title: [5-Aza-CdR regulates the expression of RASSF1A gene in human gastric cancer cell line and inhibits the growth of cells].
abstract: OBJECTIVE
  To investigate the effect of demethylating agent 5-Aza-CdR (5-aza-2'- deoxycytidine) on demethylation and transcription-regulating of RASSF1A gene in gastric cancer cell SGC7901 in vitro, as well as on the growth inhibition of cells.
  
  
  METHODS
  After SGC7901 cells were treated with 5-Aza-CdR, MTT assay, flow cytometry, and Annexin V-FITC staining were performed to analyze the cell proliferation, cell cycle and apoptotic rate respectively. Methylation- specific PCP (MSP), RT-PCR and Western blotting were used to detect methylation state, expression of mRNA and protein of RASSF1A gene.
  
  
  RESULTS
  After SGC7901 cells were treated with different concentrations of 5-Aza-CdR, the cell growth was inhibited(P<0.05), the cell cycle was blocked at G(1) phase, and the apoptotic rate increased significantly(P<0.05). Hypermethylation was detected in the promoter region of RASSF1A gene in SGC7901 cells, and no expression of RASSF1A mRNA and protein was found. After treated with 5-Aza-CdR, demethylation occurred in RASSF1A gene,which subsequently induced re-expression of this gene at both mRNA and protein level.
  
  
  CONCLUSIONS
  Demethylating agent 5-Aza-CdR can regulate demethylation and re-expression of RASSF1A gene in gastric cancer cell SGC7901,and inhibit its growth.
authors.affiliation: Department of Surgical Oncology, The First Affiliated Hospital, China Medical University, Shenyang 110001, China.
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Shen
authors.forename: Dong-Qiu
authors.initials: DQ
authors.lastname: Dai
authors.forename: Yue
authors.initials: Y
authors.lastname: Teng
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Liu
mesh_terms: D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D019175:DNA Methylation; D000077209:Decitabine; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins; D000077209:Decitabine; D001374:Azacitidine