title: Epigenetic alterations of BRG1 leads to cancer development through its nuclear-cytoplasmic shuttling abnormalities.
abstract: SWI/SNF is a multiprotein chromatin remodeling complex important for gene regulation. BRG1 and its close relative BRM, have ATPase activity necessary for transcriptional regulation by conformational change of nucleosomes. Due to this role on gene expression, several members of SWI/SNF complex including BRG1 and BRM function as a tumor suppressor or negative regulator of cellular proliferation. On the other hand, the shuttling of proteins between nucleus and cytoplasm is strongly involved in the regulation of cell cycle and proliferation. Many of tumor suppressor gene (TSG)s including p53, BRCA1, ING1 play some of their functions through nucleocytoplasmic shuttling. Abnormalities related with this process abrogate the subcellular localization of the TSGs and lead to cancer development. We recently demonstrated BRG1 as a TSG in oral cancer. Our analysis also revealed an interesting finding that one of the splicing forms of BRG1 is selectively lost in cancer tissue as compared to normal counterparts. Our further analysis revealed a putative nuclear retention signal domain for this splicing form. In this article, we speculate the possible mechanism for the inactivation of BRG1 gene in oral cancer through an abnormality in its subcellular localization.
authors.affiliation: Department of Oral Pathology and Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikatacho, Okayamashi 700-8558, Japan.
authors.forename: Esra
authors.initials: E
authors.lastname: Gunduz
authors.forename: Mehmet
authors.initials: M
authors.lastname: Gunduz
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nagatsuka
authors.forename: Levent
authors.initials: L
authors.lastname: Beder
authors.forename: Kadir
authors.initials: K
authors.lastname: Demircan
authors.forename: Ryo
authors.initials: R
authors.lastname: Tamamura
authors.forename: Omer Faruk
authors.initials: OF
authors.lastname: Hatipoglu
authors.forename: Naila
authors.initials: N
authors.lastname: Mahmut
authors.forename: Naoki
authors.initials: N
authors.lastname: Katase
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Naomoto
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Nagai
mesh_terms: D021581:Active Transport, Cell Nucleus; D017398:Alternative Splicing; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism*; D044127:Epigenesis, Genetic; D006801:Humans; D008957:Models, Genetic; D009369:Neoplasms / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; D014157:Transcription Factors; C084108:SMARCA4 protein, human; D004265:DNA Helicases