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目的研究热休克蛋白70(HSP70)的表达在二氢二醇环氧苯并(a)芘(BPDE)致DNA损伤中的作用。方法培养人肺腺癌A549细胞,作如下处理BPDE染毒组以不同剂量BPDE(0、2、4、8μmol/L)染毒2h;预热+BPDE染毒组细胞预热(42℃2h,37℃恢复1h)后,再按BPDE染毒组同样处理,各组均设溶剂对照。采用单细胞凝胶电泳技术和Western blot法分别检测DNA的损伤情况与HSP70的表达。结果(1)DNA损伤情况BPDE染毒组DNA损伤程度随BPDE染毒剂量增加而加强,明显高于溶剂对照,差异有统计学意义(P<0.01),组间相互比较,差异亦有统计学意义(P<0.01),且DNA损伤程度与BPDE染毒剂量呈正相关(r=0.96,P<0.05);预热+BPDE染毒组DNA损伤程度随BPDE染毒浓度递增,与预热溶剂对照相比,差异有统计学意义(P<0.01),但在4、8μmol/L的BPDE组间,DNA损伤程度的差异无统计学意义(P>0.05),与BPDE染毒组比较,各剂量下DNA损伤程度均明显增加。(2)HSP70表达情况BPDE染毒组在2、4μmol/L的BPDE作用时HSP70表达逐渐升高,与溶剂对照相比,差异有统计学意义(P<0.05),但在8μmol/L剂量时,表达下调,与溶剂对照组相比,差异无统计学意义(P>0.05);预热+BPDE染毒组HSP70的表达均比预热溶剂对照明增加,在4μmol/L的BPDE作用时HSP70表达水平最高,与2、8μmol/L剂量组相比,差异有统计学意义(P<0.05)。与BPDE染毒组相比,各剂量下HSP70的表达水平均明显增加,差异均有统计学意义(P<0.01)。结论HSP70对BPDE所致A549细胞DNA损伤的保护作用并不明显。
Objective To investigate the role of heat shock protein 70 (HSP70) in the DNA damage induced by dihydric glycol epoxidized benzo (a) pyrene (BPDE). Methods Human lung adenocarcinoma A549 cells were cultured and treated with BPDE (0, 2, 4 and 8μmol / L) for 2h. Preheated + BPDE exposed cells were pre-heated at 42 ℃ for 2h, 37 ℃ recovery 1h), then press the same treatment of BPDE exposure group, each group were solvent control. The damage of DNA and the expression of HSP70 were detected by single cell gel electrophoresis and Western blot respectively. Results (1) DNA damage The DNA damage degree in BPDE-treated group was enhanced with the increase of BPDE dose, which was significantly higher than that in solvent control group (P <0.01). The difference was statistically significant (P <0.01). The degree of DNA damage was positively correlated with the dosage of BPDE (r = 0.96, P <0.05). The DNA damage degree increased with the increase of BPDE concentration in preheating + (P <0.01). However, there was no significant difference in DNA damage between 4 and 8 μmol / L BPDE groups (P> 0.05). Compared with BPDE group, Under the DNA damage were significantly increased. (2) The expression of HSP70 HSP70 expression in BPDE-treated rats exposed to 2,4μmol / L BPDE increased gradually compared with the solvent control (P <0.05), but at the dose of 8μmol / L (P> 0.05). Compared with the solvent control group, the expression of HSP70 in the preheated + BPDE group was higher than that in the preheated solvent group, and the HSP70 group treated with 4 μmol / L BPDE had no significant difference The expression level was the highest, compared with 2, 8μmol / L dose group, the difference was statistically significant (P <0.05). Compared with BPDE group, the expression level of HSP70 in each dose group was significantly increased, the differences were statistically significant (P <0.01). Conclusion The protective effect of HSP70 on DNA damage of A549 cells induced by BPDE is not obvious.