 12831-41
Hyršlová Vaculová 2018
40
Kojima Y, Nakayama M, Nishina T, Nakano H, Koyanagi M, Takeda K, Okumura K, Yagita H (2011)
Importin beta1 protein-mediated nuclear localization of death receptor 5 (DR5) limits DR5/tumor
necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-induced cell death of human tumor
cells. J Biol Chem 286: 43383-93
Koornstra JJ, Kleibeuker JH, van Geelen CM, Rijcken FE, Hollema H, de Vries EG, de Jong S (2003)
Expression of TRAIL (TNF-related apoptosis-inducing ligand) and its receptors in normal colonic
mucosa, adenomas, and carcinomas. J Pathol 200: 327-35
Koschny R, Ganten TM, Sykora J, Haas TL, Sprick MR, Kolb A, Stremmel W, Walczak H (2007c)
TRAIL/bortezomib cotreatment is potentially hepatotoxic but induces cancer-specific apoptosis
within a therapeutic window. Hepatology 45: 649-58
Koschny R, Holland H, Sykora J, Haas TL, Sprick MR, Ganten TM, Krupp W, Bauer M, Ahnert P,
Meixensberger J, Walczak H (2007a) Bortezomib sensitizes primary human astrocytoma cells of
WHO grades I to IV for tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis.
Clin Cancer Res 13: 3403-12
Koschny R, Walczak H, Ganten TM (2007b) The promise of TRAIL--potential and risks of a novel
anticancer therapy. J Mol Med (Berl) 85: 923-35
Kozubik A, Horvath V, Svihalkova-Sindlerova L, Soucek K, Hofmanova J, Sova P, Kroutil A, Zak F,
Mistr A, Turanek J (2005) High effectiveness of platinum(IV) complex with adamantylamine in
overcoming resistance to cisplatin and suppressing proliferation of ovarian cancer cells in vitro.
Biochem Pharmacol 69: 373-83
Kozubik A, Vaculova A, Soucek K, Vondracek J, Turanek J, Hofmanova J (2008) Novel
Anticancer Platinum(IV) Complexes with Adamantylamine: Their Efficiency and Innovative
Chemotherapy Strategies Modifying Lipid Metabolism. Met Based Drugs 2008: 417897
Kretz AL, von Karstedt S, Hillenbrand A, Henne-Bruns D, Knippschild U, Trauzold A, Lemke J (2018)
Should We Keep Walking along the Trail for Pancreatic Cancer Treatment? Revisiting TNF-Related
Apoptosis-Inducing Ligand for Anticancer Therapy. Cancers (Basel) 10: 77
Kriegl L, Jung A, Horst D, Rizzani A, Jackstadt R, Hermeking H, Gallmeier E, Gerbes AL, Kirchner T,
Goke B, De Toni EN (2012) Microsatellite instability, KRAS mutations and cellular distribution of
TRAIL-receptors in early stage colorectal cancer. PLoS One 7: e51654
Kvardova V, Hrstka R, Walerych D, Muller P, Matoulkova E, Hruskova V, Stelclova D, Sova P,
Vojtesek B (2010) The new platinum(IV) derivative LA-12 shows stronger inhibitory effect on
Hsp90 function compared to cisplatin. Mol Cancer 9: 147
Lacour S, Micheau O, Hammann A, Drouineaud V, Tschopp J, Solary E, Dimanche-Boitrel MT (2003)
Chemotherapy enhances TNF-related apoptosis-inducing ligand DISC assembly in HT29 human
colon cancer cells. Oncogene 22: 1807-16
Lafont E, Hartwig T, Walczak H (2018) Paving TRAIL's Path with Ubiquitin. Trends Biochem Sci 43:
44-60
Lafont E, Kantari-Mimoun C, Draber P, De Miguel D, Hartwig T, Reichert M, Kupka S, Shimizu Y,
Taraborrelli L, Spit M, Sprick MR, Walczak H (2017) The linear ubiquitin chain assembly complex
regulates TRAIL-induced gene activation and cell death. EMBO J 36: 1147-1166
Hyršlová Vaculová 2018
41
Lalaoui N, Morle A, Merino D, Jacquemin G, Iessi E, Morizot A, Shirley S, Robert B, Solary E, Garrido
C, Micheau O (2001) TRAIL-R4 promotes tumor growth and resistance to apoptosis in cervical
carcinoma HeLa cells through AKT. PLoS One 6: e19679
Lalaoui N, Morle A, Merino D, Jacquemin G, Iessi E, Morizot A, Shirley S, Robert B, Solary E, Garrido
C, Micheau O (2011) TRAIL-R4 promotes tumor growth and resistance to apoptosis in cervical
carcinoma HeLa cells through AKT. PLoS One 6: e19679
Lane D, Cartier A, Rancourt C, Piche A (2008) Cell detachment modulates TRAIL resistance in ovarian
cancer cells by downregulating the phosphatidylinositol 3-kinase/Akt pathway. Int J Gynecol Cancer
18: 670-6
Laukova J, Kozubik A, Hofmanova J, Nekvindova J, Sova P, Moyer MP, Ehrmann J, Hyrslova
Vaculova A (2015) Loss of PTEN Facilitates Rosiglitazone-Mediated Enhancement of
Platinum(IV) Complex LA-12-Induced Apoptosis in Colon Cancer Cells. PLoS One 10:
e0141020
Lawrence D, Shahrokh Z, Marsters S, Achilles K, Shih D, Mounho B, Hillan K, Totpal K, DeForge L,
Schow P, Hooley J, Sherwood S, Pai R, Leung S, Khan L, Gliniak B, Bussiere J, Smith CA, Strom
SS, Kelley S, Fox JA, Thomas D, Ashkenazi A (2001) Differential hepatocyte toxicity of
recombinant Apo2L/TRAIL versions. Nat Med 7: 383-5
LeBlanc H, Lawrence D, Varfolomeev E, Totpal K, Morlan J, Schow P, Fong S, Schwall R, Sinicropi
D, Ashkenazi A (2002) Tumor-cell resistance to death receptor--induced apoptosis through
mutational inactivation of the proapoptotic Bcl-2 homolog Bax. Nat Med 8: 274-81
Lecis D, Drago C, Manzoni L, Seneci P, Scolastico C, Mastrangelo E, Bolognesi M, Anichini A,
Kashkar H, Walczak H, Delia D (2010) Novel SMAC-mimetics synergistically stimulate melanoma
cell death in combination with TRAIL and Bortezomib. Br J Cancer 102: 1707-16
Lee JY, Sim TB, Lee JE, Na HK (2017) Chemopreventive and Chemotherapeutic Effects of Fish Oil
derived Omega-3 Polyunsaturated Fatty Acids on Colon Carcinogenesis. Clin Nutr Res 6: 147-160
Leithner K, Stacher E, Wurm R, Ploner F, Quehenberger F, Wohlkoenig C, Balint Z, Polachova J,
Olschewski A, Samonigg H, Popper HH, Olschewski H (2009) Nuclear and cytoplasmic death
receptor 5 as prognostic factors in patients with non-small cell lung cancer treated with
chemotherapy. Lung Cancer 65: 98-104
Lemke J, Noack A, Adam D, Tchikov V, Bertsch U, Roder C, Schutze S, Wajant H, Kalthoff H,
Trauzold A (2010) TRAIL signaling is mediated by DR4 in pancreatic tumor cells despite the
expression of functional DR5. J Mol Med (Berl) 88: 729-40
Lemke J, von Karstedt S, Zinngrebe J, Walczak H (2014a) Getting TRAIL back on track for cancer
therapy. Cell Death Differ 21: 1350-64
Letai A (2015) Cell Death and Cancer Therapy: Don't Forget to Kill the Cancer Cell! Clin Cancer Res
21: 5015-20
Letai A (2017) Functional precision cancer medicine-moving beyond pure genomics. Nat Med 23: 1028-
1035
Leverkus M, Sprick MR, Wachter T, Denk A, Brocker EB, Walczak H, Neumann M (2003) TRAILinduced
