藥物的致癌性課件

藥物致癌性的研究

現(xiàn)狀和動態(tài)第二軍醫(yī)大學藥物安全性評價中心第二軍醫(yī)大學衛(wèi)生毒理學教研室張?zhí)鞂毸幬镏掳┬匝芯康谋匾阅[瘤是一類嚴重影響人類健康和生命的疾病腫瘤已成為人類死亡的第1或2位原因，每年約有700萬人死于癌癥。據(jù)2003年WHO資料,目前每年新增腫瘤1000萬人，其中男性530萬人，與1990年相比，全球癌癥患者發(fā)病率增長19％，死亡率增長了18％。

我國惡性腫瘤(2000年)在各種死因中排在第二位，城市已排在首位。每年新增腫瘤200萬人。據(jù)預測我國2010年年發(fā)病數(shù)220萬，2020年為300萬。Age-adjustedCancerDeathRates,bySite,US,1930-2005Whatmaycausecancer?

Hereditarydisorders

ChemicalsVirusesChronicinflammation???WORLDHEALTHORGANIZATIONINTERNATIONALAGENCYFORRESEARCHONCANCERIARCMonographEvaluationsLYON,FRANCESlidecourtesyofV.Cogliano(IARC)IARC(2009)-monographs.iarc.frCarcinogenictohumans(group1)–108agentsProbablycarcinogenictohumans(group2A)–66Possiblycarcinogenictohumans(group2B)–248Notclassifiableastoitscarcinogenicitytohumans

(group3)–515

Probablynotcarcinogenictohumans(group4)–1IARC:IARCGroup1–Carcinogenictohumans

Medicaldrugsandtreatments 24 Industrialprocesses 13 Infectiousagentsorprocesses 10 Physicalagents 10 Industrialchemicals 7 Inhaledparticulates 5 Metalsandinorganicsalts 5 Lifestylefactors(incl.herbalremedies) 7 Other 8Group2A–66

Medicaldrugsandtreatments12

在研究藥物的潛在致癌作用中，致癌試驗比現(xiàn)有遺傳毒性試驗和系統(tǒng)暴露評價技術更有意義。致癌試驗仍是目前評價藥物致癌作用最可靠和最有意義的方法

已評價的致癌物中有93%(515/554)至少在三項標準遺傳毒性試驗中有一項呈陽性,表明在檢測致癌物（敏感性）是成功的；然而鑒定非致癌物的能力（特異性）較差，183種在大、小鼠致癌試驗中為陰性的物質(zhì)80%以上有體外遺傳毒性陽性的資料。PerformanceofindividualgenotoxictestsindetectingrodentcarcinogensasanalyzedbyKirklandetal.(2005).

AmesMLNMNSensitivity(%)58.8 73.1 78.7Specificity(%)73.939.030.8Ames+MLAAmes+MNMLA+MNAmes+MLA+MNSensitivity(%)81.085.987.090.7Specificity(%)32.4 12.010.05.0PerformanceofsimultaneoustestingbatteriesofgenotoxictestsindetectingrodentcarcinogensasanalyzedIndomethacin(吲哚美鋅)testednegativeforinvivocytogeneticassaysintheregulatorytests,butwasreportedpositivefortheinductionofDNAadductsintheliterature.Halothane(氟烷)andpyrazinamide(吡嗪酰胺)werealsoinvivopositiveforcomettestinhumanlymphocytesandinductionofspermheadabnormalitiesinmice,respectively,whichareconsiderednon-regulatorytests.某些藥物是非遺傳毒性的致癌物---用遺傳毒性試驗無法檢出很多管理機構都提出了致癌試驗的要求日本(1990)，如果臨床預期連續(xù)用藥6個月或更長時間，則需要進行致癌試驗。盡管連續(xù)用藥少于6個月，如果存在潛在致癌性因素，也可能需要進行致癌試驗。美國，一般藥物使用3個月或更長時間，需要進行致癌試驗。歐洲，規(guī)定長期應用的藥物，即至少6個月的連續(xù)用藥，或頻繁的間歇性用藥以致總的暴露量與前者相似的藥物需要進行致癌試驗.2010年04月01日我國SFDA制定發(fā)布了《藥物致癌試驗必要性的技術指導原則》藥物致癌試驗

