《肿瘤表观遗传学》PPT课件

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1、Epigeneticsincancer肿瘤世界癌症现状全球(2010年)809万人死亡1303万新发病例5肝癌1肺癌7食道癌3结肠癌2乳腺癌4胃癌6宫颈癌CancerCancer6宫颈癌5结肠癌8鼻咽癌1肺癌2肝癌7乳腺癌3胃癌4食道癌268万新发病例中国癌症现状197万人死亡中国（2010）Whatcausescancer?Carcinogenesis.Somefactorstoconsider…HeredityImmunityChemicalPhysicalViralBacterialLifestyleHeredityGenesisol

2、atedforseveralclassicfamilialcancersyndromes:RB1(retinoblastoma)APC(familialpolyposis)HumanNonPolyposisColonCancer(HNPCC)BRCA1&2(breastcancer)p53(manycancers)抑癌基因p53ColleenA.BradyandLauraD.Attardi,p53ataglance，JournalofCellScience,2010,123:2527-2532Exposuretocarcinogens,fai

3、lureofDNArepair,andprogressivegeneticinstabilityleadtoaccumulationofmutationsthatdrivecancerdevelopment,growth,andmetastases.Subcloneswithnewmutationsmaybecomedominantwithinmetastasesorwithinpersistentorrecurrentcancerdepositsthroughselectivepressuresexertedbycytotoxicortar

4、getedchemotherapies.CancerEpigeneticsSincethediscoveryofthefirstrecurrentmutationsinoncogenesandtumorsuppressorgenes,ithasbeenclearthatcanceris,inlargepart,ageneticdisease.Globalchangesintheepigeneticlandscapeareahallmarkofcancer.WhatisEpigentics?遗传学genetics基因组印迹源自双亲的两个等位基因

5、中一个不表达或表达很弱。不遵循孟德尔定律同卵双胞胎表观遗传WhyYourDNAIsn’tYourDestiny?Thenewfieldofepigeneticsisshowinghow your environmentand yourchoicescaninfluence your geneticcode—andthatof your kids表观遗传学(Epigenetics)基因的DNA序列不发生改变的情况下，基因的表达水平与功能发生改变，并产生可遗传的表型一门新兴的遗传学分支遗传与表观遗传表观遗传学的特点：可遗传的，即这类改变通过有丝分

6、裂或减数分裂，能在细胞或个体世代间遗传；可逆性的基因表达调节，也有较少的学者描述为基因活性或功能的改变；没有DNA序列的改变或不能用DNA序列变化来解释。拉马克1809年发表的《动物哲学》：用进废退这种后天获得的性状是可以遗传的表观遗传学变化具有可遗传性NattD,RubinCJ,WrightDetal.Heritablegenome-widevariationofgeneexpressionandpromotermethylationbetweenwildanddomesticatedchickens.BMCgenomics2012;13:

7、59.ConclusionsOurresultsshowthatepigeneticvariationisinheritedinchickens,andwesuggestthatselectionoffavourableepigenomes,eitherbyselectionofgenotypesaffectingepigeneticstates,orbyselectionofmethylationstateswhichareinheritedindependentlyofsequencedifferences,mayhavebeenanim

8、portantaspectofchickendomestication.DowenRH,PelizzolaM,SchmitzRJetal.Widespreaddyn