title: Anti-proliferation effects and molecular mechanisms of action of tetramethypyrazine on human SGC-7901 gastric carcinoma cells.
abstract: OBJECTIVE
  To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action.
  
  
  METHODS
  The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-xBp65, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription- polymerase chain reaction (RT-PCR) and western blotting.
  
  
  RESULTS
  TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-xBp65 and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-xBp65 and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01).
  
  
  CONCLUSIONS
  TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-xBp65, cyclinD1 and p16 may also play important roles in the regulation mechanisms.
authors.affiliation: First Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing, China E-mail : jajoffice@163.com.
authors.forename: Ai-Jun
authors.initials: AJ
authors.lastname: Ji
authors.forename: Sheng-Lin
authors.initials: SL
authors.lastname: Liu
authors.forename: Wen-Zheng
authors.initials: WZ
authors.lastname: Ju
authors.forename: Xin-En
authors.initials: XE
authors.lastname: Huang
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002277:Carcinoma; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D019938:Cyclin D1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16; D015536:Down-Regulation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D016328:NF-kappa B / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011719:Pyrazines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C530104:CCND1 protein, human; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D016328:NF-kappa B; D009363:Neoplasm Proteins; D011719:Pyrazines; D012333:RNA, Messenger; D019938:Cyclin D1; C017953:tetramethylpyrazine