XPD基因在氢醌致U937细胞DNA损伤修复中的作用

Role of XPD gene in DNA damage repair of U937 cells induced by hydroquinone

目的探讨XPD基因在氢醌(HQ)致U937细胞DNA损伤修复中的作用。方法选择5、10、20、40、80μmol/L HQ分别对U937细胞染毒12、24、48 h,根据各浓度下U937细胞活性,选择10、20、40μmol/L HQ染毒24、48 h进行后续实验。取10、20、40μmol/L HQ染毒24、48 h U937细胞,分别设为HQ低、中、高浓度组,另取未染毒U937细胞作为空白对照组,采用单细胞凝胶电泳检测各组细胞尾矩(TM)、Oliv尾矩(OTM),采用Western blotting法检测各组XPD蛋白相对表达量。结果与空白对照组比较,HQ低、中、高浓度组染毒24、48 h TM和OTM均明显增大(P均<0.05);与同组染毒24 h比较,HQ低、中、高浓度组染毒48 h TM和OTM均明显增大(P均<0.05),染毒48 h HQ低、中、高浓度组TM和OTM依次升高(P均<0.05)。与空白对照组比较,HQ低、中、高浓度组染毒24 h XPD蛋白相对表达量均明显升高(P均<0.05),且HQ高浓度组明显高于HQ低浓度组(P均<0.05);染毒48 h,HQ高浓度组XPD蛋白相对表达量明显高于空白对照组及HQ低、中浓度组(P均<0.05),但空白对照组及HQ低、中浓度组两两比较差异均无统计学意义(P均>0.05);HQ各浓度组染毒48 h XPD蛋白相对表达量与染毒24 h比较差异均无统计学意义(P均>0.05)。结论 XPD基因表达上调可促进HQ致U937细胞DNA损伤修复。

Objective To investigate the role of XPD gene in DNA damage repair of U937 cells induced by hydroquinone（ HQ）. Methods U937 cells were treated with 5,10,20,40,and 80 μmol/L HQ for 12,24 and 48 h. According to the cell activity,we selected 10,20,and 40 μmol/L HQ for the following experiments. U937 cells were treated with10,20 and 40 μmol/L HQ for 24 and 48 h,which were taken as the low-dose,medium-dose,and high-dose HQ groups,meanwhile,the untreated U937 cells were taken as the blank control group. Single cell gel electrophoresis tail moment（ TM） and Oliv tail moment（ OTM） were used to detect DNA damage. The relative expression of XPD protein in each group was determined by Western blotting. Results Compared with the blank control group,TM and OTM in the lowdose,medium-dose,and high-dose HQ groups at 24,48 h significantly increased（ both P〈0. 05）. TM and OTM in the low-dose,medium-dose,and high-dose HQ groups at 48 h significantly increased as compared with that of the same group at 24 h（ both P〈0. 05）,and the TM and OTM values of the low-dose,medium-dose,and high-dose HQ groups increased successively（ both P〈0. 05）. Compared with the blank control group,the relative expression of XPD protein in the lowdose,medium-dose,and high-dose HQ groups at 24 h was significantly higher（ P〈0. 05）,and the high-dose group was significantly higher than the low-dose group（ P〈0. 05）. The relative expression of XPD protein in the high-dose HQ group at 48 h was significantly higher than that in the blank control group,low-dose,and medium-dose HQ groups（ P〈0. 05）,but there was no significant difference between the blank control group and low-dose and medium-dose HQ groups（ all P〈0. 05）. The relative expression of XPD protein in each group at 48 h was not significantly different from that at 24 h（ all P〈0. 05）. Conclusion The up-regulation of XPD gene expression promotes the repair of DNA damage of U937 cells induced by HQ.