简介:组蛋白甲基化是参予细胞的过程的一个多样的数组的重要epigenetic现象并且被发现了与癌症被联系。几的Recentidentification嘘一demethylases证明了那嘘一甲基化是一个可逆过程。通过一条候选人途径,我们化学上有简历作为H3K27demethylase识别了JMJD3。进HeLa房间的JMJD3的Transfection引起了整齐的乙醇H3K27的特定的减小,但是没在di-和单音的甲基H3K27上有效果,或嘘H3K4和H3K9上的一离氨酸methylations。Theenzymatic活动要求JmjC域和被建议了为余因子绑定重要的保存组氨酸。试管内生物化学的实验证明那JMJD3directly催化demethylation。另外,我们发现JMJD3起来在前列腺癌症,和它的表示调整了在变形前列腺癌症是更高的。因此,我们作为能够把整齐的乙醇组从移开的ademethylase识别了JMJD3嘘一H3离氨酸27并且起来在前列腺癌症调整了。
简介:流行性感冒的所有已知的子类型A病毒在野水鸟被维持,这些病毒的自然水库。流行性感冒A病毒被孤立从许多有改变病态和死亡率的动物种类。更重要地,流行性感冒A病毒与潜在地致命的结果在人引起呼吸疾病。在人的本地或全球的爆发被过量住院和死亡典型地描绘。在1997,H5N1子类型的高度病原的鸟的流行性感冒病毒在传给人的香港出现了,导致由鸟的流行性感冒病毒感染的人的死亡的首先记录的盒子。在越南,印度尼西亚,和泰国在家禽在2003年7月开始的新爆发,和高度病原的鸟的H5N1流行性感冒病毒后来在整个亚洲并且进欧洲和非洲传播了。这些病毒继续与高死亡率感染人并且引起隐约可见的世界范围的担心流行。而且,H5N1病毒爆发在整个亚洲在家禽工业上有破坏效果。因为H5N1病毒爆发看起来从南部的中国发源,我们这里在中国检验H5N1流行性感冒病毒,与他们的生物性质上的一个重音。
简介:Ionizingradiationisoneofthemosteffectivetoolsincancertherapy.Inapreviousstudy,wereportedthatproteintyrosinekinase(PTK)inhibitorsmodulatetheradiationresponsesinthehumanchronicmyelogenousleukemia(CML)celllineK562.Thereceptortyrosinekinaseinhibitor,genistein,delayedradiation-inducedcelldeath,whilenon-receptertyrosinekinaseinhibitor,herbimycinA(HMA)enhancesradiation-inducedapoptosis.Inthisstudy,wefocusedonthemodulationofradiation-inducedcelldeathbygenisteinandperformedPCR-selectsuppressionsubtractivehybridization(SSH)tounderstanditsmolecularmechanism.Weidentifiedhumanthymidinekinase1(TK1),whichiscellcycleregulatorygeneandconfirmedexpressionofTK1mRNAbyNorthernblotanalysis.ExpressionofTK1mRNAandTK1enzymaticactivitywereparallelintheirincreaseanddecrease.TK1isinvolvedinG1-Sphasetransitionofcellcycleprogression.Incellcycleanalysis,weshowedthatradiationinducedG2arrestinK562cellsbutitwasnotabletosustain.However,theadditionofgenisteintoirradiatedcellssustainedaprolongedG2arrestupto120h.Inaddition,theexpressionofcellcycle-relatedproteins,cyclinAandcyclinB1,providedtheevidencesofG1/SprogressionandG2-arrest,andtheirrelationshipwithTK1incellstreatedwithradiationandgenistein.TheseresultssuggestthattheactivationofTK1maybecriticaltomodulatetheradiation-inducedcelldeathandcellcycleprogressioninirradiatedK562cells.
