title: Down-regulated P53 by siRNA increases Smad4's activity in promoting cell apoptosis in MCF-7 cells.
abstract: BACKGROUND
  Wildtype p53 and Smad4 are important suppressor genes in tumor genesis and development. The mutation in p53 gene is closely related to the early formation of breast cancer. In this research, we try to explore the status of Smad4 in breast cancer cell line MCF7 after knocking down p53.
  
  
  METHODS
  MCF-7 was bought from American Type Culture Collection (ATCC). Cells were cultured in Dulbecco's Modified Eagle Medium (DMEM) with 10% fetal bovine serum (FBS) in incubator containing 5% CO2 at 37°C. In this study we apply to analytical methods such as growth ratio analysis in vitro, immunoblot analysis, flow cytometry for cell cycle analysis, RNA extraction and Real-Time PCR and data analysis.
  
  
  RESULTS
  The results indicated that specific down regulating of p53 can significantly increase the expression of Smad4 in cancer cell line MCF7 and promote cell apoptosis. In MCF7 cell line p53 gene is negatively related to Smad4 in great extent.
  
  
  CONCLUSIONS
  In our study, we detect the expression and function of Smad4 by suppressing p53 expression in MCF7, trying to figure out the relationship and signaling pathway between them. In this study, we try to found the affection of p53 on Smad4, so as to induce apoptosis in tumor cell, achieving the goal of targeted cancer prevention and treatment.
authors.affiliation: Department of Plastic Surgery, Fudan University, Shanghai, China. bjin_wu@hotmail.com
authors.forename: B
authors.initials: B
authors.lastname: Wu
authors.forename: W
authors.initials: W
authors.lastname: Li
authors.forename: C
authors.initials: C
authors.lastname: Qian
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
authors.forename: W
authors.initials: W
authors.lastname: Xu
authors.forename: J
authors.initials: J
authors.lastname: Wu
mesh_terms: D017209:Apoptosis; D002453:Cell Cycle; D015536:Down-Regulation; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D034741:RNA, Small Interfering / Q000235:genetics*; D051901:Smad4 Protein / Q000502:physiology*; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D034741:RNA, Small Interfering; C497796:SMAD4 protein, human; D051901:Smad4 Protein; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53