title: Sequential recruitment of PCAF and BRG1 contributes to myogenin activation in 12-O-tetradecanoylphorbol-13-acetate-induced early differentiation of rhabdomyosarcoma-derived cells.
abstract: Myogenin and its upstream regulator MyoD are known to be required for myogenic cell differentiation. Although both of them can be expressed in rhabdomyosarcoma-derived RD cells, the cells are unable to undergo full-scale terminal myogenic differentiation. 12-O-Tetradecanoylphorbol-13-acetate (TPA) has been found to be functional in the induction of RD cell differentiation, whereas its mechanism is not fully understood. By using quantitative real-time-based chromatin immunoprecipitation and real-time reverse transcription-PCR-based promoter activity assays, we examined the activation mechanism of the myogenin gene during TPA-induced differentiation of the RD cells. We have shown that a histone acetyltransferase PCAF and ATPase subunit BRG1 of the SWI/SNF chromatin remodeling complex are sequentially recruited to the promoter of the myogenin gene. Both PCAF and BRG1 are also involved in the activation of the myogenin gene. In addition, we have found that the p38 mitogen-activated protein kinase is required for BRG1 recruitment in TPA-mediated myogenin induction. We propose that there are two distinct activation steps for the induction of myogenin in TPA-induced early differentiation of RD cells: 1) an early step that requires PCAF activity to acetylate core histones and MyoD to initiate myogenin gene expression, and 2) a later step that requires p38-dependent activity of the SWI/SNF remodeling complex to provide an open conformation for the induction of myogenin. Our studies reveal an essential role for epigenetic regulation in TPA-induced differentiation of RD cells and provide potential drug targets for future treatment of the rhabdomyosarcoma.
authors.affiliation: National Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China.
authors.forename: Zhao-yong
authors.initials: ZY
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Xin
authors.initials: X
authors.lastname: Gao
authors.forename: Jian-yi
authors.initials: JY
authors.lastname: Lu
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Kepeng
authors.initials: K
authors.lastname: Wang
authors.forename: Mo-bin
authors.initials: MB
authors.lastname: Cheng
authors.forename: Ning-hua
authors.initials: NH
authors.lastname: Wu
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhenguo
authors.initials: Z
authors.lastname: Wu
authors.forename: Yu-fei
authors.initials: YF
authors.lastname: Shen
mesh_terms: D000107:Acetylation; D002273:Carcinogens / Q000494:pharmacology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D002843:Chromatin / Q000502:physiology; D004265:DNA Helicases / Q000378:metabolism*; D015195:Drug Design; D044127:Epigenesis, Genetic / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic; D051548:Histone Acetyltransferases / Q000378:metabolism*; D006801:Humans; D018008:Myogenin / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000502:physiology; D012208:Rhabdomyosarcoma / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*; D050880:p300-CBP Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000099224:p300-CBP-Associated Factor
chemical_list: D002273:Carcinogens; D018797:Cell Cycle Proteins; D002843:Chromatin; D004265:DNA Helicases; D051548:Histone Acetyltransferases; D018008:Myogenin; D009687:Nuclear Proteins; D013755:Tetradecanoylphorbol Acetate; D014157:Transcription Factors; D050880:p300-CBP Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; D000099224:p300-CBP-Associated Factor; C084108:SMARCA4 protein, human