[Effect of overexpression of Smad7 gene on cell proliferation].
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.
Huo
Yan-ying
YY
Department of, Institute of radiation medicine, Beijing Military Academy of Medical Sciences, Beijing 100850, China.
Zhang
Kai-tai
KT
Li
Bang-yin
BY
Xu
Qin-zhi
QZ
Duan
Rui-feng
RF
Hu
Ying-chun
YC
Xiang
Xiao-qiong
XQ
Li
Gang
G
Wu
De-chang
DC
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
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