title: [HBx gene down-regulates miR-192 expression and inhibits apoptosis of human hepatoma cell line HepG2].
abstract: OBJECTIVE
  To explore the mechanism by which HBV X gene(HBx) inhibits apoptosis of human hepatoma cell line HepG2 in terms of miRNA.
  
  
  METHODS
  Three cell lines were prepared: HepG2 cells stably transfected with HBx (HepG2/HBx), HepG2 cells stably transfected with pcDNA3.1 (HepG2/pcDNA3.1) and HepG2 cells. Flow cytometry was adopted to measure the apoptosis of these three cells and Taqman fluorescence quantitative PCR was used to examine miR-192 expression. After HepG2 cells was transfected with miR-192, the apoptosis was analyzed by flow cytometry and the expressions of p53 and PUMA at mRNA and protein levels were evaluated by SYBR Green quantitative PCR and Western blot, respectively.
  
  
  RESULTS
  Compared with HepG2/pcDNA3.1 cells (11.46% ± 0.69%) and HepG2 cells (12.5% ± 0.66%), the apoptosis rate of HepG2/HBx cells (2.37% ± 0.35%) was significantly reduced (F = 171.722, P < 0.01). The level of miR-192 was 49.1% ± 5.9% in HepG2 cells, which was dramatically down-regulated (F = 14.319, P = 0.019) as compared to the other two groups (HepG2/pcDNA3.1: 98.0% ± 8.9%; HepG2: 100%). Compared with HepG2 cells transfected with miR-NC (10.74% ± 1.15%), transfection of miR-192 into HepG2 cells led to increased apoptosis (15.74% ± 1.17%) (F = 18.415, P = 0.013) and higher p53 and PUMA expressions at mRNA (p53: 1.68 ± 0.12 vs 0.90 ± 0.09, F = 43.115, P = 0.003, PUMA: 1.66 ± 0.10 vs 0.98 ± 0.06, F = 22.541, P = 0.009) and protein (p53: 3.07 vs 1, PUMA: 2.13 vs 1) levels.
  
  
  CONCLUSIONS
  HBx could inhibit apoptosis of HepG2 cells through down-regulation of miR-192 which induces apoptosis of HepG2 cells.
authors.affiliation: Institute of Liver Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Qiong-hui
authors.initials: QH
authors.lastname: Xie
authors.forename: Xing-xing
authors.initials: XX
authors.lastname: He
authors.forename: Ying
authors.initials: Y
authors.lastname: Chang
authors.forename: Xiang
authors.initials: X
authors.lastname: Jiang
authors.forename: Ju-sheng
authors.initials: JS
authors.lastname: Lin
mesh_terms: D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D015536:Down-Regulation; D005814:Genes, Viral; D056945:Hep G2 Cells; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D035683:MicroRNAs / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D054334:Viral Regulatory and Accessory Proteins
chemical_list: C546783:MIRN192 microRNA, human; D035683:MicroRNAs; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein