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Hindawi Publishing CorporationOxidative Medicine and Cellular LongevityVolume 2013 Article ID 504230 17 pageshttpdxdoiorg1011552013504230

Review ArticleThe Proapoptotic Effect of Traditional and Novel NonsteroidalAnti-Inflammatory Drugs in Mammalian and Yeast Cells

Gianluca Farrugia and Rena Balzan

Department of Physiology and Biochemistry Faculty of Medicine and Surgery University of Malta Msida MSD 2080 Malta

Correspondence should be addressed to Gianluca Farrugia gianlucafarrugiagmailcom

Received 14 May 2013 Accepted 8 July 2013

Academic Editor Paula Ludovico

Copyright copy 2013 G Farrugia and R Balzan This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Nonsteroidal anti-inflammatory drugs (NSAIDs) have long been used to treat pain fever and inflammation However mountingevidence shows thatNSAIDs such as aspirin have very promising antineoplastic propertiesThe chemopreventive antiproliferativebehaviour of NSAIDs has been associated with both their inactivation of cyclooxygenases (COX) and their ability to induceapoptosis via pathways that are largely COX-independent In this review the various proapoptotic pathways induced bytraditional and novel NSAIDs such as phospho-NSAIDs hydrogen sulfide-releasing NSAIDs and nitric oxide-releasing NSAIDsin mammalian cell lines are discussed as well as the proapoptotic effects of NSAIDs on budding yeast which retains the hallmarksof mammalian apoptosis The significance of these mechanisms in terms of the role of NSAIDs in effective cancer prevention isconsidered

1 Introduction

In recent years there has been a growing interest in aspirinand other nonsteroidal anti-inflammatory drugs (NSAIDs)because of their promising antineoplastic properties Epi-demiological clinical and experimental evidence stronglyindicates that NSAIDs exert a significant chemopreventiveantiproliferative effect on several types of cancer cells (seeTable 1) Much of the research concerning the antineoplasticeffects of NSAIDs has focused on the effect of aspirin in largebowel cancers with comparatively fewer studies carried outon the chemopreventive effects of other NSAIDs [1] In factaspirin stands as the most widely studied pharmacologicalagent for the chemoprevention of colorectal malignancieswith numerous clinical trials being carried out to examine itsrole in the prevention of adenomas colorectal carcinomasand inherited colorectal neoplasias such as the Lynch syn-drome and familial adenomatous polyposis (FAP) [2] Suchfocus on aspirin may be due in large part to the increasinglyhigh prevalence and social impact of human colorectal cancerin recent years [2] It is also due to the simple fact that long-term aspirin use is already widely practised among patients

for the prevention of cardiovascular events such as thrombo-sis and neurovascular events such as stroke thus providinga convenient opportunity for researchers to study its otherlong-term chemopreventive effects In fact major findings ofaspirinrsquos anticancer effects in humans are also derived fromclinical trial data originally compiled for the study of its anti-thrombotic effects [3 4] Aspirinrsquos affordability and ease ofaccess together with its relatively reduced side effects withrespect to other traditional NSAIDs [5] have also helped toincrease its appeal as a potential chemopreventive agent andtarget in anticancer studies

Nevertheless a considerable number of investigationshave shown that other NSAIDs including sulindac [6ndash8]indomethacin [9 10] ibuprofen [11 12] naproxen [13]and diclofenac [14ndash16] also exhibit significant antineoplasticbehaviour in mammalian cancer cells Additionally recentstudies have increasingly focused on the chemopreventiveproperties of a new NSAID class referred to as modifiedNSAIDs These are essentially traditional NSAIDs which caneither have nitric oxide- (NO-) donating moieties hydrogensulphide- (H

2S-) donating moieties or phosphate moieties

covalently attached to the ndashCOOH site via aromatic or

2 Oxidative Medicine and Cellular Longevity

aliphatic spacermolecules as shown in Figure 1The resultingmodified NSAID classes known as NO-donating NSAIDs(NO-NSAIDs) H

2S-donating NSAIDs (HS-NSAIDs) and

phospho-NSAIDs respectively have all been shown to befar less toxic than their NSAID precursors and several timesmore potent in terms of antineoplastic efficacy [17ndash22]The exceedingly potent anti-neoplastic properties of novelNSAID chimeras which are characterized by their pos-session of both NO- and H

2S-donating moieties (see Figure

1) have also begun to attract significant attention [23 24]The mechanistic pathways which mediate the anti-neo-

plastic effects of traditional andmodifiedNSAIDs are still notfully understood It has been postulated that the antiprolifer-ative effect of NSAIDs on malignant cells involves the inhibi-tion of proinflammatory COX activity [25] and prostaglandinformation [26] However additional evidence shows thatNSAIDs can induce apoptotic cell death in tumour cells [27]via pathways that are largely independent of COX [6 2829]The elucidation of apoptotic mechanisms underlying thechemopreventive effect of NSAIDs has long been the focus ofintense research using a broad range of experimental modelsincluding whole mammalian specimens human cancer celllines and Saccharomyces cerevisiae cells

11 Yeast Cells as a Model for the Study of the ProapoptoticEffects of NSAIDs Yeast cell species such as Saccharomycescerevisiae are among the preferred and extensively usedexperimental models for the study of programmed celldeath associated with ageing disease and cancers in livingorganisms This is partly because yeast cells retain many coreelements of mammalian cell processes such as apoptosis [30]Additionally these primitive eukaryotes have a number ofimportant advantages over complex mammalian cell modelsYeast cells are relatively inexpensive and easy to handle witha relatively brief lifespan that permits rapid generation ofexperimental results in a shorter span of time Moreover theyeast cell genome is verywell characterised and relatively easyto manipulate allowing for the ready availability of yeastmutant strains for experimental studies Overall these fea-tures collectively account for the successful use of buddingyeast as a model organism for the study of molecular path-ways underlying mammalian pathologies such as cancer

These same advantages of the yeast cell experimentalmodel also account for its wide use in the study of proapop-totic pathways underlying the anti-neoplastic behaviour ofantitumour drugs such as paclitaxel bleomycin valproateand arsenic [31] These compounds have been studied exten-sively in yeast cells in an effort to improve anticancerstrategies in human patients Likewise S cerevisiae buddingyeast cells have also been used to study the growth inhibitoryproapoptotic effects of NSAIDs such as aspirin [32] anddiclofenac [33]

The study of the proapoptotic effects of NSAIDs in yeastmodels is still a relatively new concept with far fewer studieshaving been carried out in yeast with respect to mammaliancells Regardless evidence acquired thus far from yeaststudies of NSAIDs such as aspirin has already yielded valu-able insights into their proapoptotic behaviour highlighting

Table 1 Human cancer cell targets of the proapoptotic effects ofprominent traditional and modified NSAIDs

NSAID type Target cell type [references]Traditional NSAIDs

Aspirin

Colon cancer cells [34ndash36] leukaemia cells[37 38] cervical cancer cells [39 40]gastric cancer cells [41ndash44] hepatocellularcarcinoma cells [45 46] endometrialcancer cells [29] neuroblastoma cells [47]

Indomethacin Colon cancer cells [7 35] Gastric cancercells [44] Endometrial cancer cells [29]

SulindacColon cancer cells [6 7 48 49] prostatecancer cells [48] hepatocellular carcinomacells [8] lung cancer cells [50]

Ibuprofen Colon cancer cells [51]

Diclofenac Neuroblastoma cells [15] melanoma cells[16]

Tolfenamic Acid Prostate cancer cells [52]

Modified NSAIDs

NO-Aspirin Pancreatic cancer cells [53] colon cancercells [17 54ndash58]

NO-sulindac Colon cancer cells [17] melanoma cells[59]

NO-ibuprofen Colon cancer cells [17]NOSH-aspirin Colon cancer cells [24]

Phosphoaspirin Colon [19 21 56] pancreatic [21] andbreast [21] cancer cells

Phosphosulindac Colon pancreatic and breast cancer cells[21]

HS-aspirin Colon cancer cells [22] breast cancer cells[60]

HS-ibuprofen Colon cancer cells [22]HS-naproxen Colon cancer cells [22]HS-sulindac Colon cancer cells [22]

factorswhich play key roles inNSAID-induced death (such asreactive oxygen species (ROS) and mitochondrial dysfunc-tion) In fact compelling evidence has shown that S cerevisiaecells constitute a powerful model for the screening and devel-opment of NSAIDs and other proapoptotic drugs designedfor use in human cancer patients overcoming the problem ofcell specificity in the design of antitumour compounds [31]whilst also serving as an inexpensivemodel to initially test theeffect of antitumour drugs before assaying them in more rel-evant mammalian systemsTherefore yeast cells clearly servean important role as a complementary experimentalmodel tomammalian cells in the study and elucidation of NSAID-induced mechanisms of apoptosis

In this review important biomolecular pathways trig-gered by traditional and novel NSAIDs which lead to theinduction of apoptosis in mammalian cell lines and in S cere-visiae yeast cells will be discussed The significance of theseproapoptotic mechanisms in the context of the role NSAIDsmay play in the design of more effective cancer preventionstrategies is also considered

Oxidative Medicine and Cellular Longevity 3

Sulindac Phosphosulindac

IbuprofenHS-ibuprofen

Aspirin NO-aspirin

NOSH-aspirin

H3C

S

O

CH3

OH

F

O

O

S

OH

Ominus

N+

CH3

CH3

H3C

OH

O

O

H3C

O

SS

O

OO

O

H3C

O

O

O

O

O ON+

Ominus

H3C

CH3

CH3

O

O

S S

S

O O

OO

P

O

O

CH3

F

H3C S

H3C

CH3

O

O

Figure 1 Chemical structures of modified NSAIDs and their traditional NSAID precursors Phosphosulindac which exemplifies phospho-NSAIDs consists of the sulindac molecule linked at the ndashCOOH site to a phosphate group via an aliphatic spacer molecule (both shown ingreen) In the HS-NSAID known as HS-ibuprofen an aromatic spacer molecule links an H

2S-releasing dithiolethione group (both shown in

red) to the ibuprofen structure Similarly the NO-NSAID NO-aspirin is composed of an NO-releasing-NO2group and an aromatic spacer

molecule (both shown in blue) which is linked to the ndashCOOH group of aspirin Finally the modified NSAID chimera known as NOSH-aspirin is characterized by the aspirin structure linked via two separate spacer molecules to both a H

2S-releasing moiety (shown in red) and

an NO-releasing moiety (shown in blue)


2 NSAID-Induced COX Inhibition andApoptotic Cell Death

The cyclooxygenase isoforms COX-1 and COX-2 both ofwhich are key requirements for the synthesis of prostaglan-dins in mammalian cells constitute the best defined phar-macological targets of NSAIDs such as aspirin [61 62] Thusit has long been postulated that the chemopreventive effectof NSAIDs is mediated by their ability to inactivate COX-enzymes causing inhibition of prostaglandin synthesis andconsequent suppression of both tissue inflammation andcell proliferation two conditions heavily associated withtumour formation [25] In fact both prostaglandins andCOXenzymes particularly COX-2 are implicated in tumorigene-sis [1 2 63 64] and have been observed in high quantities inseveral types of human tumours including colorectal carci-nomas [65ndash69] Moreover prostaglandins such as PGE

2are

known to promote angiogenesis alter cellular immunityincrease both proliferation and invasiveness of cells andenhance cellular resistance to apoptosis [2 68 70]

It has been shown that deletion of receptors for PGE2

confers resistance to both polyp and cancer formation [71]Similarly disruption of COX-2 activity was found to reducethe incidence of polyp [72 73] and aberrant crypt fociformation [74] in the intestines of rodent models Inhibitionof COX-2 has also been shown to be effective in preventingthe formation of human colorectal adenomas [75 76] andoesophageal squamous cell carcinoma [64] Thus inhibitionof COX-2-dependent prostaglandin synthesis is thought tomediate at least in part the tumour-suppressive antiprolif-erative effects of NSAIDs such as the suppression of angio-genesis and the induced lowering of resistance to apoptosisIn fact inhibition of invasive tumour formation in NSAID-treatedmousemodels has been associatedwith decreased cel-lular levels of PGE

2[26]

The anti-neoplastic behaviour of NSAIDs is also associ-ated with their ability to actively induce apoptosis in malig-nant cells However the means by which COX-2 inhibitioncould possibly mediate NSAID-induced cancer cell apoptosishas long been the subject of debate [77 78] As suchthere is no clear evidence implicating direct involvement ofprostaglandins in NSAID-induced apoptosis which suggeststhat prostaglandins do not directly mediate NSAID-induceddeath [77ndash79] In fact studies have indicated that aspirin-induced apoptosis in mouse [80] and human [81] cancer cellscan occur independently of prostaglandin inhibition Sim-ilarly Chan and coworkers [7] demonstrated that apopto-sis induced by sulindac and indomethacin in mammalianHCT116 and SW480 colon cancer cell lines did not depend onprostaglandin depletion since supplementation of these samecells with prostaglandins failed to protect them from apopto-sis However this same study did present evidence of COX-2-dependent apoptosis induced by these NSAIDs The authorssuggested that cellular accumulation of the prostaglandinprecursor arachidonic acid brought about by the NSAID-induced inhibition of COX-2 caused cancer cell apopto-sis by stimulating sphingomyelinase-mediated synthesis ofceramide [7] which is a proapoptotic molecule [82] Arachi-donic acid accumulation in cancer cells also induces ROS

accumulation [83] mitochondrial permeability transitionand cytochrome c release [84] all of which lead to apoptoticcell death

3 COX-Independent NSAID-InducedApoptotic Cell Death

The proapoptotic effects underlying the chemopreventivepotential of NSAIDs cannot be accounted for by COXinhibition alone Firstly NSAIDs have been shown to inhibitproliferation and induce apoptosis in malignant cell lineswhich do not express either COX-1 or COX-2 as observedin cyclooxygenase-null mouse embryo fibroblasts [85] andhuman colon cancer cells [28 81 86] Furthermore NSAIDcompounds which cannot inactivate COX-2 such as sulindacsulfone a metabolite of sulindac [87] have been shown toinduce apoptosis of gastric tumour cells [88] and inhibit colontumour formation in rodents [89 90] Additionally NSAIDconcentrations required to induce apoptosis in cancer cellshave often been found to be significantly higher than thatrequired to inhibit COX-2 suggesting the presence of alterna-tive cellular targets of NSAIDs [27 37 77 91] Indeed numer-ous studies have shown that NSAID-induced apoptosis inmammalian tumour cells can be mediated by several largelyCOX-independent metabolic pathways the most prominentof which are presented in the following discussion

31 Activation of Caspases and Modulation of Bcl-2 ProteinsNSAIDs can mediate apoptosis by inducing the activationof caspases a family of proapoptotic cysteine proteinaseenzymes which typically exist as latent zymogens in cellsActivation of these proteins by proapoptotic signals initiatesa caspase cascade whereby initiator caspases specifically acti-vate other executioner-type caspases The latter then degrademultiple cellular components so that cells begin to acquire themorphological and biochemical features of apoptosis [92]Bellosillo and coworkers [37] were among the first to presentevidence of NSAID-induced caspase activationThey showedthat B-chronic lymphocytic leukemia (B-CLL) cells treatedwith high doses of aspirin underwent apoptosis characterisedby DNA fragmentation and degradation of poly (ADP-ribose) polymerase (PARP) which is a caspase substrateThe apoptotic phenotype was inhibited by application of thepan-caspase inhibitor Z-VAD-FMK thus confirming theinvolvement of caspases in aspirin-induced B-cell apoptosisSimilarly Castano and coworkers [34] affirmed caspaseinvolvement in aspirin-induced apoptosis of HT-29 humancolon adenocarcinoma cells However contrary to its effectin B cells aspirin did not induce PARP degradation in HT-29cells This observation is probably one of the earliest to sug-gest that NSAID-induced activation of caspases can occur viadifferent pathways

Indeed it has since been shown that NSAIDs activate cas-pases both via the mitochondrial-mediated (intrinsic) path-way which involves mitochondrial cytochrome c release andsubsequent activation of caspase 9 and via the death-receptormediated (extrinsic) pathway which involves the activationof caspase 8 [41] Proapoptotic NSAID-induced activation


of caspases mediated by the early release of mitochondrialcytochrome c in mammalian cancer cells has clearly beendemonstrated by studies such as that of Pique et al [38] Theauthors reported that cytochrome c release preceded both thedisruption of the mitochondrial membrane potential (ΔΨ119898)and the activation of caspases The latter observation wasconfirmed by Zimmermann and coworkers [39] who in turnshowed that in aspirin-induced apoptosis of human cancercells the release of mitochondrial cytochrome c was itselftriggered by translocation of proapoptotic Bax protein to themitochondria Conversely overexpression of antiapoptoticBcl-2 protein inhibited both cytochrome c release and apop-tosis of aspirin-treated cancer cells Furthermore deletion ofapoptotic protease-activating factor-1 (APAF-1) a cytosolicmolecule which mediates caspase 9 activation after bindingto mitochondrial cytochrome c rendered cells resistant toaspirin-induced apoptosis These observations indicate thatcytochrome c release is a critical mediatory mechanism ofapoptotic cell death induced by NSAIDs [39] In fact it hasalso been shown that aspirin-induced apoptosis of S cere-visiae cells deficient in manganese superoxide dismutase(MnSOD) and cultivated in nonfermentable ethanolmediumis preceded by the early release of cytochrome c followed bya drastic fall in ΔΨ119898 [93]

Extrinsic activation of caspase 8 is also an importantmediator of NSAID-induced cancer cell apoptosis [42 48]Activated caspase 8 can initiate apoptosis by activating down-stream caspases or by cleaving the BH3-domain only proteinBid Truncated Bid (tBid) can translocate to themitochondriato trigger cytochrome c release [94 95] and can also activateBax [96] Indeed aspirin-induced apoptosis of AGS gastriccancer cells was marked by activation of caspase 8 and Bidcleavage along with the mitochondrial translocation of Baxactivation of downstream caspases and cleavage of PARPSpecific inhibition of caspase 8 abrogated cleavage of both Bidand PARP and prevented aspirin-inducedAGS cell apoptosisthus implicating extrinsic caspase activation in the initiationof aspirin-induced apoptosis [42] However in this samestudy the release of cytochrome c and activation of caspase9 were also observed thus suggesting the involvement evenof mitochondrial-mediated caspase activation In fact severalother studies have since shown that the chemopreventiveapoptotic effect of aspirin [41 43 45 46] and modifiedNSAIDs such as NO-aspirin [97] and phosphosulindac [20]onmammalian cancer cells may involve the initiation of bothintrinsic and extrinsic caspase activation pathways whichoperate in parallel to one another

The ability of NSAIDs to activate caspases largely explainsthe profound influence they have on Bcl-2 proteins suchas Bax Bid and Bcl-2 [42 43] the expression and cellulardistribution of which can be greatly altered by NSAIDs tomediate apoptosis in cancer cells NSAIDs such as aspirinand indomethacin have long been shown to induce cancercell apoptosis by upregulating the expression of proapoptoticBcl-2 proteins such as Bax and Bak and by downregulatingexpression of anti-apoptotic Bcl-2 proteins such as Bcl-2 andBcl-XL [29 44] More recent work has shown that NSAID-induced downregulation of Bcl-XL can be induced in part byproteasome-mediated protein degradation [98]

NSAID-induced intrinsic and extrinsic activation of cas-pases along with modulation of Bcl-2 protein expression allseem to converge at the mitochondria Here these pathwaysinduce events such as the release of cytochrome c and otherproapoptotic molecules including SMACDiablo from themitochondria [43] which irreversibly commit cells to the fullapoptotic phenotype Thus mitochondria clearly constitutea very important target of NSAID-induced apoptosis asindicated by the many studies associating NSAID-inducedapoptosis of mammalian cells with mitochondrial dysfunc-tion such as uncoupling of oxidative phosphorylation [99]inducedmitochondrial permeability transition [100 101] andinactivation of mitochondrial enzymes such as aconitase andrespiratory chain proteins [45]

Likewise it has been shown that the mitochondria of Scerevisiae cells constitute a critical target of NSAIDs such asaspirin [32] the proapoptotic effects of which were shown tobe associated with inhibition of the electron transport chain[93] Similarly Van Leeuwen and coworkers [33] observedthat growth inhibition and apoptosis of S cerevisiae cellscaused by treatment with the NSAID diclofenac were due tomitochondrial dysfunctional events involving the inhibitionof the electron transport chainThe fact that yeast cells whichare primitive eukaryotes share a common mitochondrialtarget of NSAIDs with mammalian cells is highly significantbecause it suggests that mitochondria constitute a unifyingdominant target of NSAID-induced apoptosis in all mam-malian cancer cell types This may certainly help informthe design of more effective NSAIDs for chemopreventivepurposes and illustrates the important contribution of yeastcells as a complementary experimental model for the study ofNSAID-induced apoptotic mechanisms

32 Depletion of Polyamines Polyamines such as sperminespermidine and putrescine are abundant polycations foundin all eukaryotic cells and play an essential role in cellulardevelopment and proliferation [102] High polyamine levelsare in fact associated with the induction of cell proliferation[103 104] whilst lowered polyamine levels have been foundto promote cell growth inhibition [105] and apoptosis [106]Hence it is no surprise that the polyamine content of cancercells tends to be significantly higher than that of normal cells[102] thus representing a potential target of anti-neoplasticagents such as NSAIDs a number of which have been showntomediate their chemopreventive effect by promoting the cat-abolic degradation of polyamines in cancer cells [35 49 107]This takes place by virtue of the general ability of NSAIDsto modulate cellular polyamine metabolism which is reg-ulated by the biosynthetic enzyme ornithine decarboxylase(ODC) and the catabolic polyamine-acetylating enzymespermidinespermine N1-acetyltransferase (SSAT) [49 107]For instance indomethacin-induced growth inhibition ofhuman colon cancer cells has been shown to be associatedwith downregulation of ODC activity and upregulation ofSSAT activity which concurrently impair the synthesis ofpolyamines and increase the rate at which they are degradedThe consequent depletion of cellular polyamines was accom-panied by apoptotic cell death [35] Other traditionalNSAIDs


such as aspirin [108] sulindac sulfone [49] and ibuprofen[107] mainly induce the enhanced degradation and exportof polyamines by upregulating gene expression of SSAT incancer cells resulting in reduced proliferation and increasedapoptosisThis is also true of modifiedNSAIDs such as phos-phosulindac [20] the antiproliferative proapoptotic effectof which can like its NSAID precursor sulindac [109] beenhanced even further by concurrent treatment of cells withODC inhibitors such as difluoromethylornithine (DFMO)[20 110 111] Both DFMO and phosphosulindac act syner-gistically to enhance the depletion of polyamines in coloncancer cells strongly inhibiting their proliferation and greatlyenhancing apoptosis [20]

33 Modulation of NF-120581B Activity Nuclear factor kappa B(NF-120581B) is a ubiquitous cellular transcription factor whichregulates the expression of genes associated with inflam-mation immune responses cell growth differentiation andapoptosis Composed of p65 (RelA) and p50 polypeptidesthis complex transcription factor is sequestered in an inactiveheterodimeric form within the cell cytoplasm by I kappaB alpha (I120581B120572) or beta (I120581B120573) inhibitor proteins [112 113]Stimulation by appropriate signals (such as proinflammatorycytokines including tumour necrosis factor (TNF)) triggersthe IK120572 or IK120573 kinase- (IKK-) mediated phosphorylationof I120581B proteins which consequently undergo ubiquitin-dependent proteasomal degradation This permits transloca-tion of NF-120581Bmolecules to the nucleus where they then bindto and promote the transcription of numerous target genesbearing a 120581B-binding motif [79 113 114]

The constitutive activation of NF-120581B is a hallmark of sev-eral types of cancers [115ndash117] and is heavily associated withcancer cell resistance to cytotoxic agents due in part to itsinduced upregulation of anti-apoptotic proteins [118] ThusNF-120581B constitutes yet another potential target of chemother-apeutic agents such as NSAIDs which can modulate NF-120581Bsignalling in cancer cells to promote the onset of apoptosis[36 54 60 107 111 114 119]

Traditional NSAIDs such as aspirin have been reportedto inhibit NF-120581B activation by preventing the degradation ofI120581B [119] Aspirin can inhibit TNF-induced I120581B120572 degrada-tion [120] by modulation of p38 mitogen-activated protein(MAP) kinase pathways [121] and by disrupting the ubiquitin-dependent proteasomal pathway of which I120581B120572 is a substrate[47] Aspirin can also block I120581B120573 degradation throughcompetitive inhibition of IKK120573-ATPmolecular binding thusfacilitating selective inhibition of IKKkinase (IKK120573) [114] Allthese mechanisms prevent NF-120581B activation and subsequenttranscription of anti-apoptotic proteins It has also beenshown that the NSAID sulindac specifically inhibits IKK120573activity and NF-120581B activation in cancer cells thus promotingapoptosis [122] Likewise the growth inhibitory effect ofNSAIDs such as ibuprofen [51] indomethacin and etori-coxib a recently developed COX-2 inhibitor [117] is associ-ated with their inhibition of NF-120581B signalling in cancer cells