apoptosis and gene induction in HaCaT keratinocytes: differential contribution of TRAIL
receptors 1 and 2. J Invest Dermatol 121: 149-55
Hyršlová Vaculová 2018
42
Li L, Thomas RM, Suzuki H, De Brabander JK, Wang X, Harran PG (2004) A small molecule Smac
mimic potentiates TRAIL- and TNFalpha-mediated cell death. Science 305: 1471-4
Li L, Wen XZ, Bu ZD, Cheng XJ, Xing XF, Wang XH, Zhang LH, Guo T, Du H, Hu Y, Fan B, Ji JF
(2016) Paclitaxel enhances tumoricidal potential of TRAIL via inhibition of MAPK in resistant
gastric cancer cells. Oncol Rep 35: 3009-17
Lippa MS, Strockbine LD, Le TT, Branstetter DG, Strathdee CA, Holland PM (2007) Expression of
anti-apoptotic factors modulates Apo2L/TRAIL resistance in colon carcinoma cells. Apoptosis 12:
1465-78
Liu J, Qu X, Xu L, Zhang Y, Qu J, Hou K, Liu Y (2010) Phosphoinositide 3-kinase/Akt and nuclear
factor kappaB pathways are involved in tumor necrosis factor-related apoptosis-inducing ligand
resistance in human gastric cancer cells. Mol Med Rep 3: 491-6
Liu W, Bodle E, Chen JY, Gao M, Rosen GD, Broaddus VC (2001) Tumor necrosis factor-related
apoptosis-inducing ligand and chemotherapy cooperate to induce apoptosis in mesothelioma cell
lines. Am J Respir Cell Mol Biol 25: 111-8
Liu X, Kim CN, Yang J, Jemmerson R, Wang X (1996) Induction of apoptotic program in cell-free
extracts: requirement for dATP and cytochrome c. Cell 86: 147-57
Lockshin RA, Zakeri Z (2007) Cell death in health and disease. J Cell Mol Med 11: 1214-24
Longley DB, Boyer J, Allen WL, Latif T, Ferguson PR, Maxwell PJ, McDermott U, Lynch M, Harkin
DP, Johnston PG (2002) The role of thymidylate synthase induction in modulating p53-regulated
gene expression in response to 5-fluorouracil and antifolates. Cancer Res 62: 2644-9
Longley DB, Harkin DP, Johnston PG (2003) 5-fluorouracil: mechanisms of action and clinical
strategies. Nat Rev Cancer 3: 330-8
Longley DB, Wilson TR, McEwan M, Allen WL, McDermott U, Galligan L, Johnston PG (2006) cFLIP
inhibits chemotherapy-induced colorectal cancer cell death. Oncogene 25: 838-48
MacFarlane M, Ahmad M, Srinivasula SM, Fernandes-Alnemri T, Cohen GM, Alnemri ES (1997)
Identification and molecular cloning of two novel receptors for the cytotoxic ligand TRAIL. J Biol
Chem 272: 25417-20
MacFarlane M, Harper N, Snowden RT, Dyer MJ, Barnett GA, Pringle JH, Cohen GM (2002)
Mechanisms of resistance to TRAIL-induced apoptosis in primary B cell chronic lymphocytic
leukaemia. Oncogene 21: 6809-18
MacFarlane M, Inoue S, Kohlhaas SL, Majid A, Harper N, Kennedy DB, Dyer MJ, Cohen GM (2005a)
Chronic lymphocytic leukemic cells exhibit apoptotic signaling via TRAIL-R1. Cell Death Differ
12: 773-82
MacFarlane M, Kohlhaas SL, Sutcliffe MJ, Dyer MJ, Cohen GM (2005) TRAIL receptor-selective
mutants signal to apoptosis via TRAIL-R1 in primary lymphoid malignancies. Cancer Res 65:
11265-70
Mahalingam D, Szegezdi E, Keane M, de Jong S, Samali A (2009) TRAIL receptor signalling and
modulation: Are we on the right TRAIL? Cancer Treat Rev 35: 280-8
Malhi H, Gores GJ (2006) TRAIL resistance results in cancer progression: a TRAIL to perdition?
Oncogene 25: 7333-5
Hyršlová Vaculová 2018
43
Marconi M, Ascione B, Ciarlo L, Vona R, Garofalo T, Sorice M, Gianni AM, Locatelli SL, Carlo-Stella
C, Malorni W, Matarrese P (2013) Constitutive localization of DR4 in lipid rafts is mandatory for
TRAIL-induced apoptosis in B-cell hematologic malignancies. Cell Death Dis 4: e863
Marini P, Schmid A, Jendrossek V, Faltin H, Daniel PT, Budach W, Belka C (2005) Irradiation
specifically sensitises solid tumour cell lines to TRAIL mediated apoptosis. BMC Cancer 5: 5
Marsters SA, Sheridan JP, Pitti RM, Huang A, Skubatch M, Baldwin D, Yuan J, Gurney A, Goddard
AD, Godowski P, Ashkenazi A (1997) A novel receptor for Apo2L/TRAIL contains a truncated
death domain. Curr Biol 7: 1003-6
Martinez-Ruiz G, Maldonado V, Ceballos-Cancino G, Grajeda JP, Melendez-Zajgla J (2008) Role of
Smac/DIABLO in cancer progression. J Exp Clin Cancer Res 27: 48
McCarthy MM, Sznol M, DiVito KA, Camp RL, Rimm DL, Kluger HM (2005) Evaluating the
expression and prognostic value of TRAIL-R1 and TRAIL-R2 in breast cancer. Clin Cancer Res 11:
5188-94
McDonald ER, 3rd, Chui PC, Martelli PF, Dicker DT, El-Deiry WS (2001) Death domain mutagenesis
of KILLER/DR5 reveals residues critical for apoptotic signaling. J Biol Chem 276: 14939-45
Melino G, Vaux D (2010) Cell death. Wiley-Blackwell, Oxford, ISBN: 978-0-470-71573-4
Meng XW, Lee SH, Dai H, Loegering D, Yu C, Flatten K, Schneider P, Dai NT, Kumar SK, Smith BD,
Karp JE, Adjei AA, Kaufmann SH (2007) Mcl-1 as a buffer for proapoptotic Bcl-2 family members
during TRAIL-induced apoptosis: a mechanistic basis for sorafenib (Bay 43-9006)-induced TRAIL
sensitization. J Biol Chem 282: 29831-46
Merino D, Lalaoui N, Morizot A, Schneider P, Solary E, Micheau O (2006) Differential inhibition of
TRAIL-mediated DR5-DISC formation by decoy receptors 1 and 2. Mol Cell Biol 26: 7046-55
Mert U, Sanlioglu AD (2017) Intracellular localization of DR5 and related regulatory pathways as a
mechanism of resistance to TRAIL in cancer. Cell Mol Life Sci 74: 245-255
Meurette O, Huc L, Rebillard A, Le Moigne G, Lagadic-Gossmann D, Dimanche-Boitrel MT (2005)
TRAIL (TNF-related apoptosis-inducing ligand) induces necrosis-like cell death in tumor cells at
acidic extracellular pH. Ann N Y Acad Sci 1056: 379-87
Meurette O, Rebillard A, Huc L, Le Moigne G, Merino D, Micheau O, Lagadic-Gossmann D,
Dimanche-Boitrel MT (2007) TRAIL induces receptor-interacting protein 1-dependent and caspasedependent
necrosis-like cell death under acidic extracellular conditions. Cancer Res 67: 218-26
Meyers M, Hwang A, Wagner MW, Boothman DA (2004) Role of DNA mismatch repair in apoptotic
responses to therapeutic agents. Environ Mol Mutagen 44: 249-64
Mizutani Y, Nakanishi H, Yoshida O, Fukushima M, Bonavida B, Miki T (2002) Potentiation of the
sensitivity of renal cell carcinoma cells to TRAIL-mediated apoptosis by subtoxic concentrations of
5-fluorouracil. Eur J Cancer 38: 167-76
Mohamed MS, Bishr MK, Almutairi FM, Ali AG (2017) Inhibitors of apoptosis: clinical implications
