X线修复交叉互补基因1对氢醌致人支气管上皮细胞DNA损伤的保护作用(英文)

X-ray repair cross complementing group 1 protects human bronchial epithelial cells from hydroquinone-induced DNA damage

目的探索氢醌对人支气管上皮细胞遗传毒性的分子机制,并研究X线修复交叉互补基因1(XRCC1)对氢醌致人支气管上皮细胞DNA损伤是否有保护作用。方法通过RNA干扰敲除XRCC1基因,通过转染重组质粒pEGFP-C1-pU6-dsRNA建立XRCC1缺陷细胞;正常人支气管上皮细胞和转染空载体pEGFP-C1的细胞分别作为正常对照组和载体对照组;3种细胞用不同浓度(10 ～100 μmol.L-1)的氢醌作用4 h,分别进行MTT实验和彗星实验来检测氢醌的毒性。结果 MTT结果显示,不同浓度(10 ～100μmol.L-1)氢醌作用的XRCC1缺陷细胞,490 nm波长处吸光度值低于对照组细胞,提示缺陷细胞的细胞存活率比正常细胞低;彗星实验结果显示,不同浓度的氢醌对XRCC1缺陷细胞DNA损伤比对照组细胞更严重,而2个对照组细胞之间没有明显差异。结论 XRCC1基因在氢醌导致的细胞损伤的修复方面起着重要的作用。

AIM To explore the molecular mechanism of hydroquinone genotoxicity in human bronchial epithelial cells and investigate whether human X-ray repair cross complementing group 1（XRCC1）was involved in protecting cells from the damage caused by hydroquinone.METHODS XRCC1 gene was knocked down by RNA interference and XRCC1-deficient cell was established by transfected recombinant plasmid pEGFP-C1-pU6-dsRNA.Normal human bronchial epithelial cells（normal cells） and cells transfected with the empty vector of pEGFP-C1（vector cells） were used as the normal control and vector control.All cells were treated with different concentrations of hydroquinone（10-100 μmol·L^-1） for 4 h.MTT assay was used to test cell viability and comet assay was used to detect the DNA damage and repairment.RESULTS MTT assay showed that hydroquinone inhibited the growth of cells in a concentration-dependant manner and the survival number of XRCC1-deficient cell was less than that of the two control groups.Comet assay revealed that different concentrations of hydroquinone caused more severe DNA damage in XRCC1-deficient cell line than in control cells and there were no significant difference in the two control groups.CONCLUSION The results suggest XRCC1 be involved in preventing cells from damage caused by hydroquinone.