肿瘤细胞信号转导

如何阅读文献在肿瘤学方面有哪些好的杂志如何快速阅读文献以获取知识论文的主要结构肿瘤的分子信号转导+genomicinstabilityfromHanahanandWeinberg2000SignalTransductionandCancerLectureI:GrowthFactorsandReceptorsOutline:WhatisSignalTransduction? WhatareGrowthFactors?HowdotheycontributetonormalST?HowisthisSTderegulatedinCancer?LectureI:GrowthFactorsandReceptorsWhatisSignalTransduction?SignalTransductionistheprocessbywhichacellconvertsanextracellularsignalintoaresponse.Involvedin:Cell-cellcommunicationCell’sresponsetoenvironmentIntracellularhomeostatsis-internalcommunicationGenericSignallingPathwaySignalReceptor(sensor)TransductionCascadeTargetsResponseAlteredMetabolismMetabolicEnzymeGeneRegulatorCytoskeletalProteinAlteredGeneExpressionAlteredCellShapeorMotilityAdaptedfromMolecularBiologyoftheCell,(2002),4thedition,Albertsetal.ComponentsofSignallingWhatcanbetheSignal?ExternalmessagetothecellPeptides/Proteins-GrowthFactorsAminoacidderivatives-epinephrine,histamineOthersmallbiomolecules-ATPSteroids,prostaglandinsGases-NitricOxide(NO)PhotonsDamagedDNAOdorants,tastantsSignal=LIGANDLigand-Amoleculethatbindstoaspecificsiteonanothermolecule,usuallyaprotein,iereceptorComponentsofSignallingWhatareReceptors?Sensors,whatthesignal/ligandbindstoinitiateSTCellsurface

Intracellular

HydrophillicLigandCell-SurfaceReceptorPlasmamembraneHydrophobicLigandCarrierProteinIntracellularReceptorNucleusAdaptedfromMolecularBiologyoftheCell,(2002),4thedition,Albertsetal.Ligand-gatedionchannelCellSurfaceReceptorTypes:CellSurfaceReceptorTypes:G-ProteinCoupledReceptorCellSurfaceReceptorTypes:egGrowthFactorReceptorsEnzyme-linkedReceptorGrowthFactorsLigandswhichbindenzymelinkedreceptorsSignaldiversecellularresponsesincluding:ProliferationDifferentiationGrowthSurvivalAngiogenesisCansignaltomultiplecelltypesorbespecificFactorPrincipalSourcePrimaryActivityCommentsPDGFplatelets,endothelialcells,placentapromotesproliferationofconnectivetissue,glialandsmoothmusclecellstwodifferentproteinchainsform3distinctdimerforms;AA,ABandBBEGFsubmaxillarygland,Brunnersglandpromotesproliferationofmesenchymal,glialandepithelialcells

TGF-

commonintransformedcellsmaybeimportantfornormalwoundhealingrelatedtoEGFFGFwiderangeofcells;proteinisassociatedwiththeECMpromotesproliferationofmanycells;inhibitssomestemcells;inducesmesodermtoforminearlyembryosatleast19familymembers,4distinctreceptorsNGF

promotesneuriteoutgrowthandneuralcellsurvivalseveralrelatedproteinsfirstidentifiedasproto-oncogenes;trkA(trackA),trkB,trkCErythropoietinkidneypromotesproliferationanddifferentiationoferythrocytes

TGF-

activatedTH1cells(T-helper)andnaturalkiller(NK)cellsanti-inflammatory(suppressescytokineproductionandclassIIMHCexpression),promoteswoundhealing,inhibitsmacrophageandlymphocyteproliferationatleast100differentfamilymembersIGF-IprimarilyliverpromotesproliferationofmanycelltypesrelatedtoIGF-IIandproinsulin,alsocalledSomatomedinCIGF-IIvarietyofcellspromotesproliferationofmanycelltypesprimarilyoffetaloriginrelatedtoIGF-IandproinsulinGrowthFactorReceptorsMostgrowthfactorsbindReceptorTyrosineKinasesGrowthFactorReceptorActivationIRTKRS/TKGrowthFactorReceptorActivationIIGrowthsignalautonomy,Insensitivitytoanti-growthsignals,Resistancetoapoptosis:Uncouplecell’sgrowthprogramfromsignalsintheenvironment.Growthfactorsinnormalcellsserveasenvironmentalsignals.GrowthFactorSTandCancerGrowthfactorsregulategrowth,proliferation,andsurvival.Theseareallderegulatedincancer.HanahanandWeinberg,(2000)HallmarksofCancer,Cell(100)57GrowthfactorswithOncogenicPotentialPDGF,originallyshowntoregulateproliferation,wasalsoshowntohavehomologytov-sis,thesimiansarcomavirus.OtherviraloncogenesencodedproteinproductsthatweregrowthfactorsthatoftenoverexpressedincancersuchasTGF-a.Autocrinesignallingleadstoderegulatedgrowth.