in cancer. Apoptosis 22: 1487-1509
Hyršlová Vaculová 2018
44
Montano R, Chung I, Garner KM, Parry D, Eastman A (2012) Preclinical development of the novel
Chk1 inhibitor SCH900776 in combination with DNA-damaging agents and antimetabolites. Mol
Cancer Ther 11: 427-38
Morel J, Audo R, Hahne M, Combe B (2005) Tumor necrosis factor-related apoptosis-inducing ligand
(TRAIL) induces rheumatoid arthritis synovial fibroblast proliferation through mitogen-activated
protein kinases and phosphatidylinositol 3-kinase/Akt. J Biol Chem 280: 15709-18
Muhlenbeck F, Schneider P, Bodmer JL, Schwenzer R, Hauser A, Schubert G, Scheurich P, Moosmayer
D, Tschopp J, Wajant H (2000) The tumor necrosis factor-related apoptosis-inducing ligand
receptors TRAIL-R1 and TRAIL-R2 have distinct cross-linking requirements for initiation of
apoptosis and are non-redundant in JNK activation. J Biol Chem 275: 32208-13
Muhlethaler-Mottet A, Flahaut M, Bourloud KB, Auderset K, Meier R, Joseph JM, Gross N (2006)
Histone deacetylase inhibitors strongly sensitise neuroblastoma cells to TRAIL-induced apoptosis
by a caspases-dependent increase of the pro- to anti-apoptotic proteins ratio. BMC Cancer 6: 214
Nagane M, Pan G, Weddle JJ, Dixit VM, Cavenee WK, Huang HJ (2000) Increased death receptor 5
expression by chemotherapeutic agents in human gliomas causes synergistic cytotoxicity with tumor
necrosis factor-related apoptosis-inducing ligand in vitro and in vivo. Cancer Res 60: 847-53
Nahacka Z, Svadlenka J, Peterka M, Ksandrova M, Benesova S, Neuzil J, Andera L (2018) TRAIL
induces apoptosis but not necroptosis in colorectal and pancreatic cancer cells preferentially via the
TRAIL-R2/DR5 receptor. Biochim Biophys Acta 1865: 522-531
Nakata S, Yoshida T, Horinaka M, Shiraishi T, Wakada M, Sakai T (2004) Histone deacetylase
inhibitors upregulate death receptor 5/TRAIL-R2 and sensitize apoptosis induced by TRAIL/APO2L
in human malignant tumor cells. Oncogene 23: 6261-71
Nambaru PK, Hubner T, Kock K, Mews S, Grube M, Payen L, Guitton J, Sendler M, Jedlitschky G,
Rimmbach C, Rosskopf D, Kowalczyk DW, Kroemer HK, Weiss FU, Mayerle J, Lerch MM, Ritter
CA (2011) Drug efflux transporter multidrug resistance-associated protein 5 affects sensitivity of
pancreatic cancer cell lines to the nucleoside anticancer drug 5-fluorouracil. Drug Metab Dispos 39:
132-9
Naoum GE, Buchsbaum DJ, Tawadros F, Farooqi A, Arafat WO (2017) Journey of TRAIL from Bench
to Bedside and its Potential Role in Immuno-Oncology. Oncol Rev 11: 332
Naumann I, Kappler R, von Schweinitz D, Debatin KM, Fulda S (2011) Bortezomib primes
neuroblastoma cells for TRAIL-induced apoptosis by linking the death receptor to the mitochondrial
pathway. Clin Cancer Res 17: 3204-18
Nazim UM, Rasheduzzaman M, Lee YJ, Seol DW, Park SY (2017) Enhancement of TRAIL-induced
apoptosis by 5-fluorouracil requires activating Bax and p53 pathways in TRAIL-resistant lung
cancers. Oncotarget 8: 18095-18105
Ndozangue-Touriguine O, Sebbagh M, Merino D, Micheau O, Bertoglio J, Breard J (2008) A
mitochondrial block and expression of XIAP lead to resistance to TRAIL-induced apoptosis during
progression to metastasis of a colon carcinoma. Oncogene 27: 6012-22
Nesterov A, Lu X, Johnson M, Miller GJ, Ivashchenko Y, Kraft AS (2001) Elevated AKT activity
protects the prostate cancer cell line LNCaP from TRAIL-induced apoptosis. J Biol Chem 276:
10767-74
Hyršlová Vaculová 2018
45
Neuzil J, Swettenham E, Gellert N (2004) Sensitization of mesothelioma to TRAIL apoptosis by
inhibition of histone deacetylase: role of Bcl-xL down-regulation. Biochem Biophys Res Commun
314: 186-91
Newsom-Davis T, Prieske S, Walczak H (2009) Is TRAIL the holy grail of cancer therapy? Apoptosis
14: 607-23
Oguri T, Bessho Y, Achiwa H, Ozasa H, Maeno K, Maeda H, Sato S, Ueda R (2007) MRP8/ABCC11
directly confers resistance to 5-fluorouracil. Mol Cancer Ther 6: 122-7
Olsson M, Zhivotovsky B (2011) Caspases and cancer. Cell Death Differ 18: 1441-9
Ouyang W, Yang C, Liu Y, Xiong J, Zhang J, Zhong Y, Zhang G, Zhou F, Zhou Y, Xie C (2011)
Redistribution of DR4 and DR5 in lipid rafts accounts for the sensitivity to TRAIL in NSCLC cells.
Int J Oncol 39: 1577-86
Ozawa F, Friess H, Kleeff J, Xu ZW, Zimmermann A, Sheikh MS, Buchler MW (2001) Effects and
expression of TRAIL and its apoptosis-promoting receptors in human pancreatic cancer. Cancer Lett
163: 71-81
Ozoren N, El-Deiry WS (2002) Defining characteristics of Types I and II apoptotic cells in response to
TRAIL. Neoplasia 4: 551-7
Ozoren N, Fisher MJ, Kim K, Liu CX, Genin A, Shifman Y, Dicker DT, Spinner NB, Lisitsyn NA, ElDeiry
WS (2000) Homozygous deletion of the death receptor DR4 gene in a nasopharyngeal cancer
cell line is associated with TRAIL resistance. Int J Oncol 16: 917-25
Pai SI, Wu GS, Ozoren N, Wu L, Jen J, Sidransky D, El-Deiry WS (1998) Rare loss-of-function mutation
of a death receptor gene in head and neck cancer. Cancer Res 58: 3513-8
Pan G, Ni J, Wei YF, Yu G, Gentz R, Dixit VM (1997b) An antagonist decoy receptor and a death
domain-containing receptor for TRAIL. Science 277: 815-8
Pan G, Ni J, Yu G, Wei YF, Dixit VM (1998) TRUNDD, a new member of the TRAIL receptor family
that antagonizes TRAIL signalling. FEBS Lett 424: 41-5
Pan G, O'Rourke K, Chinnaiyan AM, Gentz R, Ebner R, Ni J, Dixit VM (1997a) The receptor for the
cytotoxic ligand TRAIL. Science 276: 111-3
Papenfuss K, Cordier SM, Walczak H (2008) Death receptors as targets for anti-cancer therapy. J Cell
Mol Med 12: 2566-85
Park S, Cho DH, Andera L, Suh N, Kim I (2013) Curcumin enhances TRAIL-induced apoptosis of
breast cancer cells by regulating apoptosis-related proteins. Mol Cell Biochem 383: 39-48
Pennarun B, Meijer A, de Vries EG, Kleibeuker JH, Kruyt F, de Jong S (2010) Playing the DISC: turning
on TRAIL death receptor-mediated apoptosis in cancer. Biochim Biophys Acta 1805: 123-40
Peters GJ, Backus HH, Freemantle S, van Triest B, Codacci-Pisanelli G, van der Wilt CL, Smid K,
Lunec J, Calvert AH, Marsh S, McLeod HL, Bloemena E, Meijer S, Jansen G, van Groeningen CJ,
Pinedo HM (2002) Induction of thymidylate synthase as a 5-fluorouracil resistance mechanism.