The growth inhibitory effect mediated by modifiedNSAIDs such as NO-NSAIDs on various cancer cell linesalso involves the modulation of NF-120581B signalling [54 55]The growth inhibitory effect of NO-aspirin associated with

its ability to reduce proliferation and enhance apoptosis ofcancer cells was shown to be significantly correlated to itsprofound inhibition of the NF-120581B signalling pathway theoccurrence of which was suggested to be due to inhibitionof NF-120581B binding to DNA in the nucleus [55] Sun and Rigas[56] went on to demonstrate that proapoptotic inhibition ofNF-120581B signalling in human colon cancer cell lines treatedwith NO-aspirin stemmed from the latterrsquos induced gener-ation of reactive oxygen and nitrogen species (RONS) whichmay have interacted directly or indirectly (via the redox-sensitive thioredoxin (TRX) system) with NF-120581B impairingits ability to bind to recognition DNA sequences in thenucleus This is highly conceivable given that NF-120581B tran-scriptional activity is sensitive to redox changes [123] In factit has since been shown that structurally diverse NO-NSAIDssuch as NO-aspirin and NO-naproxen can suppress NF-120581Bsignalling in cells via S-nitrosylation of the NF-120581B transcrip-tion factor This redox-signalling mechanism is mediated bythe released NO group which on binding to the p65 mono-mer of NF-120581B impairs the transcription factorrsquos ability tobind to DNA [57] The redox-induced inhibition of NF-120581B signalling is thought also to partly mediate the growthinhibitory effect (including apoptosis cell cycle arrest andinhibition of proliferation) of phospho-NSAIDs [19 21 111]and HS-NSAIDs in cancer cells [60]

Intriguingly the effect of NSAIDs on NF-120581B activityseems to be cell-type specific since aspirin-induced apoptosisof HCT 116 colon cancer cells was shown to be mediated bythe activation of NF-120581B signalling rather than its inhibition[36] Additionally Din and coworkers [124] observed thataspirin-induced I120581B120572 degradation activation of NF-120581B sig-nalling and apoptosis took place in colorectal cancer cells butnot in other malignant cell types Loss of cellular I120581B120572 whichis indicative of NF-120581B activation has also been reportedin aspirin-induced apoptosis of both immortalised humanendothelial cells [125] and animalmodels of human colorectalcancer [126] Likewise Babbar and coworkers [107] observedthat aspirin caused the activation of NF-120581B signalling inCaco-2 colon cancer cells suggesting even that this eventwas responsible for the upregulation of SSAT expression andpolyamine depletion which led to apoptosis Besides aspirinother traditional NSAIDs such as diclofenac have also beenreported to induce activation of NF-120581B signalling as a meansto attenuate cancer cell proliferation and promote apoptosis[127] It has been argued that the varying effects ofNF-120581Bmaybe due to the specificity by which this transcription factorbinds to DNA and activates target genes Such specificity isin turn dependent on the dimeric composition of the NF-120581B complex and on the transcriptional cofactors that it hasrecruited both ofwhich can vary depending on the kinetics ofinduction [128] Therefore different stimuli or even the samestimulus exerted under different conditions can induce dif-ferent NF-120581B complexes and different downstream responses[36 107]

34 Modulation of MAP-Kinase Activity Mitogen activatedprotein (MAP) kinases are serinethreonine-specific proteinswhich respond to extracellular stimuli and regulate various


cellular pathways including mitosis cell proliferation sur-vival and death [129] The three principal MAP kinasesubgroups include the extracellular signal-regulated kinasesERK12 (p42p44) c-Jun N-terminal kinasesstress-activatedprotein kinases (JNKsSAPKs) and the p38 MAP kinases[121] NSAIDs such as aspirin and its metabolite salicylatehave long been shown to modulate MAP kinase signallingin mammalian cells [130 131] This is exemplified by thesalicylate-induced activation of p38MAP kinase signalling inFS-4 fibroblasts which induced apoptosis [130] via a pathwayinvolving theNSAID-induced inhibition of I120581B120572degradationand NF-120581B signalling [121] Based on these observations theauthors concluded that apoptotic cell death induced by p38MAP kinase activation played an important role inmediatingthe anti-neoplastic effects of NSAIDs The important medi-atory role of MAP kinase modulation in the context of theanti-neoplastic effects of NSAIDs was further highlighted byJones and coworkers [132] who demonstrated that NSAID-induced inhibition of angiogenesis involved the disruptionof ERK12 kinase signalling a typically prosurvival path-way [133] Additionally inhibition of ERK12 signalling wasshown to be the mechanism by which aspirin sensitiseshuman cervical cancer cells to apoptosis induced by tumournecrosis factor-related apoptosis-inducing ligand (TRAIL)[40] Modulation of MAP kinases has also been implicatedin the suppressive effect of certain NSAIDs such as aspirinupon the factor activator protein (AP-1) a downstream targetof MAP kinases which is critical for inducing neoplasia andactivation of genes associated with inflammation and infec-tion [134]

The modulation of MAP kinases has been shown to becritical for the growth inhibitory effect of modified NSAIDssuch as NO-aspirin [135] Aside from its propensity to inhibitNF-120581B signalling NO-aspirin was shown to induce theactivation (marked by increased phosphorylation) of all threemain MAP kinases in a concentration-dependent mannerin colon cancer cells This was caused by the NO-aspirin-induced generation of RONS and subsequent oxidation ofcellular thioredoxin-1 protein (Trx1p) which facilitated theproapoptotic autophosphorylation and activation of ASK1 aprotein involved in the MAP kinase cascade and only keptinactive when attached to reduced Trx1p [56] The sameauthors implicated ASK1-Trx1p cleavage in the activation ofMAP kinase signalling which in turn partly mediated thegrowth inhibitory effect of NO-aspirin an effect markedby increased apoptosis and inhibition of cell proliferationLikewise NO-aspirin-induced cell cycle arrest and apoptosisof pancreatic cancer cells has been shown to occur via ROS-mediated modulation of all three MAP kinase signallingpathways and their downstream effector molecules such asp21 and cyclin D1 [53] The rapid response of MAP kinasesto the presence of RONS is not surprising given their well-established redox sensitivity [136] The modulation of MAPkinase pathways was also implicated in the chemopreventiveeffect of NO-sulindac on UVB-induced melanoma cells [59]and in phospho-NSAID-mediated redox-dependent apopto-sis of colon cancer cells [19 111]

35 Inhibition of Wnt120573-Catenin Signalling The Wnt sig-nalling pathway regulates the biosynthesis of 120573-catenina protein which is required for cell-to-cell adhesion andinvolved in the expression of genes associated with cancer[137] Constitutive activation ofWnt120573-catenin signalling hasbeen implicated in the development of numerous humanmalignancies [138ndash143] AberrantWnt120573-catenin signalling isassociated with the nuclear accumulation of 120573-catenin andthe subsequent activation of the transcription factor knownas T-cell factor (TCF) The resulting 120573-cateninTCF complexpromotes the transcriptional activation of target genes associ-ated with proliferation such as cyclin D1 [144 145] hence theimplicated role of Wnt120573-catenin signalling in human car-cinogenesis

The NSAIDs aspirin and indomethacin have been shownto attenuate Wnt120573-catenin signalling in colorectal cancercells in a dose-dependent manner by inhibiting the tran-scription of 120573-cateninTCF-responsive genes This NSAID-induced inhibition did not involve cleavage of the 120573-cate-ninTCF complex but rather the hyperphosphorylation andconsequent stabilization of 120573-catenin presumably caused bythe inactivation of a phosphatase enzyme [146 147] Furtherstudies have since shown that aspirin-mediated downregula-tion of Wnt120573-cateninTCF signalling can indeed be medi-ated by its induced inactivation of protein phosphatase 2A[148] but also in part by the downregulation of upstreamspecificity protein (Sp) transcription factors [149] OtherNSAIDs such as sulindac can also mediate the antiprolifera-tive degradation of 120573-catenin in cancer cells partly by protea-somal degradation and partly by caspase-mediated cleavage[150] whilst others such as diclofenac have been shown tosuppress Wnt120573-cateninTCF signalling via the activation ofNF-120581B [127]

The downregulation of Wnt120573-cateninTCF signallinginduced by NSAIDs has been associated with the profoundgrowth inhibition of various cancer cell types in a mannerthat seems in large part to be due to inhibition of cell prolif-eration rather than by direct induction of apoptosis [127 142146 150 151] However the proapoptotic effect of NSAIDssuch as sulindac [152] in colorectal cancer cell lines has beenshown to involve downregulation ofWnt120573-cateninTCF sig-nalling FurthermoreWnt120573-catenin signallingwas observedto play a key role in directly mediating the proapoptoticeffect of aspirin in human mesenchymal stem cells [153]Regardless the high prevalence of 120573-catenin downregulationreported in studies of NSAID-induced growth inhibition ofcancer cells underlines the importance of this pathway as achemopreventive target of NSAIDs

This is certainly true for modified NSAIDs such as NO-aspirin the growth inhibitory effect of which is strongly asso-ciated with a number of induced cellular events including theprofound concentration-dependent inhibition of 120573-cateninsignalling in colon cancer cells [54 58 145 154] In thisregard NO-aspirin is far more effective than aspirin in thatat concentrations far below those required for the inhibi-tion of cell proliferation it actually prevented formation ofthe 120573-cateninTCF complex whereas aspirin did not [145]Moreover at higher concentrations NO-aspirin can inducecaspase-3-mediated cleavage of 120573-catenin itself leading to


a significant decline of cellular 120573-catenin levels and loss ofcell-to-cell adhesion amongst colon cancer cells [58]The sig-nificant downregulation of Wnt120573-catenin signalling medi-ated at least in part by caspase-mediated 120573-catenin degrada-tion has also been implicated in the growth inhibitory effectof NO-aspirin on leukaemia [97] and breast cancer cell lines[155] The same applies for phospho-NSAIDs such as phos-phosulindac the growth inhibitory effect of whichwas shownto involve 120573-catenin degradation in breast cancer stem cells[156]

36 Oxidative Stress and Disruption of Redox BalanceNSAIDs can mediate apoptosis in both malignant cell linesand budding yeast cells by upregulating the generation ofROS and by inducing oxidative stress Indeed it has beenargued that ROS generationmay constitute a central unifyingmechanism by which the anti-neoplastic effects of NSAIDsaremediated given that oxidative stress is coupled withmanyproapoptotic signals such as NF-120581B inhibition and MAPkinase activation [157 158] The fact that ROS accumulationalsomediates NSAID-induced apoptosis in primitive eukary-otes such as yeast [33] further corroborates this argumentHowever the cellular prooxidant behaviour of NSAIDs hasoften been the subject of controversy due to conflictingreports that NSAIDs such as indomethacin and sulindac [159160] scavenge ROS and exert a cytoprotective antioxidanteffect in cells Likewise there are numerous reports derivedfrom in vivo studies of rats showing that NSAIDs such asaspirin can exert a cytoprotective antioxidant effect associ-ated with the attenuation of ROS [161 162] and of lipid perox-idation [163 164] alongwith the upregulation of antioxidantssuch as reduced glutathione (GSH) [165] and superoxide dis-mutases (SODs) [166] It has also been shown that low dosesof aspirin can confer long-term cytoprotective resistanceagainst H

2O2-induced oxidative stress in S cerevisiae cells

[167]Nevertheless other investigations have clearly shown that

NSAIDs can induce the proapoptotic accumulation of ROSin both yeast [33] and mammalian cells [157] For instanceapoptotic cell death of respiring S cerevisiae cells cultivated inthe presence of diclofenac was clearly linked to a significantincrease in cellular ROS as measured by the ROS-sensitivefluorescent probe 2101584071015840-dichlorodihydrofluorescein diacetate(DCDHF-DA) [33] Similarly indomethacin-induced apop-tosis of gastric epithelial cells which was abrogated aftertreatment with antioxidants such as N-acetylcysteine (NAC)was shown to require the generation of ROS [168] anevent likewise implicated in the proapoptotic depletion ofpolyamines induced by indomethacin in colorectal cancercells [35] Additionally Chan and coworkers [7] showedthat human colorectal cancer cell apoptosis induced by bothindomethacin and sulindac was marked by the accumulationof arachidonic acid an event which is itself heavily associatedwith the accumulation of cellular ROS [83 169]The accumu-lation of ROS was also shown to be a critical inducer of mito-chondrial cytochrome c release disruption of ΔΨ

119898 caspase

activation and apoptosis in salicylate-treated mammaliantumour cells [170] Additionally the NSAID sulindac and

its metabolites have been shown to enhance the antitumoureffect of the proteasome-inhibitor bortezomib primarilythrough the synergistic generation of ROS [171] It has beensuggested that conflicting reports of NSAID redox behaviourin eukaryotic cells might simply be due to differences in thetiming of measurements of ROS and antioxidant changesin experimental setups given that cellular antioxidant levelsare naturally expected to increase in subsequent response toelevated ROS [157]

