简介:死亡联系域的蛋白质Daxx施加包括调停的许多报导功能经由激活c6月N终端从FasL发信号到apoptosisapoptosis的kinase(JNK),正式就职和抑制,和染色质改变的规定。它原来从酵母被克隆用船边交货对相似物体之连续感觉而形成心像口的细胞内部的尾巴的二混血儿的屏幕诱饵。而许多起始的报告仍然保持争论,Daxx在一系列压力信号包括UVirradiation,过氧化氢治疗和TGF-β治疗触发的apoptosis的规定起重要作用,是清楚的。在这评论,我们在Axinbeing上集中连接Daxx到p53的一个拴住的因素。
简介:TherearetwopossibleoutcomeswhenDNAdamageoccursinnormalmammaliancells:eitherinductionofcell-cyclecheckpointwhichinhibitstheprogressofthecellcyclesaswellasactivatesDNArepairpathways,oractivationofapoptosistoeliminatedamagedcells.Thep53tumour-suppressorgeneplaysakeyroleinselectingthesepathways.Inourpresentworks,thehumangastriccancercelllineAGSwastreatedwithtripchlorolide,apotentantitumorcompoundpurifiedfromaChineseherbTripterygiumWilfordiiHook.Singlecellgelelectrophoresis(Cometassay)showedthatthetreatmentoftripchlorolideresultedinDNAdamageinAGScells.ThedamagedAGScellswentthroughapoptosis,whichwastime-anddose-dependent.
简介:Recentstudiesindicatethatcell-cyclecheckpointsaretightlycorrelatedwiththeregulationofapoptosis,inwhichp53playsanimportantrole.OurpresentworksshowthattheexpressionofE6/E7oncogenesofhumanpapillomavirusinHeLacellsisinhibitedinthepresenceofanti-tumorreagenttripchlorolide(TC),whichresultsintheup-regulationofp53inHeLacells.Interestingly,underthesameTC-treatment,thecellsattheearlyS-phasearemoresusceptibletoapoptosisthanthoseatthemiddleS-phasealthoughp53proteinisstabilizedtothesamelevelinbothsituations.Significantdifferenceisexhibitedbetweenthetwospecifiedexpressionprofiles.Furtheranalysisdemonstratesthatanti-apoptoticgenesurvivinisup-regulatedbyp53intheTC-treatedmiddle-Scells,whereasitisdown-regulatedbyp53intheTC-treatedearly-Scells.Takentogether,thepresentstudyindicatesthatthedifferentialp53-regulatedexpressionofsurvivinatdifferentstagesofthecellcycleresultsindifferentcellularoutputsunderthesameapoptosis-inducer.
简介:OverexpressionandactivationofHER-2/neu(alsoknownasc-erbB-2),aproto-oncogene,wasfoundinabout30%ofhumanbreastcancers,promotingcancergrowthandmakingcancercellsresistanttochemo-andradio-therapy.Wild-typep53iscrucialinregulatingcellgrowthandapoptosisandisfoundtobemutatedordeletedin60-70%ofhumancancers.Andsomecancerswithawild-typep53donothavenormalp53function,suggestingthatitisimplicatedinacomplexprocessregulatedbymanyfactors.Inthepresentstudy,weshowedthattheoverexpressionofHER-2/neucoulddecreasetheamountofwild-typep53proteinviaactivatingPI3Kpathway,aswellasinducingMDM2nucleartranslocationinMCF7humanbreastcancercells.BlockageofPI3KpathwaywithitsspecificinhibitorLY294002causedG1-Sphasearrest,decreasedcellgrowthrateandincreasedchemo-andradio-therapeuticsensitivityinMCF7cellsexpressingwild-typep53.However,itdidnotincreasethesensitivitytoadriamycininMDA-MB-453breastcancercellscontainingmutantp53.OurstudyindicatesthatblockingPI3KpathwayactivationmediatedbyHER-2/neuoverexpressionmaybeusefulinthetreatmentofbreasttumorswithHER-2/neuoverexpressionandwild-typep53.