title: SW13 cells can transition between two distinct subtypes by switching expression of BRG1 and Brm genes at the post-transcriptional level.
abstract: The human adrenal carcinoma cell line, SW13, has been reported to be deficient in both BRG1 and Brm expression and therefore is considered to lack a functional SWI/SNF complex. We found that the original cell line of SW13 is composed of two subtypes, one that expresses neither BRG1 nor Brm (SW13(vim-)) and the another, which does express both (SW13(vim+)). The presence of BRG1 and Brm in SW13 correlates completely with the cellular ability to express such genes as vimentin, collagenase, c-met, and CD44 that were under the control of a transcription factor, AP-1, which was shown previously to require a functional SWI/SNF complex for its transactivating activity. Transient treatment with inhibitors of histone deacetylase induced a stable transition of SW13(vim-) to a cell type indistinguishable from SW13(vim+), suggesting that these two subtypes are epigenetically different. Run-on analysis indicated that, unlike these four genes driven by AP-1, transcription of the BRG1 and Brm genes in SW13(vim-) are initiated at a frequency comparable with SW13(vim+). In both SW13(vim-) and SW13(vim+) cells, the BRG1 and Brm genes were transcribed through the entire gene at a similar efficiency, indicating that their expression was completely suppressed at the post-transcriptional level in SW13(vim-) cells. We would like to propose that SW13 can spontaneously transition between two subtypes by switching expression of BRG1 and Brm at the post-transcriptional level.
authors.affiliation: Division of Host-Parasite Interaction, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Mitsue
authors.initials: M
authors.lastname: Yamamichi-Nishina
authors.forename: Taiji
authors.initials: T
authors.lastname: Ito
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Mizutani
authors.forename: Nobutake
authors.initials: N
authors.lastname: Yamamichi
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hideo
authors.initials: H
authors.lastname: Iba
mesh_terms: D015152:Blotting, Northern; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000235:genetics*; D002467:Cell Nucleus / Q000378:metabolism; D018920:Coculture Techniques; D004247:DNA / Q000378:metabolism; D004265:DNA Helicases; D029721:Drosophila Proteins; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics*; D010957:Plasmids / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D015534:Trans-Activators / Q000096:biosynthesis* / Q000235:genetics*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*; D014407:Tumor Cells, Cultured
chemical_list: D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D018960:Hyaluronan Receptors; D009687:Nuclear Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; C086469:brm protein, Drosophila; D012313:RNA; D004247:DNA; C084108:SMARCA4 protein, human; D004265:DNA Helicases