Biochim Biophys Acta 1587: 194-205
Pfeffer CM, Singh ATK (2018) Apoptosis: A Target for Anticancer Therapy. Int J Mol Sci 19, 448
Hyršlová Vaculová 2018
46
Pitti RM, Marsters SA, Ruppert S, Donahue CJ, Moore A, Ashkenazi A (1996) Induction of apoptosis
by Apo-2 ligand, a new member of the tumor necrosis factor cytokine family. J Biol Chem 271:
12687-90
Prochazka L, Turanek J, Tesarik R, Knotigova P, Polaskova P, Andrysik Z, Kozubik A, Zak F, Sova P,
Neuzil J, Machala M (2007) Apoptosis and inhibition of gap-junctional intercellular communication
induced by LA-12, a novel hydrophobic platinum(IV) complex. Arch Biochem Biophys 462: 54-61
Psahoulia FH, Drosopoulos KG, Doubravska L, Andera L, Pintzas A (2007) Quercetin enhances
TRAIL-mediated apoptosis in colon cancer cells by inducing the accumulation of death receptors in
lipid rafts. Mol Cancer Ther 6: 2591-9
Puduvalli VK, Sampath D, Bruner JM, Nangia J, Xu R, Kyritsis AP (2005) TRAIL-induced apoptosis
in gliomas is enhanced by Akt-inhibition and is independent of JNK activation. Apoptosis 10: 233-
43
Ralff M, El-Deiry W (2018) TRAIL pathway targeting therapeutics. Expert Review of Precision
Medicine and Drug Development: 1-8
Raulf N, El-Attar R, Kulms D, Lecis D, Delia D, Walczak H, Papenfuss K, Odell E, Tavassoli M (2014)
Differential response of head and neck cancer cell lines to TRAIL or Smac mimetics is associated
with the cellular levels and activity of caspase-8 and caspase-10. Br J Cancer 111: 1955-64
Ravi R, Bedi GC, Engstrom LW, Zeng Q, Mookerjee B, Gelinas C, Fuchs EJ, Bedi A (2001) Regulation
of death receptor expression and TRAIL/Apo2L-induced apoptosis by NF-kappaB. Nat Cell Biol 3:
409-16
Ravi R, Jain AJ, Schulick RD, Pham V, Prouser TS, Allen H, Mayer EG, Yu H, Pardoll DM, Ashkenazi
A, Bedi A (2004) Elimination of hepatic metastases of colon cancer cells via p53-independent crosstalk
between irinotecan and Apo2 ligand/TRAIL. Cancer Res 64: 9105-14
Reis CR, Chen PH, Bendris N, Schmid SL (2017) TRAIL-death receptor endocytosis and apoptosis are
selectively regulated by dynamin-1 activation. Proc Natl Acad Sci U S A 114: 504-509
Repnik U, Cesen MH, Turk B (2013) The endolysosomal system in cell death and survival. Cold Spring
Harb Perspect Biol 5: a008755
Ricci MS, Kim SH, Ogi K, Plastaras JP, Ling J, Wang W, Jin Z, Liu YY, Dicker DT, Chiao PJ, Flaherty
KT, Smith CD, El-Deiry WS (2007) Reduction of TRAIL-induced Mcl-1 and cIAP2 by c-Myc or
sorafenib sensitizes resistant human cancer cells to TRAIL-induced death. Cancer Cell 12: 66-80
Rosato RR, Almenara JA, Coe S, Grant S (2007) The multikinase inhibitor sorafenib potentiates TRAIL
lethality in human leukemia cells in association with Mcl-1 and cFLIPL down-regulation. Cancer
Res 67: 9490-500
Rossin A, Derouet M, Abdel-Sater F, Hueber AO (2009) Palmitoylation of the TRAIL receptor DR4
confers an efficient TRAIL-induced cell death signalling. Biochem J 419: 185-92
Roubalova E, Kvardova V, Hrstka R, Borilova S, Michalova E, Dubska L, Muller P, Sova P, Vojtesek
B (2010) The effect of cellular environment and p53 status on the mode of action of the platinum
derivative LA-12. Invest New Drugs 28: 445-53
Roue G, Perez-Galan P, Lopez-Guerra M, Villamor N, Campo E, Colomer D (2007) Selective inhibition
of IkappaB kinase sensitizes mantle cell lymphoma B cells to TRAIL by decreasing cellular FLIP
level. J Immunol 178: 1923-30
Hyršlová Vaculová 2018
47
Rufini A, Melino G (2011) Cell death pathology: the war against cancer. Biochem Biophys Res Commun
414: 445-50
Ryu HS, Chang KH, Chang SJ, Kim MS, Joo HJ, Oh KS (2000) Expression of TRAIL (TNF-related
apoptosis-inducing ligand) receptors in cervical cancer. Int J Gynecol Cancer 10: 417-424
Samadder P, Suchankova T, Hylse O, Khirsariya P, Nikulenkov F, Drapela S, Strakova N, Vanhara P,
Vasickova K, Kolarova H, Bino L, Bittova M, Ovesna P, Kollar P, Fedr R, Esner M, Jaros J, Hampl
A, Krejci L, Paruch K, Soucek K (2017) Synthesis and Profiling of a Novel Potent Selective Inhibitor
of CHK1 Kinase Possessing Unusual N-trifluoromethylpyrazole Pharmacophore Resistant to
Metabolic N-dealkylation. Mol Cancer Ther 16: 1831-1842
Sarosiek KA, Fraser C, Muthalagu N, Bhola PD, Chang W, McBrayer SK, Cantlon A, Fisch S, GolombMello
G, Ryan JA, Deng J, Jian B, Corbett C, Goldenberg M, Madsen JR, Liao R, Walsh D, Sedivy
J, Murphy DJ, Carrasco DR, Robinson S, Moslehi J, Letai A (2017) Developmental Regulation of
Mitochondrial Apoptosis by c-Myc Governs Age- and Tissue-Specific Sensitivity to Cancer
Therapeutics. Cancer Cell 31: 142-156
Sarosiek KA, Letai A (2016) Directly targeting the mitochondrial pathway of apoptosis for cancer
therapy using BH3 mimetics - recent successes, current challenges and future promise. FEBS J 283:
3523-3533
Sarosiek KA, Ni Chonghaile T, Letai A (2013) Mitochondria: gatekeepers of response to chemotherapy.
Trends Cell Biol 23: 612-9
Saulle E, Petronelli A, Pasquini L, Petrucci E, Mariani G, Biffoni M, Ferretti G, Scambia G, BenedettiPanici
P, Cognetti F, Humphreys R, Peschle C, Testa U (2007) Proteasome inhibitors sensitize
ovarian cancer cells to TRAIL induced apoptosis. Apoptosis 12: 635-55
Sayers TJ, Murphy WJ (2006) Combining proteasome inhibition with TNF-related apoptosis-inducing
ligand (Apo2L/TRAIL) for cancer therapy. Cancer Immunol Immunother 55: 76-84
Screaton GR, Mongkolsapaya J, Xu XN, Cowper AE, McMichael AJ, Bell JI (1997) TRICK2, a new
alternatively spliced receptor that transduces the cytotoxic signal from TRAIL. Curr Biol 7: 693-6
Secchiero P, Gonelli A, Carnevale E, Milani D, Pandolfi A, Zella D, Zauli G (2003) TRAIL promotes
the survival and proliferation of primary human vascular endothelial cells by activating the Akt and
ERK pathways. Circulation 107: 2250-6
Secchiero P, Zerbinati C, Rimondi E, Corallini F, Milani D, Grill V, Forti G, Capitani S, Zauli G (2004)
TRAIL promotes the survival, migration and proliferation of vascular smooth muscle cells. Cell Mol
Life Sci 61: 1965-74
Seol DW, Li J, Seol MH, Park SY, Talanian RV, Billiar TR (2001) Signaling events triggered by tumor
necrosis factor-related apoptosis-inducing ligand (TRAIL): caspase-8 is required for TRAIL-induced
apoptosis. Cancer Res 61: 1138-43
Shamimi-Noori S, Yeow WS, Ziauddin MF, Xin H, Tran TL, Xie J, Loehfelm A, Patel P, Yang J,
Schrump DS, Fang BL, Nguyen DM (2008) Cisplatin enhances the antitumor effect of tumor necrosis
factor-related apoptosis-inducing ligand gene therapy via recruitment of the mitochondria-dependent
death signaling pathway. Cancer Gene Ther 15: 356-70
Shankar S, Singh TR, Srivastava RK (2004) Ionizing radiation enhances the therapeutic potential of
TRAIL in prostate cancer in vitro and in vivo: Intracellular mechanisms. Prostate 61: 35-49
Hyršlová Vaculová 2018
48
Sheikh MS, Burns TF, Huang Y, Wu GS, Amundson S, Brooks KS, Fornace AJ, Jr., el-Deiry WS (1998)
p53-dependent and -independent regulation of the death receptor KILLER/DR5 gene expression in
response to genotoxic stress and tumor necrosis factor alpha. Cancer Res 58: 1593-8
Sheridan JP, Marsters SA, Pitti RM, Gurney A, Skubatch M, Baldwin D, Ramakrishnan L, Gray CL,
Baker K, Wood WI, Goddard AD, Godowski P, Ashkenazi A (1997) Control of TRAIL-induced
apoptosis by a family of signaling and decoy receptors. Science 277: 818-21
Shetty S, Graham BA, Brown JG, Hu X, Vegh-Yarema N, Harding G, Paul JT, Gibson SB (2005)
