学科分类
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11 个结果
  • 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。

  • 标签: 组蛋白 甲基化物 前列腺癌 临床
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  • 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.

  • 标签: 感应现象 HLA-G 基因表达 黑色素瘤 肿瘤细胞 OCM-1A
  • 简介:Uponencounteringtheantigen(Ag),theimmunesystemcaneitherdevelopaspecificimmuneresponseofenteraspecificstateofunresponsiveness,tolerance.TheresponseofBcellstotheirspecificAgcanbeactivationandproliferation,leadingtotheimmuneresponse,oranergyandactivation-inducedcelldeath(AICD),leadingtotolerance.AICDinBlymphocytesisahighlyregulatedeventinitiatedbycrosslinkingoftheBcellreceptor(BCR).BCRengagementinitiatesseveralsignalingeventssuchasactivationofPLCγ,Ras,andPI3K,whichgenerallyspeaking,leadtosurvival.However,intheabsenceofsurvivalsignals(CD40orIL-4Rengagement),BCRcrosslinkingcanalsopromoteapoptoticsignaltransductionpathwayssuchasactivationofeffectorcaspases,expressionofpro-apoptoticgenes,andinhibitionofpro-survivalgenes.ThecomplexinterplaybetweensurvivalanddeathsignalsdeterminestheBcellfateand,consequently,theimmuneresponse.

  • 标签: B淋巴细胞 B细胞受体 AICD 激活诱发细胞死亡 mIgM 细胞生长停滞
  • 简介:ApoptosisproducedinBcellsthroughFas(APO-1,CD95)triggeringisregulatedbysignalsderivedfromothersurfacereceptors:CD40engagementproducesupregulationofFasexpressionandmarkedsusceptibilitytoFas-inducedcelldeath,whereasantigenreceptorengagement,orIL-4Rengagement,inhibitsFaskillingandinsodoinginducesastateofFas-resistance,eveninotherwisesensitive,CD40-stimulatedtargets.SurfaceimmunoglobulinandIL-4RutilizeatleastpartiallydistinctpathwaystoproduceFas-resistancethatdifferentiallydependonPKCandSTAT6,respectively.Further,surfaceimmunoglobulinsignalingforinducibleFas-resistancebypassesBtk,requiresNF-κB,andentailsnewmacromolecularsynthesis.TerminaleffectorsofBcellFas-resistanceincludetheknownanti-apoptoticgeneproducts,Bcl-XLandFLIP,andanovelanti-apoptoticgenethatencodesFAIM(FasApoptosisInhibitoryMolecule).faimwasidentifiedbydifferentialdisplayandexistsintwoalternativelysplicedforms;faim-Sisbroadlyexpressed,butfaim-Lexpressionistissue-specific.TheFAIMsequenceishighlyevolutionarilyconserved,suggestinganimportantroleforthismoleculethroughoutphylogeny.InducibleresistancetoFaskillingishypothesizedtoprotectforeignantigen-specificBcellsduringpotentiallyhazardousinteractionswithFasL-bearingTcells,whereasautoreactiveBcellsfailtobecomeFas-resistantandaredeletedviaFas-dependentcytotoxicity.InadvertentoraberrantacquisitionofFas-resistancemaypermitautoreactiveBcellstoescapeFasdeletion,andmalignantlymphocytestoimpedeanti-tumorimmunity.

  • 标签: B淋巴细胞 FAS介导 细胞凋亡 FAIM FLIP CD40
  • 简介:<正>ThesusceptibilityofprimaryBcellstoFas(APO-1,CD95)-mediatedapoptosisisregulatedbysignalsderivedfromadditionalsurfacereceptors.CD40engagementproducesupregulationofFasexpressionandinducesmarkedsensitivitytoFas-inducedcelldeath,whereasBcellantigenreceptor(BCR)engagementinhibitsFaskillingandtherebyproducesFas-resistance,eveninotherwisesusceptible,CD40-stimulatedtargets.BCRsignalingforinducibleFas-resistancedevelopsoveraperiodof12hoursanddependson

  • 标签: 初级B淋巴细胞 Fas介导细胞凋亡 耐受性 信号转导
  • 简介:被象染色体冷凝作用,面向双性人的锭子形成,染色体大会离子,分离和胞质分裂那样的一系列紧安排的事件精确通过有丝分裂调整。染色体运动被和位于着丝点以内的一个专业化染色体领域的锭子微导管的相互作用在有丝分裂期间管理。这个专业化区域,叫了kinetochore,是为锭子微导管着丝点的地点协会。除了用作在染色体和锭子微导管之间的一个物理连接,kinetochore通过微导管马达和定位在或在它附近的锭子集会检查点(囊)传感器在chromosomal分离展出一个活跃角色[例如,1]。

  • 标签: 细胞周期蛋白B1 交响乐 管弦乐队 有丝分裂 导体
  • 简介:<正>WeandothershavefirmlyestablishedthatsurfaceIgMreceptor(sIgM-R)crosslinkingwithantibodiestotheiheavychain(anti-i)leadstogrowtharrestandapoptosisinaseriesofwellcharacterizedB-celllymphomas.Thisrequiresablationofc-Mycproteinexpressionandtheconcomitantinductionofthecyclin-dependent-kinaseinhibitor,p27Kip1.Thesignalingmechanismsregulatingc-Mycandp27Kip1proteinexpressionarepoorlyunderstood.However,werecentlyestablishedthatsIgM-Rmediateddown-modulationofthePI-3Kpathwaydirectlyaffectedc-Mycandp27Kip1expressionandaccuratelypredictedgrowtharrest

  • 标签: CH12B细胞淋巴瘤 细胞生长阻滞 细胞凋亡 PI-3K通路 信号转导 IgM受体抗体