2010年04月01日SFDA制定發(fā)布了《藥物致癌試驗必要性的技術指導原則》

預期臨床用藥期至少連續(xù)6個月的藥物一般應進行。

連續(xù)用藥沒有6個月，但以間歇的方式重復使用，如治療慢性和復發(fā)性疾病(包括過敏性鼻炎、抑郁癥和焦慮癥)，而需經(jīng)常間歇使用的藥物，一般也需進行。

某些可能導致暴露時間延長的釋藥系統(tǒng)，也應考慮進行致癌試驗。

存在潛在致癌的擔憂因素

1）已有證據(jù)顯示此類藥物具有與人類相關的潛在致癌性；

2）其構效關系提示致癌的風險；

3）重復給藥毒性試驗中有癌前病變的證據(jù)；

4）導致局部組織反應或其它病理生理變化的化合物或其代謝產(chǎn)物在組織內(nèi)長期滯留內(nèi)源性肽類、蛋白類物質(zhì)及其類似物

對于替代治療的內(nèi)源性物質(zhì)（濃度在生理水平），尤其是當同類產(chǎn)品（如動物胰島素、垂體來源的生長激素和降鈣素）已有臨床使用經(jīng)驗時，通常不需要進行致癌試驗1）其生物活性與天然物質(zhì)明顯不同；2）與天然物質(zhì)比較顯示修飾后結(jié)構發(fā)生明顯改變3）藥物的暴露量超過了血液或組織中的正常水平

化學致癌的過程及其機制化學致癌(chemicalcarcinogenesis)化學物質(zhì)引起或增進正常細胞發(fā)生惡性轉(zhuǎn)化并發(fā)展成為腫瘤的過程。具有這類作用的化學物質(zhì)稱為化學致癌物(chemicalcarcinogen).化學致癌研究的重要歷史事件

1761,JHill提出使用鼻煙可能會誘發(fā)鼻咽癌1775,PPott提出掃煙囪男童陰囊癌與煤煙過度暴露有關1895,LRehn首次報道從事苯胺染料生產(chǎn)的工人發(fā)生膀胱癌1914,TBoveri提出惡性腫瘤起源于存在染色體異常的單個細胞（這就是著名的癌癥體細胞突變理論和腫瘤單細胞克隆起源學說）

InitiatingEventCellProliferation(clonalexpansion)ProgressionCellProliferationCellProliferation

MalignancySecondMutatingEvent"N"MutatingEventInitiation

PromotionStagesofCarcinogenesisCellularandMolecularMechanismsinMultistageCarcinogenesis:

INITIATIONInitiatingeventinvolvescellulargenome–MUTATIONSTargetgenes:

-oncogenes/tumorsuppressorgenes

-signaltransduction

-cellcycle/apoptosisregulators“Simple”geneticchangesCellularandMolecularMechanismsinMultistageCarcinogenesis:PROMOTIONReversibleenhancement/repressionofgeneexpression:

-increasedcellproliferation

-inhibitionofapoptosisNodirectstructuralalterationinDNAbyagentoritsmetabolitesCellularandMolecularMechanismsinMultistageCarcinogenesis:

PROGRESSIONIrreversibleenhancement/repressionofgeneexpressionComplexgeneticalterations(chromosomaltranslocations,deletions,geneamplifications,recombinations,etc.)Selectionofneoplasticcellsforoptimalgrowthgenotype/phenotypeinresponsetothecellularenvironment“Complex”geneticchanges遺傳毒物對DNA和非DNA相互作用的機制正常細胞遺傳改變（突變）遺傳改變的細胞癌細胞異倍體細胞表遺傳干擾遺傳毒性致癌物非遺傳毒性致癌物遺傳毒性和非遺傳毒性致癌物在多階段致癌中的區(qū)別遺傳毒性和非遺傳毒性致癌物作用機制的比較

遺傳毒性致癌物非遺傳毒性致癌物遺傳毒性測試陽性陰性多階段致癌作用遺傳改變表遺傳改變第一階段基因突變細胞增殖染色體畸變再生生長因子刺激過氧化物酶體增殖細胞間間隙連接通訊基因組印記以后階段遺傳或表遺傳改變遺傳或表遺傳改變低劑量的劑量－反應關系無致癌性閾值線性劑量－反應曲線致癌性閾值S型劑量－反應曲線