PDGFfamily Neurotrophins

Achain NGF Bchain(c-sis) BDNFFGFFamily NT3

acidicFGF Cytokines(Hematopoietic) basicFGF IL-2EGFFamily IL-3

EGF M-CSF TGF-a GM-CSF

GFReceptorswithOncogenicPotentialEGFR,kinaseactivitystimulatedbyEGF-1andTGF-ainvolvedincellgrowthanddifferentiation,waslinkedviasequencehomologytoaknownavianerythroblastosisvirusonocgene,v-erbB.Sincethen,manyoncogeneshavebeenshowntoencodeforGFRs.EGFRfamily InsulinReceptorfamily

erbB1(c-erbB) IGF-1(c-ros) erbB2(neu) Neurotrophins

FGFFamily NGFR(trk)

FGFR-1(fig) BDNFR(trk-B) FGFR-2(K-sam) NT3R(trk-C)PDGFRFamily

CSF-1R(c-fms) SLFR(c-kit) InductionofcancerbyalternationsinseveraltypesofproteinsinvolvedincellgrowthcontrolSignalTransductionandCancerLectureII:IntracellularSignallingOutline:Whataresomesignallingpathways? Whataretheircellbiologicaloutputs?Howdotheseresultinthecancerphenotype?Howcanweexploitsignallingpathwaysfortherapy?GenericSignalTransductionRTKSignalTransductionSignalTransductionDownstreameffectorsProteinSignalingModules(Domains)SH2andPTBbindtotyrosinephosphorylatedsitesSH3andWWbindtoproline-richsequencesPDZdomainsbindtohydrophobicresiduesattheC-terminioftargetproteinsPHdomainsbindtodifferentphosphoinositidesFYVEdomainsspecificallybindtoPdtlns(3)P(phosphatidylinositol3-phosphate)MechanismsforActivationofSignalingProteinsbyRTKsActivationbymembranetranslocationActivationbyaconformationalchangeActivationbytyrosinephosphorylationMechanismsforAttenuation&TerminationofRTKActivationLigandantagonistsReceptorantagonistsPhosphorylationanddephosphorylationReceptorendocytosisReceptordegradationbytheubiquitin-proteosomepathwayActivationofMAPKPathwaysbyMultipleSignalsGrowth,differentiation,inflammation,apoptosis->tumorigenesisOverviewofMAPKSignalingPathwaysTheMAPKPathwayActivatedbyRTKRTKST-PI3KpathwayPProto-oncogenesthatEncodeforSignallingProteinsSerine/ThreonineKinasesc-raffamilyaktNon-receptorTyrosineKinasessrcablReceptorassociatedbindingproteinsc-rasfamilyRasrecruitsRaftothemembraneSTintermediatescanbetargetsforanti-cancerdrugsKinases:RafSTintermediatescanbetargetsforanti-cancerdrugsKinases:Bcr-AblCellPatterningCellGrowthBMPWnt01FGFHedgehog02WhataretheessentialelementsofanySignalingcascade?Signal–ligand添加标题DiffusibleorTethered添加标题Receptor添加标题Transmembrane(exceptforlipidsolubleligands)添加标题Transducers-effectors添加标题Targets添加标题GenesorCellularcomponents添加标题WntSignalingPathwayWntsSignalFrizzledsReceptorb-cateninTransducers-effectorsGenescytoskeletonTargetsTheSignal:Wnt1•morphogen-diff.Concentrationsofligandelicitdifferent2responsesinequivalentcells3•morphogenicmovementsandcellfatedeterminants4•“Beposterior”-cellfate5•“divide”-proliferation6•developmentalabnormalitieswhengenedeletedWingless(Wg):DrosophilaSharmadescribesawinglessmutationin1973√Sharma,1973Wingless-anewmutantinD.melanogaster.D.I.S.50:134√SharmaandChopra,1976,Effectofthewingless(wg1)mutationonwingandhalteredevelopmentinDrosophilamelanogaster.Dev.Biol.48:461-465LateritwasclonedpositionallyIntegrationofMMTVcausesmammarytumorsinmiceTumorsarepregnancydependentMMTVhasasteroidenhancerMicedevelopbreasttumorsbutonlyduringlactationGenewasdesignated-Int-1(integrationofMMTV)OtherinsertionsitesoccurredatotherGFse.g.FGFTumorsexhibitdominantGainofFunctionLesson:Ectopicactivationofagene>hyperplasia=OncogeneWingless+int-1=WntFlywgandMouseInt-1arehomologsGenesarecloned.Sequenceissimilar