Transcription factor NF-kappaB differentially regulates death receptor 5 expression involving
histone deacetylase 1. Mol Cell Biol 25: 5404-16
Shi X, Liu S, Kleeff J, Friess H, Buchler MW (2002) Acquired resistance of pancreatic cancer cells
towards 5-Fluorouracil and gemcitabine is associated with altered expression of apoptosis-regulating
genes. Oncology 62: 354-62
Shirley S, Micheau O (2013) Targeting c-FLIP in cancer. Cancer Lett 332: 141-50
Shirley S, Morizot A, Micheau O (2011) Regulating TRAIL receptor-induced cell death at the
membrane : a deadly discussion. Recent Pat Anticancer Drug Discov 6: 311-23
Shivapurkar N, Reddy J, Matta H, Sathyanarayana UG, Huang CX, Toyooka S, Minna JD, Chaudhary
PM, Gazdar AF (2002a) Loss of expression of death-inducing signaling complex (DISC) components
in lung cancer cell lines and the influence of MYC amplification. Oncogene 21: 8510-4
Shivapurkar N, Toyooka S, Eby MT, Huang CX, Sathyanarayana UG, Cunningham HT, Reddy JL,
Brambilla E, Takahashi T, Minna JD, Chaudhary PM, Gazdar AF (2002b) Differential inactivation
of caspase-8 in lung cancers. Cancer Biol Ther 1: 65-9
Shlyakhtina Y, Pavet V, Gronemeyer H (2017) Dual role of DR5 in death and survival signaling leads
to TRAIL resistance in cancer cells. Cell Death Dis 8: e3025
Schneider-Brachert W, Heigl U, Ehrenschwender M (2013) Membrane trafficking of death receptors:
implications on signalling. Int J Mol Sci 14: 14475-503
Schulze-Bergkamen H, Ehrenberg R, Hickmann L, Vick B, Urbanik T, Schimanski CC, Berger MR,
Schad A, Weber A, Heeger S, Galle PR, Moehler M (2008) Bcl-x(L) and Myeloid cell leukaemia-1
contribute to apoptosis resistance of colorectal cancer cells. World J Gastroenterol 14: 3829-40
Schulze-Bergkamen H, Fleischer B, Schuchmann M, Weber A, Weinmann A, Krammer PH, Galle PR
(2006) Suppression of Mcl-1 via RNA interference sensitizes human hepatocellular carcinoma cells
towards apoptosis induction. BMC Cancer 6: 232
Simonet WS, Lacey DL, Dunstan CR, Kelley M, Chang MS, Luthy R, Nguyen HQ, Wooden S, Bennett
L, Boone T, Shimamoto G, DeRose M, Elliott R, Colombero A, Tan HL, Trail G, Sullivan J, Davy
E, Bucay N, Renshaw-Gegg L, Hughes TM, Hill D, Pattison W, Campbell P, Sander S, Van G,
Tarpley J, Derby P, Lee R, Boyle WJ (1997) Osteoprotegerin: a novel secreted protein involved in
the regulation of bone density. Cell 89: 309-19
Singh TR, Shankar S, Chen X, Asim M, Srivastava RK (2003) Synergistic interactions of
chemotherapeutic drugs and tumor necrosis factor-related apoptosis-inducing ligand/Apo-2 ligand
on apoptosis and on regression of breast carcinoma in vivo. Cancer Res 63: 5390-400
Hyršlová Vaculová 2018
49
Singh TR, Shankar S, Srivastava RK (2005) HDAC inhibitors enhance the apoptosis-inducing potential
of TRAIL in breast carcinoma. Oncogene 24: 4609-23
Sinicrope FA, Penington RC, Tang XM (2004) Tumor necrosis factor-related apoptosis-inducing ligandinduced
apoptosis is inhibited by Bcl-2 but restored by the small molecule Bcl-2 inhibitor, HA 14-1,
in human colon cancer cells. Clin Cancer Res 10: 8284-92
Skender B, Hofmanova J, Slavik J, Jelinkova I, Machala M, Moyer MP, Kozubik A, Hyrslova
Vaculova A (2014) DHA-mediated enhancement of TRAIL-induced apoptosis in colon cancer
cells is associated with engagement of mitochondria and specific alterations in sphingolipid
metabolism. Biochim Biophys Acta 1841: 1308-17
Skender B, Vaculova AH, Hofmanova J (2012) Docosahexaenoic fatty acid (DHA) in the
regulation of colon cell growth and cell death: a review. Biomed Pap Med Fac Univ Palacky
Olomouc Czech Repub 156: 186-99
Soncini M, Santoro F, Gutierrez A, Frige G, Romanenghi M, Botrugno OA, Pallavicini I, Pelicci P, Di
Croce L, Minucci S (2013) The DNA demethylating agent decitabine activates the TRAIL pathway
and induces apoptosis in acute myeloid leukemia. Biochim Biophys Acta 1832: 114-20
Song JH, Kandasamy K, Kraft AS (2008) ABT-737 induces expression of the death receptor 5 and
sensitizes human cancer cells to TRAIL-induced apoptosis. J Biol Chem 283: 25003-13
Sosna J, Philipp S, Fuchslocher Chico J, Saggau C, Fritsch J, Foll A, Plenge J, Arenz C, Pinkert T,
Kalthoff H, Trauzold A, Schmitz I, Schutze S, Adam D (2016) Differences and Similarities in
TRAIL- and Tumor Necrosis Factor-Mediated Necroptotic Signaling in Cancer Cells. Mol Cell Biol
36: 2626-44
Soung YH, Lee JW, Kim SY, Jang J, Park YG, Park WS, Nam SW, Lee JY, Yoo NJ, Lee SH (2005)
CASPASE-8 gene is inactivated by somatic mutations in gastric carcinomas. Cancer Res 65: 815-21
Sova P, Mistr A, Kroutil A, Zak F, Pouckova P, Zadinova M (2005) Preclinical anti-tumor activity of a
new oral platinum(IV) drug LA-12. Anticancer Drugs 16: 653-7
Sova P, Mistr A, Kroutil A, Zak F, Pouckova P, Zadinova M (2006) Comparative anti-tumor efficacy
of two orally administered platinum(IV) drugs in nude mice bearing human tumor xenografts.
Anticancer Drugs 17: 201-6
Sprick MR, Rieser E, Stahl H, Grosse-Wilde A, Weigand MA, Walczak H (2002) Caspase-10 is
recruited to and activated at the native TRAIL and CD95 death-inducing signalling complexes in a
FADD-dependent manner but can not functionally substitute caspase-8. EMBO J 21: 4520-30
Stagni V, Mingardi M, Santini S, Giaccari D, Barila D (2010) ATM kinase activity modulates cFLIP
protein levels: potential interplay between DNA damage signalling and TRAIL-induced apoptosis.
Carcinogenesis 31: 1956-63
Stuckey DW, Shah K (2013) TRAIL on trial: preclinical advances in cancer therapy. Trends Mol Med
19: 685-94
Su Z, Yang Z, Xie L, DeWitt JP, Chen Y (2016) Cancer therapy in the necroptosis era. Cell Death Differ
23: 748-56
Svihalkova-Sindlerova L, Foltinova V, Vaculova A, Horvath V, Soucek K, Sova P, Hofmanova J,
Kozubik A (2010) LA-12 overcomes confluence-dependent resistance of HT-29 colon cancer
cells to Pt (II) compounds. Anticancer Res 30: 1183-8
Hyršlová Vaculová 2018
50
Takimoto R, El-Deiry WS (2000) Wild-type p53 transactivates the KILLER/DR5 gene through an
intronic sequence-specific DNA-binding site. Oncogene 19: 1735-43
Taniai M, Grambihler A, Higuchi H, Werneburg N, Bronk SF, Farrugia DJ, Kaufmann SH, Gores GJ
(2004) Mcl-1 mediates tumor necrosis factor-related apoptosis-inducing ligand resistance in human
cholangiocarcinoma cells. Cancer Res 64: 3517-24
Taylor RC, Cullen SP, Martin SJ (2008) Apoptosis: controlled demolition at the cellular level. Nat Rev
Mol Cell Biol 9: 231-41
Timmer JC, Salvesen GS (2007) Caspase substrates. Cell Death Differ 14: 66-72
Timucin AC, Basaga H, Kutuk O (2018) Selective targeting of antiapoptotic BCL-2 proteins in cancer.
Med Res Rev, 21516
Tomasetti M, Andera L, Alleva R, Borghi B, Neuzil J, Procopio A (2006) Alpha-tocopheryl succinate
induces DR4 and DR5 expression by a p53-dependent route: implication for sensitisation of resistant
cancer cells to TRAIL apoptosis. FEBS Lett 580: 1925-31
Tomasetti M, Rippo MR, Alleva R, Moretti S, Andera L, Neuzil J, Procopio A (2004) Alpha-tocopheryl
succinate and TRAIL selectively synergise in induction of apoptosis in human malignant
mesothelioma cells. Br J Cancer 90: 1644-53
Tran SE, Holmstrom TH, Ahonen M, Kahari VM, Eriksson JE (2001) MAPK/ERK overrides the
apoptotic signaling from Fas, TNF, and TRAIL receptors. J Biol Chem 276: 16484-90
Trauzold A, Siegmund D, Schniewind B, Sipos B, Egberts J, Zorenkov D, Emme D, Roder C, Kalthoff
H, Wajant H (2006) TRAIL promotes metastasis of human pancreatic ductal adenocarcinoma.