The molecular mechanisms underlying NSAID-inducedproapoptotic generation of ROS in mammalian and yeastcells have not yet been fully elucidated However it is wellknown that mitochondria a major source of cellular ROS[172] and a central component of the apoptotic machineryare profoundly affected by NSAIDs in both yeast [33 93]and mammalian cells [99 101] For example the aspirinmetabolite salicylate has been shown to inhibit the mito-chondrial electron transport chain in mammalian cells byinteracting with an Fe-S cluster of Complex I through its o-hydroxyl groupThis was found to induce ROS accumulationand oxidative stress which in turn caused proapoptoticevents such as mitochondrial permeability transition andcytochrome c release [173] Likewise aspirin-induced cellcycle arrest and apoptosis of HepG2 hepatoma cells wereshown to be induced by ROS accumulation and increasedoxidative stress accompanied by severe mitochondrial dys-function such as the inactivation of electron transport chainproteins and aconitase [45] Van Leeuwen et al [33] observedthat reduced cell growth and viability of S cerevisiae yeastcells treated with diclofenac are due to mitochondrial dys-function associated with the inhibition of electron transportchain subunit proteins Rip1p (of Complex III) and Cox9p(of Complex IV) This caused inhibition of cell respirationand subsequent ROS production resulting in cell deathInhibition of cellular respiration induced by aspirin wasalso observed in MnSOD-deficient yeast cells cultivated inethanol medium [93] and recent studies in our laboratoryhave established the aspirin-induced proapoptotic generationof mitochondrial superoxide radicals in these cells (unpub-lished work)

It has been shown that the proapoptotic induction ofoxidative stress induced byNSAIDs such as aspirin is stronglyassociatedwith themodulation of cellular redox homeostasisThis is exemplified by the observed increase of aspirin-induced apoptosis in HepG2 cells with GSH depletion andcompromised redox balance [174] In addition to this studiesin S cerevisiae yeast cells have shown that aspirin-treatedMnSOD-deficient yeast cells grown in ethanol mediumexperienced a very significant decrease in cellular reducingpower with respect to wildtype cells as measured by theNADPHNADP+ concentration ratioThis was accompaniedby a significant decrease of the GSHGSSG concentrationratio owing to a buildup of GSSG prior to cell death [175]

The induction of oxidative stress mediated by disruptionof cellular redox balance is also central to the apoptotic effectof modified NSAIDs in cancer cells [53 56 58 158] Forinstance oxidative stress induced by NO-aspirin in coloncancer cells was shown to be mediated by the depletion ofcellular GSH caused by the latterrsquos associationwith the spacer


component of NO-aspirin and subsequent formation of aGSH conjugate The resulting redox imbalance then initi-ated a number of downstream proapoptotic pathways suchas 120573-catenin cleavage inhibition of Wnt signaling andmitochondrial-mediated activation of caspases [58] Sun andRigas [56] further demonstrated that redox-induced apopto-sis of colorectal cancer cells treated with NO-aspirin involvedthe generation of RONS the growth inhibitory effect of whichwas mediated by oxidative alteration and impairment of thethioredoxin redox system Oxidised thioredoxin-1 inducedMAP kinase activation and NF-120581B inhibition both of whichare criticalmediatory pathways ofNO-aspirin-induced apop-tosis [55 135]

Oxidative stress marked by RONS accumulation andredox imbalance associated with the suppression of GSHand increased oxidation of Trx-1 also plays a central role inapoptosis induced by phospho-NSAIDs [19ndash21 56 110 111]Like NO-NSAIDs the strong prooxidant effect exerted byphospho-NSAIDs is reported to set in motion a pleiotropiccascade of redox-sensitive signalling events including acti-vation of MAP kinases and inhibition of NF-120581B signalling[19 21 56] along with the depletion of cellular polyaminesat least in the case of phosphosulindac [20 110 111] Thecollective initiation of all these antiproliferative proapoptoticpathways accounts for the very potent growth-inhibitoryeffects of phospho-NSAIDs with respect to their traditionalNSAID precursors [111] Likewise recent studies have shownthat both apoptosis and cell cycle arrest of cancer cells treatedwith HS-NSAIDs such as HS-aspirin are induced as a resultof oxidative stress and redox imbalance [60]

37 Other NSAID-Induced Proapoptotic Pathways Furthermechanisms by which NSAIDs can promote apoptosis inmalignant cells include the induced depletion of survivinan inhibitor of apoptosis protein which regulates the cellcycle and apoptosis in eukaryotic cells Survivin expressionin cancers tends to be very high and is in fact associated withtumour cell chemoresistance making it an attractive targetof antineoplastic treatments [176] including NSAIDs Lu andcoworkers [177] showed that aspirin caused significant andtargeted depletion of survivin in breast cancer cells by upreg-ulating its proteasomal degradation consequently sensitizingthe tumour cells to TRAIL-induced apoptosis Moreoveraspirin acted synergistically with TRAIL to promote apop-tosis of the breast tumour cells Similarly it has been shownthat cell cycle arrest and apoptotic cell death induced by theNSAIDs ibuprofen [51] and tolfenamic acid [52] in humancolon and prostate cancer cells respectively are accompaniedby significant depletion of survivin levels

Another COX-independent proapoptotic pathway in-duced by NSAIDs is the impairment of proteasome func-tion as demonstrated by Dikshit and co-workers [47] whoobserved a time- and dose-dependent decline of proteasomalactivity in neuroblastoma cells treated with aspirin Accom-panied by the accumulation of ubiquitylated proteins andprofound mitochondrial abnormalities the aspirin-inducedimpairment of proteasomal function was shown to activatethe intrinsic apoptotic pathway marked by a release of cyto-chrome c and the activation of caspase 9

Finally NSAIDs such as sulindac have been reported toinduce sensitization of cancer cells to mda7IL24-mediatedapoptosisThemda7 gene also known as IL24 is of the inter-leukin (IL) 10 family of cytokines [178 179] Ectopic expres-sion of mda7 is known to exert a potent tumour-suppressiveeffect against a variety of human cancer cells with little to noeffect on normal cells [180ndash182] Furthermore intratumouraladministration of adenoviral vectors which express mda7(Ad-mda7) has been shown to exhibit antitumour and antian-giogenic activity in human lung tumour xenografts [183]Also Oida and coworkers [50] demonstrated that Ad-mda7-mediated growth inhibition and apoptosis of human lungcancer cells was greatly enhanced by concurrent adminis-tration of sulindac which increased the half-life of MDA7protein in the cells This resulted in the increased expressionofMDA7protein and of its proapoptotic downstream effectorproteins including p38MAPK caspase-9 and caspase-3 con-sequently sensitizing the lung cancer cells to apoptosisThere-fore sulindac essentially altered MDA7 protein turnover inlung cancer cells in such a way as to promote apoptotic celldeath [50]

4 Concluding Remarks

Ongoing investigations of proapoptotic mechanisms under-lying the promising anti-neoplastic properties of NSAIDssuch as aspirin remain a top research priority since animproved understanding of such pathways will help toenhance current anticancer drug treatments [2] What is cer-tain thus far is that NSAIDs generally exert a dose-dependentpleiotropic effect on cancer cells (see Figure 2) initiatinga very complex cascade of signalling events which collec-tively induce apoptosis Although much more remains to beelucidated there is also mounting evidence which suggeststhat NSAID-induced signalling events associated with theinduction of oxidative stress such as mitochondrial dys-function and altered redox signalling may be the dominantpathways underlying all other proapoptotic effects induced byNSAIDs in cancer cells [184]

Consistent with the growing number of mammalian cellstudies implicating oxidative stress as the dominant pathwayof NSAID-induced growth inhibition [185] the proapoptoticeffects of NSAIDs in yeast cells are likewise associatedmainlywith mitochondrial dysfunction ROS generation and redoximbalance In particular yeast cell studies have highlightedthe pivotal importance of mitochondrial MnSOD as a cyto-protective defence against NSAIDs such as aspirin [32] Thisimplies that specific targeted modulation of mitochondrialMnSOD can be exploited to enhance NSAID-induced oxida-tive stress and apoptosis in malignant mammalian cells

It is currently hypothesised that cancer cells constantlyexperiencemuch higher levels of oxidative stress with respectto normal cells due to their increased metabolic rate [186]Because of this cancer cells are more reliant on antioxidantenzymes such as MnSOD and are thus believed to be farmore sensitive to perturbations in redox balance compared tonormal cells [16] In fact it has been shown that silencing ofMnSOD using anti-senseMnSOD antibodies amplifies ROS


accumulation ofarachidonic acid andceramide synthesis

Oxidative stress anddisruption of

redox balance

Caspase activationand Bcl-2 protein

modulationAspirinSulindacIndomethacin

SulindacIndomethacin

MAP kinasemodulation

AspirinIndomethacinNO-aspirinNO-sulindac Apoptotic

cell death

AspirinSulindacIndomethacinDiclofenacNO-aspirinPhosphoaspirinHS-aspirin Inhibition of

signallingAspirinSulindacIndomethacinDiclofenacNO-aspirinPhosphosulindac

Modulation of

AspirinSulindacIbuprofenIndomethacinEtoricoxibDiclofenacNO-aspirinPhosphoaspirinHS-aspirin

Depletion of survivin

Depletion of polyaminesAspirinSulindacIndomethacinIbuprofenPhosphosulindac

Inhibition ofproteasomal

functionAspirinTolfenamic acid

Increased expression of Aspirin

Sulindac

COX-2-dependent

NO-aspirinPhosphosulindac

NF-120581B signalling

Wnt120573-catenin

mda7IL24

Figure 2Themajor proapoptotic pathways induced byNSAIDs Both traditional andmodifiedNSAIDs have been shown to induce apoptosisin eukaryotic cells by initiating mechanisms which are largely independent of COX inhibition (shown in blue) with the exception being theCOX-2-dependent accumulation of arachidonic acid and subsequent synthesis of ceramide induced by sulindac and indomethacin (shown ingreen) ImportantCOX-independent proapoptotic pathways induced byNSAIDs include caspase activation andmodulation of Bcl-2 proteinsdepletion of polyamines modulation of NF-120581B signalling and of MAP kinase activity inhibition of Wnt120573-catenin signalling inhibitionof proteasomal function depletion of survivin increased expression of mda7IL24 and also oxidative stress associated with mitochondrialdysfunction ROS accumulation and the disruption of cellular redox balance

accumulation and apoptosis in squamous cell carcinomasexposed to gamma radiation and anticancer drugs [187]Moreover it has recently been shown that silencing ofMnSOD messenger RNA using small interfering RNA(siRNA) amplified apoptosis of melanoma cells induced bythe NSAID diclofenac [16] This same study also demon-strated that diclofenac-induced accumulation of ROS deple-tion of MnSOD expression and activity and apoptosis werespecific to melanoma cells

In light of all these lines of evidence compiled throughcomplementary study of both mammalian and yeast cellmodels the induction of oxidative stress and redox imbalanceinduced by NSAIDs together with the targeted modulationof mitochondrial MnSOD merits serious consideration forfuture investigations

Acknowledgments

Work in the authorsrsquo laboratory is partly funded by the MaltaGovernment Scholarship Scheme (MGSS) Award fund noME367078 toGianluca Farrugia and partly by theResearchFund grants to Rena Balzan from the University of Malta

References

[1] J A Baron and R S Sandler ldquoNonsteroidal anti-inflammatorydrugs and cancer preventionrdquo Annual Review of Medicine vol51 pp 511ndash523 2000

[2] A T Chan N Arber J Burn et al ldquoAspirin in the chemopre-vention of colorectal neoplasia an overviewrdquoCancer PreventionResearch vol 5 no 2 pp 164ndash178 2012


[3] P M Rothwell M Wilson C-E Elwin et al ldquoLong-term effectof aspirin on colorectal cancer incidence andmortality 20-yearfollow-up of five randomised trialsrdquo The Lancet vol 376 no9754 pp 1741ndash1750 2010

[4] P M Rothwell F G R Fowkes J F Belch H Ogawa C PWarlow and T W Meade ldquoEffect of daily aspirin on long-termrisk of death due to cancer analysis of individual patient datafrom randomised trialsrdquo The Lancet vol 377 no 9759 pp 31ndash41 2011

[5] MA TrujilloH SGarewal andR E Sampliner ldquoNonsteroidalantiinflammatory agents in chemoprevention of colorectal can-cer at what costrdquo Digestive Diseases and Sciences vol 39 no10 pp 2260ndash2266 1994

[6] S J Shiff L Qiao L-L Tsai and B Rigas ldquoSulindac sulfide anaspirin-like compound inhibits proliferation causes cell cyclequiescence and induces apoptosis in HT-29 colon adenocarci-noma cellsrdquo Journal of Clinical Investigation vol 96 no 1 pp491ndash503 1995

[7] T A Chan P J Morin B Vogelstein and K W KinzlerldquoMechanisms underlying nonsteroidal antiinflammatory drug-mediated apoptosisrdquoProceedings of theNational Academy of Sci-ences of the United States of America vol 95 no 2 pp 681ndash6861998

[8] M A Rahman D K Dhar R Masunaga A Yamanoi HKohno and N Nagasue ldquoSulindac and exisulind exhibit a sig-nificant antiproliferative effect and induce apoptosis in humanhepatocellular carcinoma cell linesrdquo Cancer Research vol 60no 8 pp 2085ndash2089 2000

[9] M Pollard and P H Luckert ldquoProlonged antitumor effect ofindomethacin on autochthonous intestinal tumors in ratsrdquo Jour-nal of the National Cancer Institute vol 70 no 6 pp 1103ndash11051983

[10] C H Chiu M F McEntee and J Whelan ldquoDiscordant effectof aspirin and indomethacin on intestinal tumor burden inApc(Min+) micerdquo Prostaglandins Leukotrienes and EssentialFatty Acids vol 62 no 5 pp 269ndash275 2000