102030405060708090100HWnt-1MGLWALLPSWVSTTLLLALTALPAALAANS----SGR-----WWGIVNIASSTNLLTDSKSLQLVLEPSLQLLSR-KQRRLIRQNPGILHSVSGGLQSAVFlyWgMDISYIFVICLMALCSGGSSLSQVEGKQKSGRGRGSMWWGIAKVGEPNNITP-----IMYMDPAIHSTLRRKQRRLVRDNPGVLGALVKGANLAI110120130140150160170180190200HWnt-1RECKWQFRNRRWNCPT---APGPHLFGKIVNRGCRETAFIFAITSAGVTHSVARSCSEGSIESCTCDYRR--RGP----------GGPDWHWGGCSDNIDFlyWgSECQHQFRNRRWNCSTRNFSRGKNLFGKIVDRGCRETSFIYAITSAAVTHSIARACSEGTIESCTCDYSHQSRSPQANHQAGSVAGVRDWEWGGCSDNIG210220230240250260270280290300HWnt-1FGRLFGREFVDSGEKGRDLRFLMNLHNNEAGRTTVFSEMRQECKCHGMSGSCTVRTCWMRLPTLRAVGDVLRDRFDGASRVLYGN---------------FlyWgFGFKFSREFVDTGERGRNLREKMNLHNNEAGRAHVQAEMRQECKCHGMSGSCTVKTCWMRLANFRVIGDNLKARFDGATRVQVTNSLRATNALAPVSPNA310320330340350360370380390400HWnt-1RGSN----------------------------------------------------------RASR----------AELLRLEPEDPAHKPPSPHDLVYFFlyWgAGSNSVGSNGLIIPQSGLVYGEEEERMLNDHMPDILLENSHPISKIHHPNMPSPNSLPQAGQRGGRNGRRQGRKHNRYHFQLNPHNPEHKPPGSKDLVYL410420430440450460470HWnt-1EKSPNFCTYSGRLGTAGTAGRACNSSSPALDGCELLCCGRGHRTRTQRVTERCNCTFHWCCHVSCRNCTHTRVLHECLNFlyWgEPSPSFCEKNLRQGILGTHGRQCNETSLGVDGCGLMCCGRGYRRDEVVVVERCACTFHWCCEVKCKLCRTKKVIYTCLNTheSignal:Wnt•Secretedproteinligandsof80-100aa•Lipidmodified

Latestbreakthrough(2003):purificationofactiveWnt requiresorganicextraction!!•Shortrangeacting•Sticktoextracellularmatrix•Gradients---->morphogenic?•multipleWnts(19inhuman/mouseand7inDrosophila)Wntssignalthroughserpentinereceptors2classesofsignalingreceptorsCatalyticTyrosineKinaseReceptors[RTKs]Ser/ThrKinaseReceptors[BMPs]Serpentine/G-protein-coupled-receptors(GPCRs)/7-transmembraneWntsßadrenergic,dopamine,epinepherineetcTheReceptor:Frizzled•corereceptorforWnts•seven-passtransmembraneproteins•probablyG-proteincoupledreceptors•multipleFrizzleds(10inhuman/mouseand4inDrosophila)•anewlyidentifiedco-receptorforWnts•singlepasstransmembraneprotein•relatedtofamilyoflipoproteinreceptorsLRP/arrow:WntSignalingregulatesgeneexpressionandcellpolaritycanonicalWntFzWntFzLrpLrpnon-canonical/~rnusse/pathways/cell2/CanonicalWntsignalingin2005b-cateninisthecytoplasmic-nuclearsignalingmediatorb-catenin章节一b-catenin•armadilloinDrosophila