Oncogene 25: 7434-9
Trivedi R, Mishra DP (2015) Trailing TRAIL Resistance: Novel Targets for TRAIL Sensitization in
Cancer Cells. Front Oncol 5: 69
Truneh A, Sharma S, Silverman C, Khandekar S, Reddy MP, Deen KC, McLaughlin MM, Srinivasula
SM, Livi GP, Marshall LA, Alnemri ES, Williams WV, Doyle ML (2000) Temperature-sensitive
differential affinity of TRAIL for its receptors. DR5 is the highest affinity receptor. J Biol Chem 275:
23319-25
Tsai WS, Yeow WS, Chua A, Reddy RM, Nguyen DM, Schrump DS (2006) Enhancement of
Apo2L/TRAIL-mediated cytotoxicity in esophageal cancer cells by cisplatin. Mol Cancer Ther 5:
2977-90
Tummers B, Green DR (2017) Caspase-8: regulating life and death. Immunol Rev 277: 76-89
Twomey JD, Kim SR, Zhao L, Bozza WP, Zhang B (2015) Spatial dynamics of TRAIL death receptors
in cancer cells. Drug Resist Updat 19: 13-21
Vaculova A, Hofmanova J, Andera L, Kozubik A (2005) TRAIL and docosahexaenoic acid
cooperate to induce HT-29 colon cancer cell death. Cancer Lett 229: 43-8
Vaculova A, Hofmanova J, Soucek K, Kozubik A (2006) Different modulation of TRAIL-induced
apoptosis by inhibition of pro-survival pathways in TRAIL-sensitive and TRAIL-resistant
colon cancer cells. FEBS Lett 580: 6565-9
Hyršlová Vaculová 2018
51
Vaculova A, Hofmanova J, Zatloukalova J, Kozubik A (2009) Differences in TRAIL-induced
changes of Mcl-1 expression among distinct human colon epithelial cell lines. Exp Cell Res 315:
3259-66
Vaculova A, Kaminskyy V, Jalalvand E, Surova O, Zhivotovsky B (2010) Doxorubicin and
etoposide sensitize small cell lung carcinoma cells expressing caspase-8 to TRAIL. Mol Cancer
9: 87
Vaculova A, Zhivotovsky B (2008) Caspases: determination of their activities in apoptotic cells.
Methods Enzymol 442: 157-81
van Geelen CM, Westra JL, de Vries EG, Boersma-van Ek W, Zwart N, Hollema H, Boezen HM,
Mulder NH, Plukker JT, de Jong S, Kleibeuker JH, Koornstra JJ (2006) Prognostic significance of
tumor necrosis factor-related apoptosis-inducing ligand and its receptors in adjuvantly treated stage
III colon cancer patients. J Clin Oncol 24: 4998-5004
van Triest B, Pinedo HM, van Hensbergen Y, Smid K, Telleman F, Schoenmakers PS, van der Wilt CL,
van Laar JA, Noordhuis P, Jansen G, Peters GJ (1999) Thymidylate synthase level as the main
predictive parameter for sensitivity to 5-fluorouracil, but not for folate-based thymidylate synthase
inhibitors, in 13 nonselected colon cancer cell lines. Clin Cancer Res 5: 643-54
Van Valen F, Fulda S, Schafer KL, Truckenbrod B, Hotfilder M, Poremba C, Debatin KM, Winkelmann
W (2003) Selective and nonselective toxicity of TRAIL/Apo2L combined with chemotherapy in
human bone tumour cells vs. normal human cells. Int J Cancer 107: 929-40
Varfolomeev E, Maecker H, Sharp D, Lawrence D, Renz M, Vucic D, Ashkenazi A (2005) Molecular
determinants of kinase pathway activation by Apo2 ligand/tumor necrosis factor-related apoptosisinducing
ligand. J Biol Chem 280: 40599-608
Verhagen AM, Ekert PG, Pakusch M, Silke J, Connolly LM, Reid GE, Moritz RL, Simpson RJ, Vaux
DL (2000) Identification of DIABLO, a mammalian protein that promotes apoptosis by binding to
and antagonizing IAP proteins. Cell 102: 43-53
Vilimanovich U, Bumbasirevic V (2008) TRAIL induces proliferation of human glioma cells by cFLIPL-mediated
activation of ERK1/2. Cell Mol Life Sci 65: 814-26
Violette S, Poulain L, Dussaulx E, Pepin D, Faussat AM, Chambaz J, Lacorte JM, Staedel C, Lesuffleur
T (2002) Resistance of colon cancer cells to long-term 5-fluorouracil exposure is correlated to the
relative level of Bcl-2 and Bcl-X(L) in addition to Bax and p53 status. Int J Cancer 98: 498-504
Voelkel-Johnson C, Hannun YA, El-Zawahry A (2005) Resistance to TRAIL is associated with defects
in ceramide signaling that can be overcome by exogenous C6-ceramide without requiring downregulation
of cellular FLICE inhibitory protein. Mol Cancer Ther 4: 1320-7
Vogler M, Durr K, Jovanovic M, Debatin KM, Fulda S (2007) Regulation of TRAIL-induced apoptosis
by XIAP in pancreatic carcinoma cells. Oncogene 26: 248-57
Voigt S, Philipp S, Davarnia P, Winoto-Morbach S, Roder C, Arenz C, Trauzold A, Kabelitz D, Schutze
S, Kalthoff H, Adam D (2014) TRAIL-induced programmed necrosis as a novel approach to
eliminate tumor cells. BMC Cancer 14: 74
von Karstedt S, Conti A, Nobis M, Montinaro A, Hartwig T, Lemke J, Legler K, Annewanter F,
Campbell AD, Taraborrelli L, Grosse-Wilde A, Coy JF, El-Bahrawy MA, Bergmann F, Koschny R,
Werner J, Ganten TM, Schweiger T, Hoetzenecker K, Kenessey I, Hegedus B, Bergmann M, Hauser
C, Egberts JH, Becker T, Rocken C, Kalthoff H, Trauzold A, Anderson KI, Sansom OJ, Walczak H
Hyršlová Vaculová 2018
52
(2015) Cancer cell-autonomous TRAIL-R signaling promotes KRAS-driven cancer progression,
invasion, and metastasis. Cancer Cell 27: 561-73
von Karstedt S, Montinaro A, Walczak H (2017) Exploring the TRAILs less travelled: TRAIL in cancer
biology and therapy. Nat Rev Cancer 17: 352-366
Vondalova Blanarova O, Jelinkova I, Hyrslova Vaculova A, Sova P, Hofmanova J, Kozubik A
(2013) Higher anti-tumour efficacy of platinum(IV) complex LA-12 is associated with its ability
to bypass M-phase entry block induced in oxaliplatin-treated human colon cancer cells. Cell
Prolif 46: 665-76
Vondalova Blanarova O, Jelinkova I, Szoor A, Skender B, Soucek K, Horvath V, Vaculova A,
Andera L, Sova P, Szollosi J, Hofmanova J, Vereb G, Kozubik A (2011) Cisplatin and a potent
platinum(IV) complex-mediated enhancement of TRAIL-induced cancer cells killing is
associated with modulation of upstream events in the extrinsic apoptotic pathway.
Carcinogenesis 32: 42-51
Vondalova Blanarova O, Safarikova B, Herudkova J, Krkoska M, Tomankova S, Kahounova Z,
Andera L, Bouchal J, Kharaishvili G, Kral M, Sova P, Kozubik A, Hyrslova Vaculova A (2017)
Cisplatin or LA-12 enhance killing effects of TRAIL in prostate cancer cells through Biddependent
stimulation of mitochondrial apoptotic pathway but not caspase-10. PLoS One 12:
e0188584
Wagner KW, Punnoose EA, Januario T, Lawrence DA, Pitti RM, Lancaster K, Lee D, von Goetz M,
Yee SF, Totpal K, Huw L, Katta V, Cavet G, Hymowitz SG, Amler L, Ashkenazi A (2007) Deathreceptor
O-glycosylation controls tumor-cell sensitivity to the proapoptotic ligand Apo2L/TRAIL.