[11] J Andrews D Djakiew S Krygier and P Andrews ldquoSuperioreffectiveness of ibuprofen compared with other NSAIDs forreducing the survival of human prostate cancer cellsrdquo CancerChemotherapy and Pharmacology vol 50 no 4 pp 277ndash2842002

[12] Y-S Zhao S Zhu X-W Li et al ldquoAssociation betweenNSAIDsuse and breast cancer risk a systematic review and meta-anal-ysisrdquo Breast Cancer Research and Treatment vol 117 no 1 pp141ndash150 2009

[13] T MMotawi Y Bustanji S El-Maraghy M O Taha andM AAl-Ghussein ldquoEvaluation of naproxen and cromolyn activitiesagainst cancer cells viability proliferation apoptosis p53 andgene expression of survivin and caspase-3rdquo Journal of EnzymeInhibition and Medicinal Chemistry 2013

[14] J I Johnsen M Lindskog F Ponthan et al ldquoCyclooxygenase-2 is expressed in neuroblastoma and nonsteroidal anti-inflam-matory drugs induce apoptosis and inhibit tumor growth invivordquo Cancer Research vol 64 no 20 pp 7210ndash7215 2004

[15] F CecereA Iuliano FAlbano et al ldquoDiclofenac-induced apop-tosis in the neuroblastoma cell line SH-SY5Y possible involve-ment of the mitochondrial superoxide dismutaserdquo Journal ofBiomedicine and Biotechnology vol 2010 Article ID 801726 11pages 2010

[16] F Albano A Arcucci G Granato et al ldquoMarkers of mitochon-drial dysfunction during the diclofenac-induced apoptosis inmelanoma cell linesrdquo Biochimie vol 95 pp 934ndash945 2013

[17] J LWilliams S Borgo I Hasan E Castillo F Traganos and BRigas ldquoNitric oxide-releasing nonsteroidal anti-inflammatorydrugs (NSAIDs) alter the kinetics of human colon cancer celllines more effectively than traditional NSAIDs implications forcolon cancer chemopreventionrdquo Cancer Research vol 61 no 8pp 3285ndash3289 2001

[18] K Kashfi Y Ryann L L Qiao et al ldquoNitric oxide-donatingnonsteroidal anti-inflammatory drugs inhibit the growth ofvarious cultured human cancer cells evidence of a tissue type-independent effectrdquo Journal of Pharmacology and ExperimentalTherapeutics vol 303 no 3 pp 1273ndash1282 2002

[19] W Zhao G GMackenzie O TMurray Z Zhang and B RigasldquoPhosphoaspirin (MDC-43) a novel benzyl ester of aspirininhibits the growth of human cancer cell lines more potentlythan aspirin a redox-dependent effectrdquo Carcinogenesis vol 30no 3 pp 512ndash519 2009

[20] L Huang C Zhu Y Sun et al ldquoPhospho-sulindac (OXT-922)inhibits the growth of human colon cancer cell lines a redoxpolyamine-dependent effectrdquo Carcinogenesis vol 31 no 11 pp1982ndash1990 2010

[21] L Huang G G Mackenzie Y Sun et al ldquoChemotherapeuticproperties of phospho-nonsteroidal anti-inflammatory drugs anew class of anticancer compoundsrdquo Cancer Research vol 71no 24 pp 7617ndash7627 2011

[22] M Chattopadhyay R Kodela N Nath et al ldquoHydrogen sulfide-releasing NSAIDs inhibit the growth of human cancer cellsa general property and evidence of a tissue type-independenteffectrdquo Biochemical Pharmacology vol 83 no 6 pp 715ndash7222012

[23] R Kodela M Chattopadhyay and K Kashfi ldquoNOSH-aspirina novel nitric oxide-hydrogen sulfide-releasing hybrid a newclass of anti-inflammatory pharmaceuticalsrdquo ACS MedicinalChemistry Letters vol 3 no 3 pp 257ndash262 2012

[24] M Chattopadhyay R Kodela K R Olson and K KashfildquoNOSH-aspirin (NBS-1120) a novel nitric oxide- and hydrogensulfide-releasing hybrid is a potent inhibitor of colon cancer cellgrowth in vitro and in a xenograft mouse modelrdquo Biochemicaland Biophysical Research Communications vol 419 no 3 pp523ndash528 2012

[25] L M Coussens and Z Werb ldquoInflammation and cancerrdquo Na-ture vol 420 no 6917 pp 860ndash867 2002

[26] B S Reddy C V Rao A Rivenson and G Kelloff ldquoInhibitoryeffect of aspirin on azoxymethane-induced colon carcinogen-esis in F344 ratsrdquo Carcinogenesis vol 14 no 8 pp 1493ndash14971993

[27] L Qiao R Hanif E Sphicas S J Shiff and B Rigas ldquoEffect ofaspirin on induction of apoptosis inHT-29 human colon adeno-carcinoma cellsrdquo Biochemical Pharmacology vol 55 no 1 pp53ndash64 1998

[28] H-G Yu J-A Huang Y-N Yang et al ldquoThe effects ofacetylsalicylic acid on proliferation apoptosis and invasion ofcyclooxygenase-2 negative colon cancer cellsrdquoEuropean Journalof Clinical Investigation vol 32 no 11 pp 838ndash846 2002

[29] J Gao K NiwaW Sun et al ldquoNon-steroidal anti-inflammatorydrugs inhibit cellular proliferation and upregulate cyclooxy-genase-2 protein expression in endometrial cancer cellsrdquoCancerScience vol 95 no 11 pp 901ndash907 2004

[30] D Carmona-Gutierrez T Eisenberg S Buttner C MeisingerG Kroemer and F Madeo ldquoApoptosis in yeast triggers path-ways subroutinesrdquo Cell Death and Differentiation vol 17 no 5pp 763ndash773 2010


[31] B Almeida A Silva A Mesquita B Sampaio-Marques FRodrigues and P Ludovico ldquoDrug-induced apoptosis in yeastrdquoBiochimica et Biophysica Acta vol 1783 no 7 pp 1436ndash14482008

[32] R Balzan K Sapienza D R Galea N Vassallo H Frey andW H Bannister ldquoAspirin commits yeast cells to apoptosisdepending on carbon sourcerdquo Microbiology vol 150 no 1 pp109ndash115 2004

[33] J S Van Leeuwen R Orij M A H Luttik G J Smits N P EVermeulen and J C Vos ldquoSubunits Rip1p andCox9p of the res-piratory chain contribute to diclofenac-induced mitochondrialdysfunctionrdquoMicrobiology vol 157 no 3 pp 685ndash694 2011

[34] E Castano M Dalmau M Barragan G Pueyo R Bartronsand J Gil ldquoAspirin induces cell death and caspase-dependentphosphatidylserine externalization in HT-29 human colon ade-nocarcinoma cellsrdquo British Journal of Cancer vol 81 no 2 pp294ndash299 1999

[35] L Turchanowa N Dauletbaev V Milovic and J Stein ldquoNon-steroidal anti-inflammatory drugs stimulate spermidinesper-mine acetyltransferase and deplete polyamine content in coloncancer cellsrdquo European Journal of Clinical Investigation vol 31no 10 pp 887ndash893 2001

[36] L A Stark F VDin RM Zwacka andMGDunlop ldquoAspirin-induced activation of theNF-kappaB signaling pathway a novelmechanism for aspirin-mediated apoptosis in colon cancercellsrdquoThe FASEB Journal vol 15 no 7 pp 1273ndash1275 2001

[37] B BellosilloM PiqueM Barragan et al ldquoAspirin and salicylateinduce apoptosis and activation of caspases in B-cell chroniclymphocytic leukemia cellsrdquo Blood vol 92 no 4 pp 1406ndash14141998

[38] M Pique M Barragan M Dalmau B Bellosillo G Ponsand J Gil ldquoAspirin induces apoptosis through mitochondrialcytochrome c releaserdquo FEBS Letters vol 480 no 2-3 pp 193ndash196 2000

[39] K C Zimmermann N J Waterhouse J C Goldstein MSchuler and D R Green ldquoAspirin induces apoptosis throughrelease of cytochrome c from mitochondriardquo Neoplasia vol 2no 6 pp 505ndash513 2000

[40] R Im and Y J Jang ldquoAspirin enhances TRAIL-induced apopto-sis via regulation of ERK12 activation in human cervical cancercellsrdquo Biochemical and Biophysical Research Communicationsvol 424 pp 65ndash70 2012

[41] J J PowerM S DennisM J Redlak and T AMiller ldquoAspirin-induced mucosal cell death in human gastric cells evidencesupporting an apoptotic mechanismrdquo Digestive Diseases andSciences vol 49 no 9 pp 1518ndash1525 2004

[42] Q Gu J DeWang HH X Xia et al ldquoActivation of the caspase-8Bid and Bax pathways in aspirin-induced apoptosis in gastriccancerrdquo Carcinogenesis vol 26 no 3 pp 541ndash546 2005

[43] M J Redlak J J Power and T A Miller ldquoRole of mitochondriain aspirin-induced apoptosis in human gastric epithelial cellsrdquoAmerican Journal of Physiology vol 289 no 4 pp G731ndashG7382005

[44] X M Zhou B C Y Wong X M Fan et al ldquoNon-steroidalanti-inflammatory drugs induce apoptosis in gastric cancer cellsthrough up-regulation of bax and bakrdquo Carcinogenesis vol 22no 9 pp 1393ndash1397 2001

[45] H Raza A John and S Benedict ldquoAcetylsalicylic acid-inducedoxidative stress cell cycle arrest apoptosis and mitochondrialdysfunction in human hepatoma HepG2 cellsrdquo European Jour-nal of Pharmacology vol 668 no 1-2 pp 15ndash24 2011

[46] M A Hossain D H Kim J Y Jang et al ldquoAspirin inducesapoptosis in vitro and inhibits tumor growth of human hepa-tocellular carcinoma cells in a nude mouse xenograft modelrdquoInternational Journal of Oncology vol 40 no 4 pp 1298ndash13042012

[47] P Dikshit M Chatterjee A Goswami A Mishra and NR Jana ldquoAspirin induces apoptosis through the inhibition ofproteasome functionrdquo Journal of Biological Chemistry vol 281no 39 pp 29228ndash29235 2006

[48] Y Huang Q He M J Hillman R Rong and M S SheikhldquoSulindac sulfide-induced apoptosis involves death receptor 5and the caspase 8-dependent pathway in human colon andprostate cancer cellsrdquo Cancer Research vol 61 no 18 pp 6918ndash6924 2001

[49] N Babbar N A Ignatenko R A Casero Jr and E WGerner ldquoCyclooxygenase-independent induction of apoptosisby sulindac sulfone is mediated by polyamines in colon cancerrdquoJournal of Biological Chemistry vol 278 no 48 pp 47762ndash47775 2003

[50] Y Oida B Gopalan R Miyahara et al ldquoSulindac enhancesadenoviral vector expressing mda-7IL-24-mediated apoptosisin human lung cancerrdquo Molecular Cancer Therapeutics vol 4no 2 pp 291ndash304 2005

[51] E J Greenspan J P Madigan L A Boardman and D WRosenberg ldquoIbuprofen inhibits activation of nuclear 120573-cateninin human colon adenomas and induces the phosphorylation ofGSK-3120573rdquo Cancer Prevention Research vol 4 no 1 pp 161ndash1712011

[52] U T Sankpal M Abdelrahim S F Connelly et al ldquoSmallmolecule tolfenamic acid inhibits PC-3 cell proliferation andinvasion in vitro and tumor growth in orthotopicmousemodelfor prostate cancerrdquo Prostate vol 72 pp 1648ndash1658 2012

[53] H Zhou L Huang Y Sun and B Rigas ldquoNitric oxide-donatingaspirin inhibits the growth of pancreatic cancer cells throughredox-dependent signalingrdquo Cancer Letters vol 273 no 2 pp292ndash299 2009

[54] J L Williams N Nath J Chen et al ldquoGrowth inhibitionof human colon cancer cells by nitric oxide (NO)-donatingaspirin is associated with cyclooxygenase-2 induction and beta-cateninT-cell factor signaling nuclear factor-kappaB and NOsynthase 2 inhibition Implications for chemopreventionrdquo Can-cer Research vol 63 no 22 pp 7613ndash7618 2003

[55] J I Williams P Ji N Ouyang X Liu and B Rigas ldquoNO-donating aspirin inhibits the activation of NF-120581B in humancancer cell lines and Min micerdquo Carcinogenesis vol 29 no 2pp 390ndash397 2008

[56] Y Sun and B Rigas ldquoThe thioredoxin system mediates redox-induced cell death in human colon cancer cells implications forthemechanism of action of anticancer agentsrdquoCancer Researchvol 68 no 20 pp 8269ndash8277 2008

[57] M Chattopadhyay S Goswami D B Rodes et al ldquoNO-releasing NSAIDs suppress NF-120581B signaling in vitro and in vivothrough S-nitrosylationrdquoCancer Letters vol 298 no 2 pp 204ndash211 2010

