title: [AXIN1-related CSRNP1 mRNA expression and its transcriptional regulation in TGF-β1-induced tumor cells].
abstract: OBJECTIVE
  To investigate AXIN1-related CSRNP1 gene expression and the mechanism of its transcriptional regulation in TGF-β1-induced tumor cells.
  
  
  METHODS
  Human lung carcinoma A549 cells or human prostate cancer PC3 cells were treated with TGF-β1 at different doses (0, 20, 40, and 80 ng/ml) or at 20 ng/ml for 0, 8, 12, or 24 h, and the dose and time effect of TGF-β1 on CSRNP1 mRNA expression in the tumor cells were evaluated with real-time RT-PCR. A549 cells were also treated with TGF-β1 and cycloheximide to clarify whether CSRNP1 expression induced by TGF-β1 required de novo protein synthesis. A549 cells transfected with pcDNA3.1, flag-SMAD3, or flag-SMAD3-mu, after serum starvation, were treated with or without TGF-β1 (20 ng/mL) for 24 h, and the overexpression of wild-type SMAD3 and dominant negative SMAD3-mu mutant were confirmed by Western blotting. The effect of SMAD3 or SMAD3-mu overexpression on CSRNP1 mRNA expression was also measured by real-time RT-PCR.
  
  
  RESULTS
  In both A549 and PC3 cells, TGF-β1 dose- and time-dependently stimulated CSRNP1 expression, which required de novo protein synthesis in A549 cells. Overexpression of wild-type SMAD3 significantly increased the expression of CSRNP1 mRNA induced by TGF-β1, while overexpression of dominant negative SMAD3 mutant remarkably reduced CSRNP1 mRNA expression in response to TGF-β1 in A549 cells.
  
  
  CONCLUSIONS
  TGF-β1 may contribute to CSRNP1 expression through SMAD3 activation and downstream signaling in tumor cells.
authors.affiliation: Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China. E-mail: fandeng@smu.edu.cn.
authors.forename: Fan
authors.initials: F
authors.lastname: Deng
authors.forename: Songyu
authors.initials: S
authors.lastname: Li
authors.forename: Wanfu
authors.initials: W
authors.lastname: Xu
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Zou
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Ke
authors.forename: Fangyin
authors.initials: F
authors.lastname: Zeng
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D060466:Axin Protein / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction; D051900:Smad3 Protein / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
chemical_list: C555451:AXIN1 protein, human; D051017:Apoptosis Regulatory Proteins; D060466:Axin Protein; C434543:CSRNP1 protein, human; D012333:RNA, Messenger; C497790:SMAD3 protein, human; D051900:Smad3 Protein; D053773:Transforming Growth Factor beta1