title: [Effect of overexpression of Smad7 gene on cell proliferation].
abstract: OBJECTIVE
  To study the effect of overexpression of Smad7 gene on cell proliferation in human bronchial epithelial cell lines.
  
  
  METHODS
  Human bronchial epithelial cell lines, BEP2D and BERP35T2 cells, were cotransfected with the mammalian expression vectors PCISmad7.neo and pMyc-SEAP, the latter was ac-myc cis-acting enhancer element fused with alkaline phosphatase (SEAP) reporter gene. Expression of c-myc, p15 and p21 mRNA was detected by RT-PCR before and after stable transfection of Smad7 into BEP2D and BERP35T2 cells in order to study the regulation of TGF-beta-mediated growth inhibition.
  
  
  RESULTS
  After BEP2D and BERP35T2 cells transfected with Smad7, the transcriptional activity of c-myc was significantly increased. Smad7 overexpressing cells showed upregulation of c-myc expression and downregulation of p15 and p21 expression, which contributed to the loss of TGF-beta responses in these cells.
  
  
  CONCLUSIONS
  Overexpression of Smad7 may facilitate cell proliferation by antagonizing TGF-beta-mediated antiproliferative gene responses.
authors.affiliation: Department of, Institute of radiation medicine, Beijing Military Academy of Medical Sciences, Beijing 100850, China.
authors.forename: Yan-ying
authors.initials: YY
authors.lastname: Huo
authors.forename: Kai-tai
authors.initials: KT
authors.lastname: Zhang
authors.forename: Bang-yin
authors.initials: BY
authors.lastname: Li
authors.forename: Qin-zhi
authors.initials: QZ
authors.lastname: Xu
authors.forename: Rui-feng
authors.initials: RF
authors.lastname: Duan
authors.forename: Ying-chun
authors.initials: YC
authors.lastname: Hu
authors.forename: Xiao-qiong
authors.initials: XQ
authors.lastname: Xiang
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: De-chang
authors.initials: DC
authors.lastname: Wu
mesh_terms: D001980:Bronchi / Q000166:cytology*; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D050762:Cyclin-Dependent Kinase Inhibitor p15 / Q000096:biosynthesis / Q000235:genetics; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000096:biosynthesis / Q000235:genetics; D004847:Epithelial Cells / Q000166:cytology*; D006801:Humans; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction; D051906:Smad7 Protein / Q000096:biosynthesis* / Q000235:genetics; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D050762:Cyclin-Dependent Kinase Inhibitor p15; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016271:Proto-Oncogene Proteins c-myc; D051906:Smad7 Protein; D016212:Transforming Growth Factor beta