[58] J Gao X Liu and B Rigas ldquoNitric oxide-donating aspirininduces apoptosis in human colon cancer cells through induc-tion of oxidative stressrdquo Proceedings of the National Academyof Sciences of the United States of America vol 102 no 47 pp17207ndash17212 2005

[59] C Chaudhary T Singh P Kapur et al ldquoNitric oxide-releasingsulindac is a novel skin cancer chemopreventive agent for


UVB-induced photocarcinogenesisrdquo Toxicology and AppliedPharmacology vol 268 pp 249ndash255 2013

[60] M Chattopadhyay R Kodela N Nath A Barsegian D Boringand K Kashfi ldquoHydrogen sulfide-releasing aspirin suppressesNF-120581B signaling in estrogen receptor negative breast cancercells in vitro and in vivordquoBiochemical Pharmacology vol 83 no6 pp 723ndash732 2012

[61] J R Vane ldquoInhibition of prostaglandin synthesis as a mecha-nism of action for aspirin-like drugsrdquo Nature New biology vol231 no 25 pp 232ndash235 1971

[62] J R Vane J A Mitchell I Appleton et al ldquoInducible isoformsof cyclooxygenase and nitric-oxide synthase in inflammationrdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 91 no 6 pp 2046ndash2050 1994

[63] K Uefuji T Ichikura and H Mochizuki ldquoCyclooxygenase-2expression is related to prostaglandin biosynthesis and angio-genesis in human gastric cancerrdquo Clinical Cancer Research vol6 no 1 pp 135ndash138 2000

[64] L Zhang Y-D Wu P Li et al ldquoEffects of cyclooxygenase-2 onhuman esophageal squamous cell carcinomardquoWorld Journal ofGastroenterology vol 17 no 41 pp 4572ndash4580 2011

[65] C E Eberhart R J Coffey A Radhika F M Giardiello SFerrenbach and R N Dubois ldquoUp-regulation of cyclooxy-genase 2 gene expression in human colorectal adenomas andadenocarcinomasrdquo Gastroenterology vol 107 no 4 pp 1183ndash1188 1994

[66] H Sano Y Kawahito R LWilder et al ldquoExpression of cycloox-ygenase-1 and -2 in human colorectal cancerrdquo Cancer Researchvol 55 no 17 pp 3785ndash3789 1995

[67] W Kutchera D A Jones N Matsunami et al ldquoProstaglandinH synthase 2 is expressed abnormally in human colon cancerevidence for a transcriptional effectrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 93 no10 pp 4816ndash4820 1996

[68] A Lupulescu ldquoProstaglandins their inhibitors and cancerrdquoProstaglandins Leukotrienes and Essential Fatty Acids vol 54no 2 pp 83ndash94 1996

[69] G N Levy ldquoProstaglandin H synthases nonsteroidal anti-inflammatory drugs and colon cancerrdquo FASEB Journal vol 11no 4 pp 234ndash247 1997

[70] S J Shiff and B Rigas ldquoNonsteroidal anti-inflammatory drugsand colorectal cancer evolving concepts of their chemopreven-tive actionsrdquo Gastroenterology vol 113 no 6 pp 1992ndash19981997

[71] D Wang and R N Dubois ldquoProstaglandins and cancerrdquo Gutvol 55 no 1 pp 115ndash122 2006

[72] M Oshima J E Dinchuk S L Kargman et al ldquoSuppression ofintestinal polyposis in Apc(Δ716) knockout mice by inhibitionof cyclooxygenase 2 (COX-2)rdquo Cell vol 87 no 5 pp 803ndash8091996

[73] P C Chulada M B Thompson J F Mahler et al ldquoGeneticdisruption of Ptgs-1 as well as of Ptgs-2 reduces intestinaltumorigenesis inMinmicerdquo Cancer Research vol 60 no 17 pp4705ndash4708 2000

[74] B S Reddy C V Rao and K Seibert ldquoEvaluation of cyclooxy-genase-2 inhibitor for potential chemopreventive propertiesin colon carcinogenesisrdquo Cancer Research vol 56 no 20 pp4566ndash4569 1996

[75] N Arber C J Eagle J Spicak et al ldquoCelecoxib for theprevention of colorectal adenomatous polypsrdquo New EnglandJournal of Medicine vol 355 no 9 pp 885ndash895 2006

[76] J A Baron R S Sandler R S Bresalier et al ldquoA randomizedtrial of rofecoxib for the chemoprevention of colorectal adeno-masrdquo Gastroenterology vol 131 no 6 pp 1674ndash1682 2006

[77] Y Dai and W-H Wang ldquoNon-steroidal anti-inflammatorydrugs in prevention gastric cancerrdquoWorld Journal of Gastroen-terology vol 12 no 19 pp 2884ndash2889 2006

[78] N R Jana ldquoNSAIDs and apoptosisrdquo Cellular andMolecular LifeSciences vol 65 no 9 pp 1295ndash1301 2008

[79] K Sapienza and R Balzan ldquoAspirin and apoptosisrdquo in NewResearch on Aspirin and Health C L Millwood Ed Nova Sci-ence Publishers New York NY USA 2007

[80] C-H Chiu M F McEntee and J Whelan ldquoSulindac causesrapid regression of preexisting tumors in Min+ mice indepen-dent of prostaglandin biosynthesisrdquoCancer Research vol 57 no19 pp 4267ndash4273 1997

[81] R Hanif A Pittas Y Feng et al ldquoEffects of nonsteroidalanti-inflammatory drugs on proliferation and on induction ofapoptosis in colon cancer cells by a prostaglandin-independentpathwayrdquo Biochemical Pharmacology vol 52 no 2 pp 237ndash2451996

[82] Y A Hannun ldquoFunctions of ceramide in coordinating cellularresponses to stressrdquo Science vol 274 no 5294 pp 1855ndash18591996

[83] Y Cao A T Pearman G A Zimmerman T M McIntyreand S M Prescott ldquoIntracellular unesterified arachidonic acidsignals apoptosisrdquo Proceedings of the National Academy of Sci-ences of the United States of America vol 97 no 21 pp 11280ndash11285 2000

[84] L Scorrano D Penzo V Petronilli F Pagano and P BernardildquoArachidonic acid causes cell death through the mitochondrialpermeability transition Implications for tumor necrosis factor-120572 apoptotic signalingrdquo Journal of Biological Chemistry vol 276no 15 pp 12035ndash12040 2001

[85] X Zhang S G Morham R Langenbach and D A YoungldquoMalignant transformation and antineoplastic actions of nons-teroidal antiinflammatory drugs (NSAIDs) on cyclooxygenase-null embryo fibroblastsrdquo Journal of Experimental Medicine vol190 no 4 pp 451ndash459 1999

[86] D J E Elder D E Halton A Hague and C Paraskeva ldquoInduc-tion of apoptotic cell death in human colorectal carcinomacell lines by a cyclooxygenase-2 (COX-2)-selective nonsteroidalanti-inflammatory drug independence from COX-2 proteinexpressionrdquo Clinical Cancer Research vol 3 no 10 pp 1679ndash1683 1997

[87] H J Thompson S Briggs N S Paranka et al ldquoInhibitionof mammary carcinogenesis in rats by sulfone metabolite ofsulindacrdquo Journal of the National Cancer Institute vol 87 no 16pp 1259ndash1260 1995

[88] G A Piazza A L K Rahm M Krutzsch et al ldquoAntineoplasticdrugs sulindac sulfide and sulfone inhibit cell growth by induc-ing apoptosisrdquo Cancer Research vol 55 no 14 pp 3110ndash31161995

[89] D Charalambous and P E OrsquoBrien ldquoInhibition of colon cancerprecursors in the rat by sulindac sulphone is not dependent oninhibition of prostaglandin synthesisrdquo Journal of Gastroenterol-ogy and Hepatology vol 11 no 4 pp 307ndash310 1996

[90] G A Piazza D S Alberts L J Hixson et al ldquoSulindac sulfoneinhibits azoxymethane-induced colon carcinogenesis in ratswithout reducing prostaglandin levelsrdquoCancer Research vol 57no 14 pp 2909ndash2915 1997

[91] R Yamazaki N Kusunoki T Matsuzaki S Hashimoto andS Kawai ldquoAspirin and sodium salicylate inhibit proliferation


and induce apoptosis in rheumatoid synovial cellsrdquo Journal ofPharmacy and Pharmacology vol 54 no 12 pp 1675ndash16792002

[92] B B Wolf and D R Green ldquoSuicidal tendencies apoptotic celldeath by caspase family proteinasesrdquo Journal of Biological Chem-istry vol 274 no 29 pp 20049ndash20052 1999

[93] K Sapienza W Bannister and R Balzan ldquoMitochondrialinvolvement in aspirin-induced apoptosis in yeastrdquo Microbiol-ogy vol 154 no 9 pp 2740ndash2747 2008

[94] H Li H Zhu C-J Xu and J Yuan ldquoCleavage of BID by caspase8 mediates the mitochondrial damage in the Fas pathway ofapoptosisrdquo Cell vol 94 no 4 pp 491ndash501 1998

[95] M Kruidering and G I Evan ldquoCaspase-8 in apoptosis thebeginning of ldquothe endrdquordquo IUBMB Life vol 50 no 2 pp 85ndash902000

[96] X Roucou S Montessuit B Antonsson and J-C MartinouldquoBax oligomerization in mitochondrial membranes requirestBid (caspase-8-cleaved Bid) and a mitochondrial proteinrdquo Bio-chemical Journal vol 368 no 3 pp 915ndash921 2002

[97] N Nath G Labaze B Rigas and K Kashfi ldquoNO-donatingaspirin inhibits the growth of leukemic Jurkat cells and mod-ulates 120573-catenin expressionrdquo Biochemical and Biophysical Re-search Communications vol 326 no 1 pp 93ndash99 2005

[98] A Bank J Yu and L Zhang ldquoNSAIDs downregulate Bcl-XLand dissociate BAX and Bcl-X L to induce apoptosis in coloncancer cellsrdquo Nutrition and Cancer vol 60 no 1 pp 98ndash1032008

[99] I Petrescu and C Tarba ldquoUncoupling effects of diclofenac andaspirin in the perfused liver and isolated hepatic mitochondriaof ratrdquo Biochimica et Biophysica Acta-Bioenergetics vol 1318 no3 pp 385ndash394 1997

[100] S A Uyemura A C Santos F E Mingatto M C Jordaniand C Curti ldquoDiclofenac sodium and mefenamic acid potentinducers of the membrane permeability transition in renal cor-tex mitochondriardquo Archives of Biochemistry and Biophysics vol342 no 2 pp 231ndash235 1997

[101] K-W Oh T Qian D A Brenner and J J Lemasters ldquoSalicylateenhances necrosis and apoptosismediated by themitochondrialpermeability transitionrdquo Toxicological Sciences vol 73 no 1 pp44ndash52 2003

[102] A E Pegg ldquoPolyamine metabolism and its importance inneoplastic growth and as a target for chemotherapyrdquo CancerResearch vol 48 no 4 pp 759ndash774 1988

[103] D Russell and SH Snyder ldquoAmine synthesis in rapidly growingtissues ornithine decarboxylase activity in regenerating ratliver chick embryo and various tumorsrdquo Proceedings of theNational Academy of Sciences of theUnited States of America vol60 no 4 pp 1420ndash1427 1968

[104] F L Meyskens Jr and E W Gerner ldquoDevelopment of difluo-romethylornithine as a chemoprevention agent for themanage-ment of colon cancerrdquo Journal of Cellular Biochemistry vol 58no 22 pp 126ndash131 1995

[105] F Scorcioni A Corti P Davalli S Astancolle and S Bet-tuzzi ldquoManipulation of the expression of regulatory genes ofpolyamine metabolism results in specific alterations of the cell-cycle progressionrdquo Biochemical Journal vol 354 no 1 pp 217ndash223 2001

[106] L Li J N Rao B L Bass and J-YWang ldquoNF-120581B activation andsusceptibility to apoptosis after polyamine depletion in intesti-nal epithelial cellsrdquoAmerican Journal of Physiology vol 280 no5 pp G992ndashG1004 2001

[107] N Babbar E W Gerner and R A Casero Jr ldquoInduction ofspermidinespermine N1-acetyltransferase (SSAT) by aspirin inCaco-2 colon cancer cellsrdquo Biochemical Journal vol 394 no 1pp 317ndash324 2006

[108] M E Martınez T G OrsquoBrien K E Fultz et al ldquoPronouncedreduction in adenoma recurrence associated with aspirin useand a polymorphism in the ornithine decarboxylase generdquo Pro-ceedings of the National Academy of Sciences of the United Statesof America vol 100 no 13 pp 7859ndash7864 2003

[109] F L Meyskens Jr C E McLaren D Pelot et al ldquoDifluo-romethylornithine plus sulindac for the prevention of spo-radic colorectal adenomas a randomized placebo-controlleddouble-blind trialrdquo Cancer Prevention Research vol 1 no 1 pp32ndash38 2008

