title: [Study of effects of HBV X gene and As2O3 on expression and activity of p53 in HepG2 cells with shRNA].
abstract: OBJECTIVE
  To delineate the effects of HBV X gene and of As(2)O(3) on p53 expression and activity in HepG2 cells by shRNA-mediated RNA interference (RNAi).
  
  
  METHODS
  HepG2 cells and cells with stable expression of HBV X gene, HepG2-X, were treated with 2 micromol/L As(2)O(3), and the corresponding untreated cells were used as controls. Cell and nuclear lysates were extracted. Total level and the relative activity absorbance of p53 were detected by modified ELISA. HBV X gene sequence-specific shRNA expression vectors, Xi-S1 and Xi-S2, and sequence-unrelated control Xi-S3 were transfected into HepG2-X. The effect of As(2)O(3) on p53 expression and activity were retested.
  
  
  RESULTS
  Total p53 level was up-regulated and its relative activity ratio was enhanced by As(2)O(3) in HepG2 and HepG2-X cells. The total p53 level induced by As(2)O(3) was further up-regulated by HBX expression, while its relative activity was significantly suppressed. The suppression was removed after HBX expression was suppressed by shRNA.
  
  
  CONCLUSIONS
  As(2)O(3) could up-regulate p53 expression and enhance its activity. shRNA-mediated RNA interference is conveniently being used in studies on the effect of HBV X gene expression on p53 expression and activity. HBV X expression could up-regulate p53 gene expression level induced by As(2)O(3), while it suppressed the activity of p53.
authors.affiliation: Liver Disease Research Center, Second Xiangya Hospital, Central-South University, Changsha, 410011, China.
authors.forename: Xing-E
authors.initials: XE
authors.lastname: He
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Lei
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.forename: Wen-Long
authors.initials: WL
authors.lastname: Wang
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Luo
authors.forename: Jun
authors.initials: J
authors.lastname: Liang
mesh_terms: D017209:Apoptosis; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D015870:Gene Expression; D056945:Hep G2 Cells; D006515:Hepatitis B virus / Q000235:genetics; D006801:Humans; D010087:Oxides / Q000494:pharmacology*; D034741:RNA, Small Interfering; D015534:Trans-Activators / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D001152:Arsenicals; D010087:Oxides; D034741:RNA, Small Interfering; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D000077237:Arsenic Trioxide