致癌作用所引起的細胞變化可傳到子細胞

致癌作用可被非致癌因子所修飾

細胞增生是細胞癌變過程的重要階段

Thedevelopmentofcancerisa

multi-stepprocess

“Initiation”formsanearlyadenoma“Promotion”leadstoalateadenoma“Progression”leadsfirsttoacancerinsitu,thenonto…“Malignantconversion,”whichleadstotrueacarcinomaThissetofprocessesoftentakesYEARSGenotoxiccarcinogensincreasetumourfrequencyinanimalcancerbioassaypositiveresultsfrominvitroandinvivogenotoxicitytestseitherdirect-actingorindirectlyactinggenotoxiccarcinogensNon-genotoxiccarcinogensusuallyactastumorpromoterspositiveincancerbioassayinanimals,butnegativeingenotoxicitytestsThemechanismofcarcinogenicitymayincludethechronicinjuryandregenerationhormonalmechanismsincreaseinthecellproliferationordecreaseinthecelldeathintargetorganTheconceptofa“complete”vs.an“incomplete”carcinogenWhenoneforeignchemicalissuffienttocausecancer,eitherasadirectorindirectcarcinogen,itissaidtobecompleteWhenitrequiresatumorpromotertocausecancer,itisanincompletecarcinogenPromotorsarecompoundsthatinducecells,likethemutatedcancerinitiatorcell,togrowanddivide,makingmoreFifteenexamplekeyeventsrepresentingdiversecarcinogenicmodesofactionDNAreactivity(covalentbinding)GenemutationChromosomalbreakageAneuploidyEnzyme-mediatedeffectsonDNAdamageorrepairEpigeneticeffectsCellsignaling:nuclearreceptor-mediatedCellsignaling:otherthannuclearreceptor-mediatedImmuneresponsemodulationInflammationCytotoxicityandcompensatorycellproliferationMitogenicityChronicmetabolicorphysiologicoverloadNutrientdeficiencyrelatedInterferencewithintercellularcommunicationICHGuidelineS1BonTestingforCarcinogenicityofPharmaceuticalschoosingone2-yearrodentcarcinogenicitystudy(rat)

plusoneotherstudythatsupplementsthe2-yearstudyandprovidingadditionalinformationthatisnotreadilyavailablefromthe2-yearstudy:either(1)ashort-ormedium-terminvivorodenttestsystem

or(2)a2-yearcarcinogenicitystudyinasecondrodentspecies(mouse).theshort-ormedium-termmodelswasintendedtofocusontheuseofinvivomodelsprovidinginsightintocarcinogenicendpointssuchasinitiation–promotionrodentmodelsandmodelsofcarcinogenesisusingtransgenicorneonatalrodents藥物致癌性評價方法StipulatedRationaleforChoosingaShort-orMedium-TermTestSystemasSupplementtoOne2-YearBioassay?Themechanismofcarcinogenesisinthemodelshouldmostlikelyberelevanttohumans,andthereforetheuseofthemodelshouldbeapplicabletohumanriskassessment.?Theuseofthemodelshouldsupplementthe2-yearcarcinogenicitystudyanditshouldprovideadditionalinformationthatisnotreadilyavailablefromthe2-yearstudy.?Animalwelfare,animalnumbers,andoveralleconomyofthecarcinogenicevaluationprocessshouldbeconsidered.Two-yearCarcinogenesis“Bioassay”ProtocolCurrentGlobalCarcinogenicityStudyRequirementsStandardTissueListKidneyUrinarybladderAortaHeartTracheaLungsLiverGallbladderPancreasFatSalivaryglandSpleenCervicallymphnodeMesentericlymphnodeThymusTongueEsophagusStomachDuodenumJejunumIleumCecumColonMammaryglandSkinSkeletalmuscleSciaticnerveParathyroidThyroidAdrenalglandPituitaryProstateSeminalvesiclesTestesEpididymidesOvariesOviductsUterinehornsUterinebodyCervixVaginaBrainSpinalcordSternumRib/boneEyesHarderianglandsBMsmearNaresClitoral/preputialglandZymbal’sglandGrosslesions美國毒性病理學會（STP）建議致癌試驗進行組織病理學檢查的最基本的受檢內(nèi)容目錄Tumor-BearingAnimalsinControlGroupsfromRodentStudiesSource:J.K.Haseman(unpublishedsummaryofU.S.NTPdata).ComparativePercentIncidenceofPertinentNeoplasiainDifferentStrainsofRatsandMice(104WeeksOld)Note:F344,Fischer244rats;S-D,Sprague–Dawleyrats;B6C3F1,mice,(C57BL/6N+C3H/HeN)F1;CD-1,1CRCr:CD-1mice;NA,nonapplicable;theaveragenumberusedbyspecies/strain/genderwasinexcessof750animalsPreclinicalapproachesforassessingcarcinogenicpotentialTumorigenicityinhumans,nonhumanprimatesandrodentsSpontaneoustumorratesinthebreederandcontrolanimalsTheNeonatalMousePietraetal.(1959).Theneonatalmouseisoneofthealternativeinvivomodels,fordetectingthecarcinogenicpotentialofpharmaceuticals.ThisisinagreementwiththesuggestionsofICH,whichallowstheuseofonealternativestudyinplaceofoneofthe2-yearcarcinogenicitystudies.Whentreatmentbeginswithinthefirst24hoursoflife,thestudydesignisdescribedas“newbornmouse”.“neonatalmouse”includestestitemadministrationatdifferenttimepointsfrombirthtothreeweeksofage.Fujii(1991)reportedthattheneonatalmouseassayshowedasensitivityof85%andapositivepredictionrateof96%comparedtotheresultsoftheadultmouse2-yearcarcinogenicitystudy.Flammangetal.(1997)consideredthismodeltohavehighsensitivityandspecificitytodetectgenotoxiccarcinogensaswellaspresentingadvantagessuchasreducedtestarticlerequirements,decreasedanimalnumbersandcostsandareducedcompletiontime.Itdoesnotrespondtochemicalsactingviaepigeneticmechanisms.