[110] G G Mackenzie N Ouyang G Xie et al ldquoPhospho-sulindac(OXT-328) combined with difluoromethylornithine preventscolon cancer in micerdquo Cancer Prevention Research vol 4 no 7pp 1052ndash1060 2011

[111] G G MacKenzie Y Sun L Huang et al ldquoPhospho-sulindac(OXT-328) a novel sulindac derivative is safe and effective incolon cancer prevention in micerdquoGastroenterology vol 139 no4 pp 1320ndash1332 2010

[112] P A Baeuerle and D Baltimore ldquoNf-120581B ten years afterrdquo Cellvol 87 no 1 pp 13ndash20 1996

[113] M Karin ldquoThe beginning of the end I120581B kinase (IKK) and NF-120581B activationrdquo Journal of Biological Chemistry vol 274 no 39pp 27339ndash27342 1999

[114] M-J Yin Y Yamamoto and R B Gaynor ldquoThe anti-inflam-matory agents aspirin and salicylate inhibit the activity of I120581Bkinase-120573rdquo Nature vol 396 no 6706 pp 77ndash80 1998

[115] H Algul G Adler and R M Schmid ldquoNF-kappaBRel tran-scriptional pathway implications in pancreatic cancerrdquo Inter-national Journal of Gastrointestinal Cancer vol 31 pp 71ndash782002

[116] K M Ahmed N Cao and J J Li ldquoHER-2 and NF-120581B as thetargets for therapy-resistant breast cancerrdquoAnticancer Researchvol 26 no 6 B pp 4235ndash4243 2006

[117] S Setia and S N Sanyal ldquoDownregulation of NF-kappaB andPCNA in the regulatory pathways of apoptosis by cyclooxy-genase-2 inhibitors in experimental lung cancerrdquoMolecular andCellular Biochemistry vol 369 pp 75ndash86 2012

[118] D J A de Groot E G E de Vries H J M Groen and Sde Jong ldquoNon-steroidal anti-inflammatory drugs to potentiatechemotherapy effects from lab to clinicrdquo Critical Reviews inOncologyHematology vol 61 no 1 pp 52ndash69 2007

[119] E Kopp and S Ghosh ldquoInhibition of NF-120581B by sodium sali-cylate and aspirinrdquo Science vol 265 no 5174 pp 956ndash959 1994

[120] J W Pierce M A Read H Ding F W Luscinskas andT Collins ldquoSalicylates inhibit I120581B-120572 phosphorylation endo-thelial-leukocyte adhesionmolecule expression and neutrophiltransmigrationrdquo Journal of Immunology vol 156 no 10 pp3961ndash3969 1996

[121] P Schwenger D Alpert E Y Skolnik and J Vilcek ldquoActivationof p38 mitogen-activated protein kinase by sodium salicylateleads to inhibition of tumor necrosis factor-induced I120581B120572 phos-phorylation and degradationrdquo Molecular and Cellular Biologyvol 18 no 1 pp 78ndash84 1998

[122] Y Yamamoto M-J Yin K-M Lin and R B Gaynor ldquoSulindacinhibits activation of the NF-120581B pathwayrdquo Journal of BiologicalChemistry vol 274 no 38 pp 27307ndash27314 1999


[123] J R Matthews N Wakasugi J-L Virelizier J Yodoi and R THay ldquoThioredoxin regulates theDNAbinding activity ofNF-120581Bby reduction of a disulphide bond involving cysteine 62rdquoNucleicAcids Research vol 20 no 15 pp 3821ndash3830 1992

[124] F V N Din M G Dunlop and L A Stark ldquoEvidence forcolorectal cancer cell specificity of aspirin effects on NF120581Bsignalling and apoptosisrdquoBritish Journal of Cancer vol 91 no 2pp 381ndash388 2004

[125] G M Borthwick A S Johnson M Partington J Burn R Wil-son and H M Arthur ldquoTherapeutic levels of aspirin and sali-cylate directly inhibit a model of angiogenesis through a Cox-independent mechanismrdquo FASEB Journal vol 20 no 12 pp2009ndash2016 2006

[126] L A Stark K Reid O J Sansom et al ldquoAspirin activates theNF-120581B signalling pathway and induces apoptosis in intestinalneoplasia in two in vivo models of human colorectal cancerrdquoCarcinogenesis vol 28 no 5 pp 968ndash976 2007

[127] M Cho J Gwak S Park et al ldquoDiclofenac attenuates Wnt120573-catenin signaling in colon cancer cells by activation of NF-120581BrdquoFEBS Letters vol 579 no 20 pp 4213ndash4218 2005

[128] K-A Sheppard DW Rose Z K Haque et al ldquoTranscriptionalactivation by NF-120581B requires multiple coactivatorsrdquo Molecularand Cellular Biology vol 19 no 9 pp 6367ndash6378 1999

[129] M H Cobb and E J Goldsmith ldquoHow MAP kinases areregulatedrdquo Journal of Biological Chemistry vol 270 no 25 pp14843ndash14846 1995

[130] P Schwenger P Bellosta I Vietor C Basilico E Y Skolnikand J Vilcek ldquoSodium salicylate induces apoptosis via p38mitogen-activated protein kinase but inhibits tumor necrosisfactor-induced c-Jun N-terminal kinasestress-activated pro-tein kinase activationrdquo Proceedings of the National Academy ofSciences of the United States of America vol 94 no 7 pp 2869ndash2873 1997

[131] P Schwenger E Y Skolnik and J Vilcek ldquoInhibition of tumornecrosis factor-induced p42p44 mitogen-activated proteinkinase activation by sodium salicylaterdquo Journal of BiologicalChemistry vol 271 no 14 pp 8089ndash8094 1996

[132] M K Jones H Wang B M Peskar et al ldquoInhibition of angio-genesis by nonsteroidal anti-inflammatory drugs insight intomechanisms and implications for cancer growth and ulcer heal-ingrdquo Nature Medicine vol 5 no 12 pp 1418ndash1423 1999

[133] Z Xia M Dickens J Raingeaud R J Davis and M E Green-berg ldquoOpposing effects of ERK and JNK-p38 MAP kinases onapoptosisrdquo Science vol 270 no 5240 pp 1326ndash1331 1995

[134] Z Dong C Huang R E Brown and W-Y Ma ldquoInhibitionof activator protein 1 activity and neoplastic transformation byaspirinrdquo Journal of Biological Chemistry vol 272 no 15 pp9962ndash9970 1997

[135] T R Hundley and B Rigas ldquoNitric oxide-donating aspirininhibits colon cancer cell growth via mitogen-activated proteinkinase activationrdquo Journal of Pharmacology and ExperimentalTherapeutics vol 316 no 1 pp 25ndash34 2006

[136] M Benhar D Engelberg and A Levitzki ldquoROS stress-activated kinases and stress signaling in cancerrdquo EMBOReportsvol 3 no 5 pp 420ndash425 2002

[137] R T Moon B Bowerman M Boutros and N Perrimon ldquoThepromise andperils ofWnt signaling through120573-cateninrdquo Sciencevol 296 no 5573 pp 1644ndash1646 2002

[138] X P Hao T G Pretlow J S Rao and T P Pretlow ldquo120573-cateninexpression is altered in human colonic aberrant crypt focirdquoCan-cer Research vol 61 no 22 pp 8085ndash8088 2001

[139] J M Chiang Y HWu Chou T C Chen K F Ng and J L LinldquoNuclear 120573-catenin expression is closely related to ulcerativegrowth of colorectal carcinomardquo British Journal of Cancer vol86 no 7 pp 1124ndash1129 2002

[140] E J Chung S-G Hwang P Nguyen et al ldquoRegulation ofleukemic cell adhesion proliferation and survival by 120573-cate-ninrdquo Blood vol 100 no 3 pp 982ndash990 2002

[141] D Lu Y Zhao R Tawatao et al ldquoActivation of theWnt signalingpathway in chronic lymphocytic leukemiardquo Proceedings of theNational Academy of Sciences of the United States of Americavol 101 no 9 pp 3118ndash3123 2004

[142] W Lu H N Tinsley A Keeton Z Qu G A Piazza and Y LildquoSuppression of Wnt120573-catenin signaling inhibits prostate can-cer cell proliferationrdquo European Journal of Pharmacology vol602 no 1 pp 8ndash14 2009

[143] P Cowin T M Rowlands and S J Hatsell ldquoCadherins andcatenins in breast cancerrdquo Current Opinion in Cell Biology vol17 no 5 pp 499ndash508 2005

[144] M Shtutman J Zhurinsky I Simcha et al ldquoThe cyclin D1 geneis a target of the 120573-cateninLEF-1 pathwayrdquo Proceedings of theNational Academy of Sciences of theUnited States of America vol96 no 10 pp 5522ndash5527 1999

[145] N Nath K Kashfi J Chen and B Rigas ldquoNitric oxide-donatingaspirin inhibits 120573-cateninT cell factor (TCF) signaling inSW480 colon cancer cells by disrupting the nuclear 120573-catenin-TCF associationrdquo Proceedings of the National Academy of Sci-ences of the United States of America vol 100 no 22 pp 12584ndash12589 2003

[146] S Dihlmann A Siermann and M Von Knebel DoeberitzldquoThe nonsteroidal anti-inflammatory drugs aspirin and indo-methacin attenuate 120573-cateninTCF-4 signalingrdquo Oncogene vol20 no 5 pp 645ndash653 2001

[147] S Dihlmann S Klein and M V K Doeberitz Mv ldquoReductionof beta-cateninT-cell transcription factor signaling by aspirinand indomethacin is caused by an increased stabilization ofphosphorylated beta-cateninrdquo Molecular cancer therapeuticsvol 2 no 6 pp 509ndash516 2003

[148] C L Bos L L Kodach G R Van Den Brink et al ldquoEffect ofaspirin on the Wnt120573-catenin pathway is mediated via proteinphosphatase 2Ardquo Oncogene vol 25 no 49 pp 6447ndash64562006

[149] S Pathi I Jutooru G Chadalapaka V Nair S O Lee and SSafe ldquoAspirin inhibits colon cancer cell and tumor growth anddownregulates specificity protein (sp) transcription factorsrdquoPLoS ONE vol 7 Article ID e48208 2012

[150] P L Rice J Kelloff H Sullivan et al ldquoSulindac metabolitesinduce caspase- and proteasome-dependent degradation ofbeta-catenin protein in human colon cancer cellsrdquo Molecularcancer therapeutics vol 2 no 9 pp 885ndash892 2003

[151] Y Wang X Chen W Zhu H Zhang S Hu and X CongldquoGrowth inhibition of mesenchymal stem cells by aspirininvolvement of the wnt120573-catenin signal pathwayrdquo Clinical andExperimental Pharmacology and Physiology vol 33 no 8 pp696ndash701 2006

[152] H Li L Liu M L David et al ldquoPro-apoptotic actions ofexisulind and CP461 in SW480 colon tumor cells involve 120573-catenin and cyclin D1 down-regulationrdquo Biochemical Pharma-cology vol 64 no 9 pp 1325ndash1336 2002

[153] L Deng S Hu A R Baydoun J Chen X Chen and X CongldquoAspirin induces apoptosis inmesenchymal stem cells requiringWnt120573-catenin pathwayrdquo Cell Proliferation vol 42 no 6 pp721ndash730 2009


[154] C V Rao B S Reddy V E Steele et al ldquoNitric oxide-releasing aspirin and indomethacin are potent inhibitors againstcolon cancer in azoxymethane-treated rats effects onmoleculartargetsrdquo Molecular Cancer Therapeutics vol 5 no 6 pp 1530ndash1538 2006

[155] NNath R VassellMChattopadhyayMKogan andKKashfildquoNitro-aspirin inhibits MCF-7 breast cancer cell growth effectson COX-2 expression and Wnt120573-cateninTCF-4 signalingrdquoBiochemical Pharmacology vol 78 no 10 pp 1298ndash1304 2009

[156] C Zhu K W Cheng N Ouyang et al ldquoPhosphosulindac(OXT-328) selectively targets breast cancer stem cells in vitroand in human breast cancer xenograftsrdquo Stem Cells vol 30 pp2065ndash2075 2012

[157] M Adachi H Sakamoto R Kawamura W Wang K Imaiand Y Shinomura ldquoNonsteroidal anti-inflammatory drugs andoxidative stress in cancer cellsrdquo Histology and Histopathologyvol 22 no 4ndash6 pp 437ndash442 2007

[158] B Rigas ldquoNovel agents for cancer prevention based on nitricoxiderdquo Biochemical Society Transactions vol 35 no 5 pp 1364ndash1368 2007

[159] E Fernandes S A Toste J L F C Lima and S Reis ldquoThemetabolism of sulindac enhances its scavenging activity againstreactive oxygen and nitrogen speciesrdquo Free Radical Biology andMedicine vol 35 no 9 pp 1008ndash1017 2003

