title: [Effect of hydroquinone on expression of ubiquitin-ligating enzyme Rad18 in human L-02 hepatic cells].
abstract: OBJECTIVE
  To investigate the effects of hydroquinone (HQ) on expression of ubiquitin-ligating enzyme Rad18 in human hepatic cells (L-02), and to explore the role and possible mechanism of Rad18 involved in toxicity of HQ to hepatic cells.
  
  
  METHODS
  After L-02 hepatic cells were exposed to HQ with various concentrations (0, 5, 10, 20, 40, 80 and 160 micromol/L) for 24 h, cell survival rate was measured by MTT assay; DNA impairment was evaluated by single cell gel electrophoresis (SCGE); The expression levels of Rad18 mRNA and protein were detected by Real-time fluorescent quantitative polymerase chain reaction (QPCR) technique and Western blot method respectively.
  
  
  RESULTS
  HQ with concentration from 0 to 80 micromol/L had little effect on survival rate of L-02 (P > 0.05); Whereas the survival rate in the group of 160 micromol/L was significantly lower than in the control with the significant difference (P < 0.01) after treated with HQ for 24 h; The higher dose of HQ presented, the more degrees of olive tail moment (OTM) were produced and a dose-dependent relationship was shown. HQ in a low concentration (0 to approximately 40 micromol/L) could induce increase in the expression of Rad18 mRNA and protein which was in proportion to the increment of HQ concentration; the expression of Rad18 mRNA was enhanced increasingly, while the expression of Rad18 protein unchanged basically once the concentration of HQ exceeded 40 micromol/L; Besides, there was a positive correlation between OTM and the expression level of Rad18 mRNA (r = 0.919, P < 0.01).
  
  
  CONCLUSIONS
  HQ could regulate up the expression of Rad18 in L-02 hepatic cells.
authors.affiliation: Department of Preventive Medicine, Gannan Medical College, Ganzhou 341000, China.
authors.forename: Gong-hua
authors.initials: GH
authors.lastname: Hu
authors.forename: Zhi-xiong
authors.initials: ZX
authors.lastname: Zhuang
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Huang
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.forename: Jian-hui
authors.initials: JH
authors.lastname: Yuan
authors.forename: Lin-qing
authors.initials: LQ
authors.lastname: Yang
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004249:DNA Damage / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism*; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D006873:Hydroquinones / Q000633:toxicity*; D044767:Ubiquitin-Protein Ligases
chemical_list: D004268:DNA-Binding Proteins; D006873:Hydroquinones; C485954:RAD18 protein, human; D044767:Ubiquitin-Protein Ligases; C031927:hydroquinone