Nat Med 13: 1070-7
Walczak H, Degli-Esposti MA, Johnson RS, Smolak PJ, Waugh JY, Boiani N, Timour MS, Gerhart MJ,
Schooley KA, Smith CA, Goodwin RG, Rauch CT (1997) TRAIL-R2: a novel apoptosis-mediating
receptor for TRAIL. EMBO J 16: 5386-97
Walczak H, Miller RE, Ariail K, Gliniak B, Griffith TS, Kubin M, Chin W, Jones J, Woodward A, Le
T, Smith C, Smolak P, Goodwin RG, Rauch CT, Schuh JC, Lynch DH (1999) Tumoricidal activity
of tumor necrosis factor-related apoptosis-inducing ligand in vivo. Nat Med 5: 157-63
Wang G, Zhan Y, Wang H, Li W (2012) ABT-263 sensitizes TRAIL-resistant hepatocarcinoma cells
by downregulating the Bcl-2 family of anti-apoptotic protein. Cancer Chemother Pharmacol 69:
799-805
Wang H, Yang T, Wu X (2015) 5-Fluorouracil preferentially sensitizes mutant KRAS non-small cell
lung carcinoma cells to TRAIL-induced apoptosis. Mol Oncol 9: 1815-24
Wang S, El-Deiry WS (2004) Inducible silencing of KILLER/DR5 in vivo promotes bioluminescent
colon tumor xenograft growth and confers resistance to chemotherapeutic agent 5-fluorouracil.
Cancer Res 64: 6666-72
Wang S, Ren W, Liu J, Lahat G, Torres K, Lopez G, Lazar AJ, Hayes-Jordan A, Liu K, Bankson J,
Hazle JD, Lev D (2010) TRAIL and doxorubicin combination induces proapoptotic and
antiangiogenic effects in soft tissue sarcoma in vivo. Clin Cancer Res 16: 2591-604
Weber T, Lu M, Andera L, Lahm H, Gellert N, Fariss MW, Korinek V, Sattler W, Ucker DS, Terman
A, Schroder A, Erl W, Brunk UT, Coffey RJ, Weber C, Neuzil J (2002) Vitamin E succinate is a
potent novel antineoplastic agent with high selectivity and cooperativity with tumor necrosis factorrelated
apoptosis-inducing ligand (Apo2 ligand) in vivo. Clin Cancer Res 8: 863-9
Hyršlová Vaculová 2018
53
Wei MC, Zong WX, Cheng EH, Lindsten T, Panoutsakopoulou V, Ross AJ, Roth KA, MacGregor GR,
Thompson CB, Korsmeyer SJ (2001) Proapoptotic BAX and BAK: a requisite gateway to
mitochondrial dysfunction and death. Science 292: 727-30
White-Gilbertson S, Mullen T, Senkal C, Lu P, Ogretmen B, Obeid L, Voelkel-Johnson C (2009)
Ceramide synthase 6 modulates TRAIL sensitivity and nuclear translocation of active caspase-3 in
colon cancer cells. Oncogene 28: 1132-41
Wiley SR, Schooley K, Smolak PJ, Din WS, Huang CP, Nicholl JK, Sutherland GR, Smith TD, Rauch
C, Smith CA, et al. (1995) Identification and characterization of a new member of the TNF family
that induces apoptosis. Immunity 3: 673-82
Wu XX, Kakehi Y (2009) Enhancement of lexatumumab-induced apoptosis in human solid cancer cells
by Cisplatin in caspase-dependent manner. Clin Cancer Res 15: 2039-47
Xiao CW, Yan X, Li Y, Reddy SA, Tsang BK (2003) Resistance of human ovarian cancer cells to tumor
necrosis factor alpha is a consequence of nuclear factor kappaB-mediated induction of Fas-associated
death domain-like interleukin-1beta-converting enzyme-like inhibitory protein. Endocrinology 144:
623-30
Xu J, Xu Z, Zhou JY, Zhuang Z, Wang E, Boerner J, Wu GS (2013) Regulation of the Src-PP2A
interaction in tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-induced
apoptosis. J Biol Chem 288: 33263-71
Xu J, Zhou JY, Wei WZ, Wu GS (2010) Activation of the Akt survival pathway contributes to TRAIL
resistance in cancer cells. PLoS One 5: e10226
Xu J, Zhou JY, Xu Z, Kho DH, Zhuang Z, Raz A, Wu GS (2014) The role of Cullin3-mediated
ubiquitination of the catalytic subunit of PP2A in TRAIL signaling. Cell Cycle 13: 3750-8
Xu L, Qu X, Zhang Y, Hu X, Yang X, Hou K, Teng Y, Zhang J, Sada K, Liu Y (2009) Oxaliplatin
enhances TRAIL-induced apoptosis in gastric cancer cells by CBL-regulated death receptor
redistribution in lipid rafts. FEBS Lett 583: 943-8
Xu L, Zhang Y, Qu X, Che X, Guo T, Li C, Ma R, Fan Y, Ma Y, Hou K, Li D, Hu X, Liu B, Yu R, Yan
H, Gong J, Liu Y (2017) DR5-Cbl-b/c-Cbl-TRAF2 complex inhibits TRAIL-induced apoptosis by
promoting TRAF2-mediated polyubiquitination of caspase-8 in gastric cancer cells. Mol Oncol 11:
1733-1751
Xu LH, Deng CS, Zhu YQ, Liu SQ, Liu DZ (2003b) Synergistic antitumor effect of TRAIL and
doxorubicin on colon cancer cell line SW480. World J Gastroenterol 9: 1241-5
Xu ZW, Kleeff J, Friess H, Buchler MW, Solioz M (2003a) Synergistic cytotoxic effect of TRAIL and
gemcitabine in pancreatic cancer cells. Anticancer Res 23: 251-8
Yamanaka T, Shiraki K, Sugimoto K, Ito T, Fujikawa K, Ito M, Takase K, Moriyama M, Nakano T,
Suzuki A (2000) Chemotherapeutic agents augment TRAIL-induced apoptosis in human
hepatocellular carcinoma cell lines. Hepatology 32: 482-90
Yang L, Wang Y, Zheng H, Zhang D, Wu X, Sun G, Yang T (2017) Low-dose 5-fluorouracil sensitizes
HepG2 cells to TRAIL through TRAIL receptor DR5 and survivin-dependent mechanisms. J
Chemother 29: 179-188
Hyršlová Vaculová 2018
54
Yoo J, Park SS, Lee YJ (2008) Pretreatment of docetaxel enhances TRAIL-mediated apoptosis in
prostate cancer cells. J Cell Biochem 104: 1636-46
Yuan X, Gajan A, Chu Q, Xiong H, Wu K, Wu GS (2018) Developing TRAIL/TRAIL death receptorbased
cancer therapies. Cancer Metastasis Rev, 1-16
Zak F, Turanek J, Kroutil A, Sova P, Mistr A, Poulova A, Mikolin P, Zak Z, Kasna A, Zaluska D, Neca
J, Sindlerova L, Kozubik A (2004) Platinum(IV) complex with adamantylamine as nonleaving amine
group: synthesis, characterization, and in vitro antitumor activity against a panel of cisplatin-resistant
cancer cell lines. J Med Chem 47: 761-3
Zauli G, Sancilio S, Cataldi A, Sabatini N, Bosco D, Di Pietro R (2005) PI-3K/Akt and NFkappaB/IkappaBalpha
pathways are activated in Jurkat T cells in response to TRAIL treatment. J
Cell Physiol 202: 900-11
Zhang L, Zhu H, Teraishi F, Davis JJ, Guo W, Fan Z, Fang B (2005) Accelerated degradation of caspase-
8 protein correlates with TRAIL resistance in a DLD1 human colon cancer cell line. Neoplasia 7:
594-602
Zhang X, Jin TG, Yang H, DeWolf WC, Khosravi-Far R, Olumi AF (2004) Persistent c-FLIP(L)
expression is necessary and sufficient to maintain resistance to tumor necrosis factor-related
apoptosis-inducing ligand-mediated apoptosis in prostate cancer. Cancer Res 64: 7086-91
Zhang XD, Borrow JM, Zhang XY, Nguyen T, Hersey P (2003) Activation of ERK1/2 protects
melanoma cells from TRAIL-induced apoptosis by inhibiting Smac/DIABLO release from
mitochondria. Oncogene 22: 2869-81
Zhang XD, Zhang XY, Gray CP, Nguyen T, Hersey P (2001) Tumor necrosis factor-related apoptosisinducing
ligand-induced apoptosis of human melanoma is regulated by smac/DIABLO release from
mitochondria. Cancer Res 61: 7339-48
Zhang Y, Zhang B (2008) TRAIL resistance of breast cancer cells is associated with constitutive
endocytosis of death receptors 4 and 5. Mol Cancer Res 6: 1861-71
Zhao B, Li L, Cui K, Wang CL, Wang AL, Sun ZQ, Zhang B, Zhou WY, Niu ZX, Tian H, Xue Y, Li S
(2011) Mechanisms of TRAIL and gemcitabine induction of pancreatic cancer cell apoptosis. Asian
Pac J Cancer Prev 12: 2675-8
Zhivotovsky B, Orrenius S (2006) Carcinogenesis and apoptosis: paradigms and paradoxes.