geneticsdeterminedthatitfunctioneddownstreamofWg•b-catenininmammaliansystemidentifiedascomponent ofcelladhesionjunctions•subcellularlocalizationofproteincontroversialforyears•purificationofb-cateninandcloningofgenein1991byP.McCraeandB.Gumbinershowedthatarmadilloandb-cateninareorthologuesThetransducer/effector:Armadillorepeatstructureofb-cateninLEF/TCFWntCK1GSK-3bAPCb-cateninaxinFrizzledLRPE-cadherinWntsignalingpathwayLiuetal.2002.Cell108:837.Complicatedphosphorylationcontrolsb-cateninstabilityHowdoesb-cateninreachtargetgenes?•LEF/TCFtranscriptionfactors•HMG(HighMobilityGroup)proteins•mammalianLEF-1andTCF-1identifiedinTlymphocytes in1991•twomoremembersclonedbylowstringencyscreeningofLibrariesanddegeneratePCRin1993•b-cateninwasusedinayeasttwo-hybridassayandLEF-1wasclonedasaninteractingproteinin1997 -endpointofthepathwaydetermined -mergedtwoindependentgroupsofscientists -subcellularlocalizationofb-cateninfinallysettledGeneralStructureofLEF/TCFTranscriptionFactorsb-cateninbindingCo-repressorbindingDNAbinding/bendingalt.COOHTCF-1TCF-3TCF-4NLSHMGNLEF-1BBBEEE94%96%99%55%52%64%TargetGenesofWntSignaling•cellcycleregulatorsandtranscriptionfactors -c-MYC -cyclinD1•tissuespecificgenes•tissueremodelingproteins -matrixmetalloproteinases -ephrinreceptorsandligands -adhesionproteins•angiogenesis -VEGFIntheabsenceofWntsignaling:NLSHMGNLEF-1BNLSHMGNdnLEF-1BGrouchoLEF/TCFWntGSK-3baxinFrizzledLRPAPCLEF/TCFLEF/TCFLEF/TCFLEF/TCFLEF/TCFLEF/TCFLEF/TCFLEF/TCFActivationofLEF-1targetgenescantransformcellsAoki,M.etal.1999.Proc.Natl.Acad.Sci.USA.96:139-144anchorage-independentgrowthcontactinhibitioncolonyformation/~rnusse/wntwindow.htm•IdentifiedbyJoannaGrodenandRayWhiteasatumorsuppressorgenesufferingLOHinfamilieswithveryhighratesofcoloncancer.•TruncationmutationsorlossoftheentiregeneoccursinmostAdenomatousPolyposisColi01•Sporadiccoloncancers02Hereditarycolorectalcancer(~15%)FamilialAdenomatousPolyposis(FAP)-<1%allcolorectalCAGermlinemutationsinAPCgene.Acceleratedtumourinitiation.RatelimitingstepissomaticmutationinotherAPCalleleMedianageofcancerdiagnosis42yrs.Despitesharedgenotypes,notallclinicaldiseaseissimilar(diseasemodifyinggenesorenvironmentalinfluences?)Oftendevelopextracolonicmanifestations.MousemodelAPCminHereditaryNonPolyposisColorectalCancer(HNPCC)-2-4%allcolorectalCAMutationsinDNAmismatchrepair(MMR)genes-germline-genome-wide microsatelliteinstability(MI).Earlycluescamefrombacterialstudies.Adenomasformatthesamerateasthegeneralpopulation,butthereisacceleratedtumourprogressionMedianageofcancerdiagnosisalso42yrs.FAP HNPCC Sporadic Sporadic Adenomas CancersIncidence1:7000 1:500 1in2 1in20APCmutation>90% >80% >80%(prevalance) (germline) (somatic) (somatic)MMRdeficiency >90% <3% 13%(prevalance)MMRgene >70% ? ~65%mutationsAPCshuttlemode-speculativelWntsignalingandcolorectalcancerMajorfunctionofAPCistheregulationofcelluarb-cateninlevels.ActivationofwntpathwayincoloncancerdrivescellproliferationTcf-responsivegenes:c-myc,cyclinD1,PPARd-fibronectinandmatrilysin(anextracellularmetalloproteinase)CNSMutationclusterregion-allresultinproteintruncationRacGEFGraybars-b-cateninbindingsites.APCmayplayaroleincell-celladhesion(Cadherins)Redbars-Axin/Conductinbindingsites(lostinmutations)Redarrows-nuclearexportsignals.MutantAPCaccumulatesinthenucleusAsefbindingactivatesRacatmembranes,inducingmembraneruffling thereforepossiblyaffectingcellmotilityMT-microtubulebindingsite.APCisinvolvedinlinkingmicrotubulestokinetochores thereforemutationscancontributetogenomicinstabilityb-catenindestructioncomplexAxinandAPCphysicallyinteract.APCmutationsincolonCAlackAxin bindingsites.-b-cateninbindstoAPC.APC/AxincomplexregulatesGSK3bkinaseactivity.BindstoAxin. ThereforeAxinmayserveascaffoldingfunction.AxinandAPCarealsoGSK3bsubstrates,andphosphorylationincreases theirabilitytobindb-catenin.HowwntsignalsinhibitGSK3bactivityisunclear.Dishevellediscritical.WntsignalresultsindephosphorylationofAxinPP2AdephosphorylatesAxin.ItscatalyticsubunitbindsAxinwhileits regulatorysubunitbindsAPC.TheregulatorysubunitofPP2A ismutatedinasubsetofcolonCA.HowisPP2Aactivityregulated?-Whereistheintracellularlocalizationofthedestructioncomplex?APCmutationWildtypeAPCAPCmutationsresultinincreasedgenomicinstabilityMouseModel-APCminMultipleintestinalneoplasia(min).APCgenemutation.Truncatedproteinat codon850.Htzhaveincreasedpropensityfortumors.Tumorsacquiresomaticmutation inwildtypeAPCallele.TumorslocatedinupperGItract(notcolorectal).Geneticbackgroundofmouseinfluencestumorload(?modifiers). MOM-1-possiblysecretedphospholipaseA2.APC1638TlacksC-terminaldomainthatbindstubulin,EB1-likeproteins. homozygousEScellshavehighdegreeofchromosomalinstability buthomozygousmicedoNOTexhibitincreasedtumorsusceptibilityCooperatingOncogenes.Cyclooxygenase2:deletionofCOX-2genesuppressesintestinalpolyposis inAPCD716mice.COX-2levelsareincreasedinpremalignantpolyps. ButCOX-2isexpressedininterstitialcellsnotintestinalepithelium.Smad4:deletionofSmad4inAPCD716miceresultedinmoreaggressive tumors(compoundhtzmice). HighlightstheroleofTGFsignalintumorprogression.DNAmethyltransferase:compoundhtzhavereducedpolypnumbers (epigeneticevents?).TumourProgressionTGF