简介:heterotrimericguanine核苷酸绑定蛋白质(G蛋白质)被表明了各种各样的发信号调停在植物的小径。然而,它在发信号的phytochromeA(phyA)的角色留下逃犯。在这研究,我们发现新调停phyA的显型指明了far-red照耀(FR)preconditioned房间死亡,它仅仅在跟随暴露到白光(WL)的FR-grown幼苗的胚轴发生。房间死亡在G变异的gpa1被减轻,但是与野类型(WT)比较在G变异的agb1加重了,在调停phyA的房间死亡小径的GPA1和AGB1的对抗角色的陈述语气。进一步的调查显示nonphotoconvertibleprotochlorophyllide(Pchlide633)的导致FR的累积,在暴露上产生反应的氧种类(ROS)到WL,为前提FR的房间死亡被要求。而且,ROS主要在叶绿体被检测用荧光灯探查。有趣地,到黑暗成年的幼苗的H2O2的申请导致类似于前提FR的房间死亡的显型。这表明ROS是为房间死亡的一个批评调停人。另外,我们观察到agb1比WT幼苗对H2O2更敏感,显示G蛋白质可以也修改到ROS应力的幼苗的敏感。一起拿这些结果,我们推断G蛋白质可以涉及表明小径调整Arabidopsis胚轴的前提FR的房间死亡的phyA。在phyA位于G蛋白质的参与下面发信号的可能的机制在这研究被讨论。
简介:<正>Usingsubtractioncloning,weidentifiedthehumanN-MycDownstream-RegulatedGene-2(hNDRG2),locatedat14q11.2,asacandidatetumorsuppressorgene.Semi-quantitativeRT-PCRshowedthattheexpressionofhNDRG2in15of27(56%)humanGBMtissuesandall6humanglioblastomacelllineswassignificantlylowerthanthatinthenormalbrain.TheexpressionofhNDRG2alsowasevaluatedin60lung-carcinomapatients.17of26casesofsquamouscarcinomaand4of11casesofsmallcelllungcancerdisplayed
简介:<正>WeandothershavefirmlyestablishedthatsurfaceIgMreceptor(sIgM-R)crosslinkingwithantibodiestotheiheavychain(anti-i)leadstogrowtharrestandapoptosisinaseriesofwellcharacterizedB-celllymphomas.Thisrequiresablationofc-Mycproteinexpressionandtheconcomitantinductionofthecyclin-dependent-kinaseinhibitor,p27Kip1.Thesignalingmechanismsregulatingc-Mycandp27Kip1proteinexpressionarepoorlyunderstood.However,werecentlyestablishedthatsIgM-Rmediateddown-modulationofthePI-3Kpathwaydirectlyaffectedc-Mycandp27Kip1expressionandaccuratelypredictedgrowtharrest
简介:Kr眉p像像素的因素8(KLF8)抄写因素在房间周期前进起一个关键作用,oncogenic转变,对间充质的转变和侵略上皮。然而,它的原子本地化信号(NLS)没被识别。有另外的KLFmonopartiteNLS(mNLS)和C2H2锌手指(ZF)的KLF8份额,哪个被显示了是为一些另外的KLF的NLS。在这份报告,用指导PCR的mutagenesis和immunofluorescent显微镜学,我们显示出mNLSs,任何单个ZF的删除,或变化的那混乱Zn2+有约束力或联系DNA主题没影响KLF8的原子本地化。删除>然而,从C终点的1.5ZF引起了KLF8的细胞质的累积。令人惊讶地,氨基酸(aa)的删除151-200区域几乎从原子核消除了KLF8。有PKC禁止者的S165A,K171E或K171R变化,或处理导致了部分细胞质的累积。Co-immunoprecipitation证明KLF8与importin-交往了,这个相互作用要求了ZF主题。aa1-150或201-261区域的删除独自没改变原子本地化。BrdU加入和cyclinD1倡导者酶试金作为野类型的KLF8证明在原子本地化的KLF8异种有缺陷者不能支持DNA合成或cyclinD1倡导者激活。一起拿,这些结果建议KLF8有二NLS,一包围S165和K171并且另外的是二双人脚踏车ZF,它为KLF8原子本地化和它的细胞的功能的规定是批评的。
简介:Thenon-classicalHLAclassIantigenHLA-GisanimmunemodulatorwhichinhibitsthefunctionsofTcells,NKcells,andtheDendriticcells(DC).Asaresult,HLA-Gexpressioninmalignantcellsmayprovidethemwithamechanismtoescapetheimmunesurveillance.Inmelanoma,HLA-Gantigenexpressionhasbeenfoundin30%ofsurgicallyremovedlesionsbutinlessthan1%ofestablishedcelllines.OnepossiblemechanismunderlyingthedifferentialHLAGexpressioninvivoandinvitroisthattheHLA-Ggeneisepigeneticallyrepressedinmelanomacellsinvitro.Totestthishypothesis,wetreatedtheHLA-GnegativemelanomacelllineOCM-1AwiththeDNAmethyltransferaseinhibitor5-aza-2'-deoxycytidine(5-AC)andanalyzedwhetherHLA-Gexpressioncanberestored.OurdatastronglysuggestthatHLA-GissilencedasaresultofCpGhypermethylationwithina5'regulatoryregionencompassing220bpupstreamofthestartcodon.Aftertreatment,HLA-GmRNAexpressionwasdramaticallyincreased.WesternblotandflowcytometryshowedthatHLA-Gproteinwasinduced.Interestingly,HLA-Gcellsurfaceexpressiononthe5-ACtreatedOCM-1AcellsismuchlessthanthatontheHLA-GpositiveJEG-3cellswhileasimilaramountoftotalHLA-Gwasobserved.Possiblemechanismsforthedifferencewereanalyzedinthestudysuchascellcold-treatment,peptideloadingandantigenprocessingmachinerycomponents(APM)aswellasβ2microglobulin(β2-m)expression.DatarevealedthattheAPMcomponentcalreticulinmightbeinvolvedinthelowerHLA-GsurfaceexpressiononOCM-1Acells.Takentogether,ourresultsindicatedthatDNAmethylationisanimportantepigeneticmechanismbywhichHLA-Gantigenexpressionismodulatedinmelanomacellsinvitro.Furthermore,tothefirsttime,wehypothesizedthatthedeficiencyofcalreticulinmightbeinvolvedinthelowHLA-Gsurfaceexpressiononthe5-ACtreatedOCM-lAcells.
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.