McClainetal.(2001)reportedthatneonatalmicehavebeenshowntohaveareducedtimefortumorinduction,ahighermultiplicityofinducedtumors,alowerspontaneoustumorrateandanequivalentorhighersensitivitytocarcinogenswhencomparedtoadultmice.Thismodelalsorespondstoawiderangeofstructurallydissimilargenotoxiccompounds.Additionally,theneonatalmousepossessesthemajorityofthephaseIandIIbiotransformationliverenzymesinvolvedintheprocessesofactivationanddetoxificationofcarcinogensfromdifferentchemicalclasses.CD-1mice10to12weeksofage.Micewerecagedwith5femalespermaleandexaminedeachdayforthepresenceofavaginalcopulationplug.Femaleswereisolateduntildelivery,6litterswith4neonates/sex/litterwereassignedtoeachgroupduringthefirstweekafterbirth.Threeorfourdoselevels,avehicleandapositivecontrolwereused.

Groupsconsistedof24animals/sex/group.Theyweredosedonthebasisoftheiraveragebodyweight,ondays8and15ofage,usingdosevolumesofupto100and200μl,respectively.Doselevelswereselectedonthebasisoftheresultsobtainedindoserangefindingstudies,inwhichtheMTDortheMFD(MaximumFeasibleDose)forneonatalmice,weredetermined.Thepupswereweanedaround22daysofage,housed4/sex/cageandthenmaintaineduntil1yearofage,whentheyweresacrificed.DEN(diethylnitrosamine)atadosageof2mg/kgdissolvedinwaterwasusedasthepositivecontrol.Tg.AC(v-Ha-ras)TransgenicMouse8–9weeksoldGroupsof15mice/sex/dosewererandomlyassignedtothestudygroups.Thevehiclesusedfordrugsandpositivecontrolagentswereacetone,ethanolorDMSO.TPA(12-o-tetradecanoylphorbol-13-acetate)wasthepositivecontrolcompound26weeksHemizygousp53+/–KnockoutMouse6to10weeksold,GenotypeanalysiswasrecommendedpriortoassignmenttodosegroupsGroupsof15mice/sex/group,Threedoselevels,avehicleandapositivecontrolwereused.Twoadditionalgroupsof15wild-typemice/sex/groupreceivedthevehicleandthehighdosageofthetestcompound.p-Cresidineat400mg/kg/daybygavageincornoil(10ml/kg),orbenzeneat100mg/kg/daybygavageincornoil(5ml/kg)wererecommendedaspositivecontrols.18to24monthbioassaycarcinoGENOMICSDevelopmentofahighthroughputgenomics-basedtestforassessingge