signalingmutationsreceptorIImutationsdetectedinregionsofhighgradedysplasia butabsentinadenomas.Intumourswithmicrosatelliteinstability(MI)mutationscorrelatewithprogressionofadenomastocancermutationsinTGFsignalingcomponents(e.g.,smad4)-nonMItumor accelerate/worsenmurine(APCmin)intestinalcancermodelCell-celladhesivecomplexmutations-cadherins,b-catenins,others?3.Metalloproteinaseactivation-matrilysinisatcf-responsivegenecompactionoftheearlyembryo-morphogeneticmovementofcells-establishmentofcellfates,andpolaritylossofcell-cellandcell-matrixrecognitiontissueinvasionmotilitynormaldevelopmentcancerprogression“epithelialmesenchymal”transitionHedgehogSignalingPathwayGenesTargets04CubitusInterruptusTransducers-effectors03PatchedReceptor02HedgehogSignal01单击此处可添加副标题单击此处添加大标题内容•MutationsinHedgehogsignalinginhumansembryosyieldscyclopia(aformofholoprosencephaly)imagesareonlyforthestout-hearted.•Inadults,mutationsinHedgehogsignalinggivesphenotypesinstemcellandprogenitorpopulations.Increasedsignalinggivestumors,lesssignalinggivesshort-livedstemcells•MostrecentadvanceisthatmanytumorsshowelevatedHhsignaling.Cyclopamine(firstobtainedfromthecornlily)haspromisefortherapeuticinterventionofcancer.TheSignal:Hedgehog•Lipidmodifiedwithcholesterol•Sticktoextracellularmatrix•Secretedproteinligand-heavilyprocessed•Shortrangeacting•Gradients---->morphogenic?•threeligandsinmammals:Indian,Desert,Sonic010203040506Thehedgehoggeneencodesanovelmembrane-linkedligandimportantforlocalpatterningofmanytissues.Theprimarytranslationproductcontainsasignalpeptidethatiscleavedtoproducea45kDapolypeptideprecursor.Cleavageofthissecretedprecursorproducesa20kDaN-terminalfragmentassociatedwiththeplasmamembraneandwithinductiveactivityplusa25kDafragment.TheN-terminalfragmentbecomestetheredtothemembraneviaahydrophobiccholesterolmoiety(itdoesn’tcontainanyhydro