亚硒酸钠对亚砷酸致HepG2细胞DNA损伤的影响

Effects of Selenium on Arsenic Acid-induced DNA Damage in HepG2 Cells

目的观察硒对砷致HepG2细胞DNA损伤的影响。方法以人肝肿瘤细胞HepG2为靶细胞,分别以亚硒酸钠(2.5、5.0和10.0μmol/L)和亚砷酸(1.56、3.125、6.25、12.5和25.0μmol/L)为受试物处理HepG2细胞,再以亚硒酸钠与亚砷酸联合处理HepG2细胞,应用单细胞凝胶电泳试验检测亚硒酸钠、亚砷酸单独及联合染毒对HepG2细胞DNA的损伤作用。结果与溶剂对照相比,10.0μmol/L亚硒酸钠使HepG2细胞DNA的Olive尾矩显著增加(P<0.05),2.5、5.0μmol/L亚硒酸钠使Olive尾矩有减少的趋势,但差异无显著性意义。6.25、12.5和25.0μmol/L亚砷酸均使HepG2细胞DNA的Olive尾矩显著增加(P<0.01或P<0.05),且呈现剂量依赖关系。25.0μmol/L亚硒酸钠与12.5μmol/L亚砷酸联合作用与12.5μmol/L亚砷酸单独作用相比,Olive尾矩减小,差异有极显著性意义(P<0.01)。5.0μmol/L亚硒酸钠与25.0μmol/L亚砷酸联合作用与25.0μmol/L亚砷酸单独作用相比,Olive尾矩增加,差异有显著性意义(P<0.05)。结论亚硒酸钠对亚砷酸诱导的HepG2细胞DNA损伤的减弱或增强作用与亚硒酸钠和亚砷酸浓度有关。

Objective To explore the effects of selenium on arsenic-induced DNA damage in HepG2 cells.Methods As target cells,HepG2 cells were exposed to sodium selenite at the concentrations of 2.5,5.0 and 10.0 μmol/L and to arsenious acid at the concentrations of 1.56,3.125,6.25,12.5 and 25.0 μmol/L respectively.Then the cells were exposed simultaneously to sodium selenite and arsenious acid to explore the effects of co-exposures of sodium selenite and arsenious acid on DNA damage in HepG2 cells.Single cell gel electrophoresis(SCGE) was applied for quantitative analysis of DNA damage.Results Sodium selenite(10.0 μmol/L) could significantly increase DNA Olive tail moment in HepG2 cells in comparison with the solvent control(P<0.05).DNA Olive tail moment was decreased in HepG2 cells treated with sodium selenite of 2.5 and 5.0 μmol/L,but no significant differences were shown as compared to the solvent control.Arsenious acid(6.25,12.5 and 25.0 μmol/L) could significantly increase DNA Olive tail moment in HepG2 cells(P<0.01 or P<0.05) as compared to the solvent control in a dose-dependent manner.Compared with the DNA damage caused by arsenious acid(12.5 μmol/L) exposure alone,DNA Olive tail moment in HepG2 cells was significantly decreased after co-exposure to 2.5 μmol/L of sodium selenite and 12.5 μmol/L of arsenious acid(P<0.01).Conversely DNA Olive tail moment was significantly increased after co-exposure to 5.0 μmol/L of sodium selenite and 25.0 μmol/L of arsenious acid (P<0.05).Conclusion The effect of sodium selenite on arsenious acid-induced DNA damage in HepG2 cells was associated with the concentrations of arsenious acid and sodium selenite.