title: [Hepatitis C virus F protein-mediated inhibition of hepatoma cell proliferation].
abstract: OBJECTIVE
  To investigate the biological function of the hepatitis C virus (HCV)-encoded F protein in hepatocytes.
  
  
  METHODS
  The full-length F gene was amplified by PCR from HCV genotype 1a and cloned into plasmid pSEB-3Flag by restriction enzyme digestion and ligation. Hepatoma cell lines, Huh7 and SMMC7721, were transfected with the resultant recombinant pSEB-3Flag-F or the original pSEB-3Flag (negative control) and screened with the selective antibiotic, blasticidin. Stable F gene and protein expression was verified by RT-PCR analysis. Analysis of cell growth and cell cycle was carried out by MTS assay, crystal violet staining and flow cytometry.
  
  
  RESULTS
  Huh7 and SMMC7721 cells transfected with pSEB-3Flag-F plasmid (Huh7-F and SMMC7721-F, respectively) uniquely expressed the F gene and protein. The Huh7-F and SMMC7721-F cells showed significantly decreased proliferation rates, compared to the respective control groups. A similar HCV F-mediated growth-inhibiting activity was observed by the cell viability assay. Furthermore, cell cycle analysis revealed that the S-phase distribution was much lower in Huh7-F (47.12%) and SMMC7721-F (30.75%) cells than in the respective controls (55.35% and 33.23%, respectively) (P less than 0.05).
  
  
  CONCLUSIONS
  Stable expression of the HCV F gene reduced the in vitro proliferation rate of hepatoma cell lines, indicating that the F protein may function as a growth inhibitor of infected cells.
authors.affiliation: Chongqing Medical University, Chongqing, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhou
authors.forename: Jiao
authors.initials: J
authors.lastname: Liu
authors.forename: Qing-mei
authors.initials: QM
authors.lastname: Chen
authors.forename: Xiao-ling
authors.initials: XL
authors.lastname: Shan
authors.forename: Lin-lin
authors.initials: LL
authors.lastname: Chen
authors.forename: Hui-qin
authors.initials: HQ
authors.lastname: Quan
authors.forename: Ni
authors.initials: N
authors.lastname: Tang
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D016174:Hepacivirus / Q000235:genetics; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014758:Viral Core Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D014758:Viral Core Proteins; C433031:hepatitis C protein F, Hepatitis C virus