Carcinogenesis 27: 1939-45
Zhu H, Huang M, Ren D, He J, Zhao F, Yi C, Huang Y (2013) The synergistic effects of low dose
fluorouracil and TRAIL on TRAIL-resistant human gastric adenocarcinoma AGS cells. Biomed Res
Int 2013: 293874
Zobalova R, McDermott L, Stantic M, Prokopova K, Dong LF, Neuzil J (2008) CD133-positive cells
are resistant to TRAIL due to up-regulation of FLIP. Biochem Biophys Res Commun 373: 567-71
Zou H, Henzel WJ, Liu X, Lutschg A, Wang X (1997) Apaf-1, a human protein homologous to C.
elegans CED-4, participates in cytochrome c-dependent activation of caspase-3. Cell 90: 405-13
(Alena Hyrslova Vaculova is an author or co-author of the citations marked in bold.)
Hyršlová Vaculová 2018
55
5. Supplement list
The Supplement part contains a selection of 18 original research articles and 1 review (out of
39 author´s publications, according to PubMed, October 2018), which are directly related to the
topic of the theses. These publications provide a detailed overview of the author´s contribution
to the research focused on the regulation of the cancer cell death, especially molecular
mechanisms of apoptosis and the novel possibilities of its modulation by selected
therapeutically interesting agents. Alena Hyrslova Vaculova is the first or corresponding author
of 11 out of the 19 publications, and substantially contributed also to the others as a co-author.
1. Vaculova A, Zhivotovsky B (2008) Caspases: determination of their activities in apoptotic
cells. Methods Enzymol 442: 157-81. IF(2008) = 2.312.
2. Svihalkova-Sindlerova L, Foltinova V, Vaculova A, Horvath V, Soucek K, Sova P,
Hofmanova J, Kozubik A (2010) LA-12 overcomes confluence-dependent resistance of HT-
29 colon cancer cells to Pt (II) compounds. Anticancer Res 30: 1183-8. IF(2010) = 1.656.
3. Vondalova Blanarova O, Jelinkova I, Hyrslova Vaculova A*, Sova P, Hofmanova J,
Kozubik A (2013) Higher anti-tumour efficacy of platinum(IV) complex LA-12 is associated
with its ability to bypass M-phase entry block induced in oxaliplatin-treated human colon
cancer cells. Cell Prolif 46: 665-76 (* corresponding author). IF(2013) = 3.280.
4. Herudkova J, Paruch K, Khirsariya P, Soucek K, Krkoska M, Vondalova Blanarova O, Sova
P, Kozubik A, Hyrslova Vaculova A* (2017) Chk1 inhibitor SCH900776 effectively
potentiates the cytotoxic effects of platinum-based chemotherapeutic drugs in human colon
cancer cells. Neoplasia 19: 830-841 (* corresponding author). IF(2017) = 4.994.
5. Laukova J, Kozubik A, Hofmanova J, Nekvindova J, Sova P, Moyer MP, Ehrmann J,
Hyrslova Vaculova A* (2015) Loss of PTEN facilitates rosiglitazone-mediated
enhancement of platinum(IV) complex LA-12-induced apoptosis in colon cancer cells. PLoS
One 10: e0141020 (* corresponding author). IF(2015) = 3.057.
6. Vondalova Blanarova O, Jelinkova I, Szoor A, Skender B, Soucek K, Horvath V, Vaculova
A, Andera L, Sova P, Szollosi J, Hofmanova J, Vereb G, Kozubik A (2011) Cisplatin and a
potent platinum(IV) complex-mediated enhancement of TRAIL-induced cancer cells killing
is associated with modulation of upstream events in the extrinsic apoptotic pathway.
Carcinogenesis 32: 42-51. IF(2011) = 5.702.
7. Jelinkova I, Safarikova B, Vondalova Blanarova O, Skender B, Hofmanova J, Sova P, Moyer
MP, Kozubik A, Kolar Z, Ehrmann J, Hyrslova Vaculova A* (2014) Platinum(IV) complex
LA-12 exerts higher ability than cisplatin to enhance TRAIL-induced cancer cell apoptosis
via stimulation of mitochondrial pathway. Biochem Pharmacol 92: 415-24 (* corresponding
author). IF(2014) = 5.009.
8. Vondalova Blanarova O, Safarikova B, Herudkova J, Krkoska M, Tomankova S, Kahounova
Z, Andera L, Bouchal J, Kharaishvili G, Kral M, Sova P, Kozubik A, Hyrslova Vaculova
A* (2017) Cisplatin or LA-12 enhance killing effects of TRAIL in prostate cancer cells
through Bid-dependent stimulation of mitochondrial apoptotic pathway but not caspase-10.
PLoS One 12: e0188584 (* corresponding author). IF(2017) = 2.776.
Hyršlová Vaculová 2018
56
9. Akpinar B, Bracht EV, Reijnders D, Safarikova B, Jelinkova I, Grandien A, Hyrslova
Vaculova A, Zhivotovsky B, Olsson M (2015) 5-Fluorouracil-induced RNA stress engages
a TRAIL-DISC-dependent apoptosis axis facilitated by p53. Oncotarget 6: 43679-97. IF(2015)
= 5.008.
10. Akpinar B, Safarikova B, Laukova J, Debnath S, Hyrslova Vaculova A, Zhivotovsky B,
Olsson M (2016) Aberrant DR5 transport through disruption of lysosomal function suggests
a novel mechanism for receptor activation. Oncotarget 7: 58286-58301. IF(2016) = 5.168.
11. Vaculova A, Kaminskyy V, Jalalvand E, Surova O, Zhivotovsky B (2010) Doxorubicin and
etoposide sensitize small cell lung carcinoma cells expressing caspase-8 to TRAIL. Mol
Cancer 9: 87-99. IF(2010) = 3.779.
12. Kaminskyy VO, Surova OV, Vaculova A, Zhivotovsky B (2011) Combined inhibition of
DNA methyltransferase and histone deacetylase restores caspase-8 expression and sensitizes
SCLC cells to TRAIL. Carcinogenesis 32: 1450-8. IF(2011) = 5.702.
13. Vaculova A, Hofmanova J, Andera L, Kozubik A (2005) TRAIL and docosahexaenoic acid
cooperate to induce HT-29 colon cancer cell death. Cancer Lett 229: 43-8. IF(2005) = 3.049.
14. Skender B, Hofmanova J, Slavik J, Jelinkova I, Machala M, Moyer MP, Kozubik A,
Hyrslova Vaculova A* (2014) DHA-mediated enhancement of TRAIL-induced apoptosis
in colon cancer cells is associated with engagement of mitochondria and specific alterations
in sphingolipid metabolism. Biochim Biophys Acta 1841: 1308-17 (* corresponding author).
IF(2014) = 5.162.
15. Vaculova A, Hofmanova J, Soucek K, Kozubik A (2006) Different modulation of TRAILinduced
apoptosis by inhibition of pro-survival pathways in TRAIL-sensitive and TRAILresistant
colon cancer cells. FEBS Lett 580: 6565-9. IF(2006) = 3.372.
16. Hofmanova J, Vaculova A, Hyzd'alova M, Kozubik A (2008) Response of normal and
colon cancer epithelial cells to TNF-family apoptotic inducers. Oncol Rep 19: 567-73.
IF(2008) = 1.524.
17. Vaculova A, Hofmanova J, Zatloukalova J, Kozubik A (2009) Differences in TRAILinduced
changes of Mcl-1 expression among distinct human colon epithelial cell lines. Exp
Cell Res 315: 3259-66. IF(2009) = 3.589.
18. Koci L, Hyzd'alova M, Vaculova A, Hofmanova J, Kozubik A (2011) Detachmentmediated
resistance to TRAIL-induced apoptosis is associated with stimulation of the
PI3K/Akt pathway in fetal and adenocarcinoma epithelial colon cells. Cytokine 55: 34-9.
IF(2011) = 3.019.
19. Horova V, Hradilova N, Jelinkova I, Koc M, Svadlenka J, Brazina J, Klima M, Slavik J,
Hyrslova Vaculova A, Andera L (2013) Inhibition of vacuolar ATPase attenuates the
TRAIL-induced activation of caspase-8 and modulates the trafficking of TRAIL
receptosomes. FEBS J 280: 3436-50. IF(2013) = 3.986.
6. Supplements 1 - 19