title: [Effects of Poly I:C in inducing growth inhibition and apoptosis of human hepatocellular carcinoma cells].
abstract: OBJECTIVE
  To explore the effect and mechanism of Poly I:C in inducing growth inhibition and apoptosis of human hepatocellular carcinoma SMMC-7721 cells.
  
  
  METHODS
  SMMC-7721 cells were treated with different doses of Poly I:C for 24, 48, and 72 h, and the cell growth inhibition rate was analyzed with CCK-8 assay. The cell cycle and the apoptosis were analyzed using flow cytometry with Annexin-V and PI staining, and quantitative RT-PCR analysis were used to detect the expression of TLR3, TRIF, and IFN-beta mRNA in cells.
  
  
  RESULTS
  In the cells exposed to Poly I:C at low, moderate, and high doses, the inhibitory rates was the highest in high-dose Poly I:C group, and at a given Poly I:C dose, prolonged exposure resulted in significantly increased cell growth inhibition rate (P<0.05). Flow cytometry showed that Poly I:C induced cell apoptosis in a time- and dose-dependent manner and significantly increased the percentage of G1-phase cells as compared with that in the control group. The mRNA level of TLR3, TRIF, and IFN-beta were also increased following Poly I:C treatment in comparison with the control group.
  
  
  CONCLUSIONS
  Poly I:C can induce significant growth inhibition and apoptosis of SMMC-7721 cells in a dose- and time-dependent manner possibly by causing cell cycle arrest and TLR3 signaling pathway activation that leads to IFN-beta production and cell apoptosis.
authors.affiliation: Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, China. fly5151@sohu.com
authors.forename: Peng
authors.initials: P
authors.lastname: Shen
authors.forename: Ting-Wan
authors.initials: TW
authors.lastname: Jiang
authors.forename: Hui-Qi
authors.initials: HQ
authors.lastname: Lu
authors.forename: Ling-Zhen
authors.initials: LZ
authors.lastname: Zhang
authors.forename: Huan-Xing
authors.initials: HX
authors.lastname: Han
authors.forename: Rong-Cheng
authors.initials: RC
authors.lastname: Luo
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism; D008113:Liver Neoplasms / Q000473:pathology*; D011070:Poly I-C / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011949:Receptors, Cholecystokinin / Q000378:metabolism; D015398:Signal Transduction; D051196:Toll-Like Receptor 3 / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D011949:Receptors, Cholecystokinin; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D016899:Interferon-beta; D011070:Poly I-C