[160] D Costa A Gomes S Reis J L F C Lima and E FernandesldquoHydrogen peroxide scavenging activity by non-steroidal anti-inflammatory drugsrdquo Life Sciences vol 76 no 24 pp 2841ndash2848 2005

[161] A El Midaoui R Wu and J De Champlain ldquoPrevention ofhypertension hyperglycemia and vascular oxidative stress byaspirin treatment in chronically glucose-fed ratsrdquo Journal ofHypertension vol 20 no 7 pp 1407ndash1412 2002

[162] T Ishizuka A Niwa M Tabuchi K Ooshima and H Higash-ino ldquoAcetylsalicylic acid provides cerebrovascular protectionfrom oxidant damage in salt-loaded stroke-prone ratsrdquo LifeSciences vol 82 no 13-14 pp 806ndash815 2008

[163] S S Kumari A Varghese D Muraleedharan and V P MenonldquoProtective action of aspirin in experimental myocardial infarc-tion induced by isoproterenol in rats and its effect on lipidperoxidationrdquo Indian Journal of Experimental Biology vol 28no 5 pp 480ndash485 1990

[164] L-Y Qiu J Yu Y Zhou and C-H Chen ldquoProtective effectsand mechanism of action of aspirin on focal cerebral ischemia-reperfusion in ratsrdquo Yaoxue Xuebao vol 38 no 8 pp 561ndash5642003

[165] M Tauseef K K Sharma and M Fahim ldquoAspirin restoresnormal baroreflex function in hypercholesterolemic rats by itsantioxidative actionrdquo European Journal of Pharmacology vol556 no 1ndash3 pp 136ndash143 2007

[166] S S Kanwar K Vaiphei B Nehru and S N Sanyal ldquoAntioxida-tive effects of nonsteroidal anti-inflammatory drugs during theinitiation stages of experimental colon carcinogenesis in ratsrdquoJournal of Environmental Pathology Toxicology and Oncologyvol 27 no 2 pp 89ndash100 2008

[167] E C Yiannakopoulou and E Tiligada ldquoProtective effect ofsalicylates against hydrogen peroxide stress in yeastrdquo Journal ofApplied Microbiology vol 106 no 3 pp 903ndash908 2009

[168] H Kusuhara H Komatsu H Sumichika and K SugaharaldquoReactive oxygen species are involved in the apoptosis inducedby nonsteroidal anti-inflammatory drugs in cultured gastriccellsrdquoEuropean Journal of Pharmacology vol 383 no 3 pp 331ndash337 1999

[169] C Giardina and M S Inan ldquoNonsteroidal anti-inflammatorydrugs short-chain fatty acids and reactive oxygen metabolismin human colorectal cancer cellsrdquoBiochimica et Biophysica Actavol 1401 no 3 pp 277ndash288 1998

[170] Y M Chung Y S Bae and S Y Lee ldquoMolecular ordering ofROS production mitochondrial changes and caspase activa-tion during sodium salicylate-induced apoptosisrdquo Free RadicalBiology and Medicine vol 34 no 4 pp 434ndash442 2003

[171] T Minami M Adachi R Kawamura Y Zhang Y Shinomuraand K Imai ldquoSulindac enhances the proteasome inhibitorbortezomib-mediated oxidative stress and anticancer activityrdquoClinical Cancer Research vol 11 no 14 pp 5248ndash5256 2005

[172] E Herrero J Ros G Bellı and E Cabiscol ldquoRedox control andoxidative stress in yeast cellsrdquoBiochimica et Biophysica Acta vol1780 no 11 pp 1217ndash1235 2008

[173] V Battaglia M Salvi and A Toninello ldquoOxidative stress isresponsible for mitochondrial permeability transition induc-tion by salicylate in liver mitochondriardquo Journal of BiologicalChemistry vol 280 no 40 pp 33864ndash33872 2005

[174] H Raza and A John ldquoImplications of altered glutathionemetabolism in aspirin-induced oxidative stress and mitochon-drial dysfunction in HepG2 cellsrdquo PLoS ONE vol 7 no 4Article ID e36325 2012

[175] K Sapienza and R Balzan ldquoMetabolic aspects of aspirin-induced apoptosis in yeastrdquo FEMS Yeast Research vol 5 no 12pp 1207ndash1213 2005

[176] S Fukuda and L M Pelus ldquoSurvivin a cancer target with anemerging role in normal adult tissuesrdquoMolecular CancerThera-peutics vol 5 no 5 pp 1087ndash1098 2006

[177] M Lu A Strohecker F Chen et al ldquoAspirin sensitizes cancercells to TRAIL-induced apoptosis by reducing survivin levelsrdquoClinical Cancer Research vol 14 no 10 pp 3168ndash3176 2008

[178] M Wang Z Tan R Zhang S V Kotenko and P Liang ldquoInter-leukin 24 (MDA-7MOB-5) signals through two heterodimericreceptors IL-22R1IL-20R2 and IL-20R1IL-20R2rdquo Journal ofBiological Chemistry vol 277 no 9 pp 7341ndash7347 2002

[179] S Chada R B Sutton S Ekmekcioglu et al ldquoMDA-7IL-24 isa unique cytokine-tumor suppressor in the IL-10 Familyrdquo Inter-national Immunopharmacology vol 4 no 5 pp 649ndash667 2004

[180] Z-Z Su M T Madireddi J J Lin et al ldquoThe cancer growthsuppressor gene mda-7 selectively induces apoptosis in humanbreast cancer cells and inhibits tumor growth in nude micerdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 95 no 24 pp 14400ndash14405 1998

[181] H Jiang Z-Z Su J J L Jiao Jiao Lin N I Goldstein C S HYoung and P B Fisher ldquoThe melanoma differentiation associ-ated gene mda-7 suppresses cancer cell growthrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 93 no 17 pp 9160ndash9165 1996

[182] Y Saito R Miyahara B Gopalan et al ldquoSelective induction ofcell cycle arrest and apoptosis in human prostate cancer cellsthrough adenoviral transfer of the melanoma differentiation-associated-7 (mda-7)interleukin-24 (IL-24) generdquoCancerGeneTherapy vol 12 no 3 pp 238ndash247 2005

[183] T Saeki A Mhashilkar X Swanson et al ldquoInhibition of humanlung cancer growth following adenovirus-mediatedmda-7 geneexpression in vivordquo Oncogene vol 21 no 29 pp 4558ndash45662002

[184] Y Sun J Chen and B Rigas ldquoChemopreventive agents induceoxidative stress in cancer cells leading to COX-2 overexpressionand COX-2-independent cell deathrdquoCarcinogenesis vol 30 no1 pp 93ndash100 2009


[185] B Rigas and Y Sun ldquoInduction of oxidative stress as amechanismof action of chemopreventive agents against cancerrdquoBritish Journal of Cancer vol 98 no 7 pp 1157ndash1160 2008

[186] Y QinWDai YWang X G Gong andM Lu ldquoFe-SOD coop-erates withNutlin3 to selectively inhibit cancer cells in vitro andin vivordquo Biochemical and Biophysical Research Communicationsvol 431 pp 169ndash175 2013

[187] E Ueta K Yoneda T Kimura et al ldquoMn-SOD antisense upreg-ulates in vivo apoptosis of squamous cell carcinoma cells byanticancer drugs and 120574-rays regulating expression of the BcL-2family proteins COX-2 and p21rdquo International Journal of Can-cer vol 94 no 4 pp 545ndash550 2001

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


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of


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EndocrinologyInternational Journal of



Disease Markers


BioMed Research International

OncologyJournal of



Oxidative Medicine and Cellular Longevity


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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Research and TreatmentAIDS


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Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom


aliphatic spacermolecules as shown in Figure 1The resultingmodified NSAID classes known as NO-donating NSAIDs(NO-NSAIDs) H

2S-donating NSAIDs (HS-NSAIDs) and

phospho-NSAIDs respectively have all been shown to befar less toxic than their NSAID precursors and several timesmore potent in terms of antineoplastic efficacy [17ndash22]The exceedingly potent anti-neoplastic properties of novelNSAID chimeras which are characterized by their pos-session of both NO- and H

2S-donating moieties (see Figure

1) have also begun to attract significant attention [23 24]The mechanistic pathways which mediate the anti-neo-

plastic effects of traditional andmodifiedNSAIDs are still notfully understood It has been postulated that the antiprolifer-ative effect of NSAIDs on malignant cells involves the inhibi-tion of proinflammatory COX activity [25] and prostaglandinformation [26] However additional evidence shows thatNSAIDs can induce apoptotic cell death in tumour cells [27]via pathways that are largely independent of COX [6 2829]The elucidation of apoptotic mechanisms underlying thechemopreventive effect of NSAIDs has long been the focus ofintense research using a broad range of experimental modelsincluding whole mammalian specimens human cancer celllines and Saccharomyces cerevisiae cells

11 Yeast Cells as a Model for the Study of the ProapoptoticEffects of NSAIDs Yeast cell species such as Saccharomycescerevisiae are among the preferred and extensively usedexperimental models for the study of programmed celldeath associated with ageing disease and cancers in livingorganisms This is partly because yeast cells retain many coreelements of mammalian cell processes such as apoptosis [30]Additionally these primitive eukaryotes have a number ofimportant advantages over complex mammalian cell modelsYeast cells are relatively inexpensive and easy to handle witha relatively brief lifespan that permits rapid generation ofexperimental results in a shorter span of time Moreover theyeast cell genome is verywell characterised and relatively easyto manipulate allowing for the ready availability of yeastmutant strains for experimental studies Overall these fea-tures collectively account for the successful use of buddingyeast as a model organism for the study of molecular path-ways underlying mammalian pathologies such as cancer

These same advantages of the yeast cell experimentalmodel also account for its wide use in the study of proapop-totic pathways underlying the anti-neoplastic behaviour ofantitumour drugs such as paclitaxel bleomycin valproateand arsenic [31] These compounds have been studied exten-sively in yeast cells in an effort to improve anticancerstrategies in human patients Likewise S cerevisiae buddingyeast cells have also been used to study the growth inhibitoryproapoptotic effects of NSAIDs such as aspirin [32] anddiclofenac [33]

The study of the proapoptotic effects of NSAIDs in yeastmodels is still a relatively new concept with far fewer studieshaving been carried out in yeast with respect to mammaliancells Regardless evidence acquired thus far from yeaststudies of NSAIDs such as aspirin has already yielded valu-able insights into their proapoptotic behaviour highlighting

Table 1 Human cancer cell targets of the proapoptotic effects ofprominent traditional and modified NSAIDs

NSAID type Target cell type [references]Traditional NSAIDs

Aspirin

Colon cancer cells [34ndash36] leukaemia cells[37 38] cervical cancer cells [39 40]gastric cancer cells [41ndash44] hepatocellularcarcinoma cells [45 46] endometrialcancer cells [29] neuroblastoma cells [47]

Indomethacin Colon cancer cells [7 35] Gastric cancercells [44] Endometrial cancer cells [29]

SulindacColon cancer cells [6 7 48 49] prostatecancer cells [48] hepatocellular carcinomacells [8] lung cancer cells [50]

Ibuprofen Colon cancer cells [51]

Diclofenac Neuroblastoma cells [15] melanoma cells[16]

Tolfenamic Acid Prostate cancer cells [52]

Modified NSAIDs

NO-Aspirin Pancreatic cancer cells [53] colon cancercells [17 54ndash58]

NO-sulindac Colon cancer cells [17] melanoma cells[59]

NO-ibuprofen Colon cancer cells [17]NOSH-aspirin Colon cancer cells [24]

Phosphoaspirin Colon [19 21 56] pancreatic [21] andbreast [21] cancer cells

Phosphosulindac Colon pancreatic and breast cancer cells[21]

HS-aspirin Colon cancer cells [22] breast cancer cells[60]

HS-ibuprofen Colon cancer cells [22]HS-naproxen Colon cancer cells [22]HS-sulindac Colon cancer cells [22]

factorswhich play key roles inNSAID-induced death (such asreactive oxygen species (ROS) and mitochondrial dysfunc-tion) In fact compelling evidence has shown that S cerevisiaecells constitute a powerful model for the screening and devel-opment of NSAIDs and other proapoptotic drugs designedfor use in human cancer patients overcoming the problem ofcell specificity in the design of antitumour compounds [31]whilst also serving as an inexpensivemodel to initially test theeffect of antitumour drugs before assaying them in more rel-evant mammalian systemsTherefore yeast cells clearly servean important role as a complementary experimentalmodel tomammalian cells in the study and elucidation of NSAID-induced mechanisms of apoptosis

In this review important biomolecular pathways trig-gered by traditional and novel NSAIDs which lead to theinduction of apoptosis in mammalian cell lines and in S cere-visiae yeast cells will be discussed The significance of theseproapoptotic mechanisms in the context of the role NSAIDsmay play in the design of more effective cancer preventionstrategies is also considered




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Review Article The Proapoptotic Effect of Traditional and ...downloads.hindawi.com/journals/omcl/2013/504230.pdf · The Proapoptotic Effect of Traditional and Novel Nonsteroidal Anti-Inflammatory