氢醌作用下L-02人肝细胞中聚合酶η的表达及其与DNA损伤耐受的关系  

Relationship between Polymerase eta expression and DNA damage-tolerance in human hepatic cells by hydroquinone

作　　者：胡恭华[1] 庄志雄[2] 黄海燕[2] 庾蕾[2] 杨淋清[2] 纪卫东[3] 

机构地区：[1]赣南医学院预防医学系,赣州341000 [2]深圳市疾病预防控制中心毒理研究室 [3]中山大学公共卫生学院

出　　处：《中华预防医学杂志》2009年第1期56-60,共5页Chinese Journal of Preventive Medicine

基　　金：基金项目：国家重点基础研究发展计划（2002CB512903,2002CB512904）

摘　　要：目的研究氢醌（hydroquinone，HQ）对L-02人肝细胞中跨损伤合成DNA聚合酶11（Pokq）表达及DNA损伤的影响，探讨Polη在DNA损伤耐受过程中的作用及其可能机制。方法将L-02人肝细胞用不同浓度（0、5、10、20、40、80和160μmoL／L）的HQ作用24h之后，采用噻唑蓝（MTT）比色法测定细胞相对存活率；单细胞凝胶电泳检测DNA损伤情况；实时荧光定量PCR和Westernblotting技术检测Pohη在mRNA和蛋白质水平上的表达。结果在0～80μmol／L的范围内，HQ对L-02人肝细胞的存活率没有明显的影响；当染毒剂量超过160μmol/L时，其存活率则降为（79．20．±7．94）％，与对照组（100．00±3．71）％比较，差异有统计学意义（F=17．11，P〈0．01）。随着HQ作用浓度的升高，L-02人肝细胞DNA链的断裂程度也随着逐渐增加。在HQ染毒剂量0～80μmol／L的范围内，Polη在mRNA水平（相对定量值依次为1．00±0．00、1．20±0．09、2．02±0．19、2．37±0．10、2．67±0．16和4．40±0．18）和蛋白质水平（相对定量值依次为0．22、0．24、0．34、0．44、0．45和1．25）上的表达均有随着剂量的增加而增加的趋势，80txmoL／L处达到峰值；当HQ的剂量达到160μmol／L时，Polrη的表达则有所降低，mRNA水平和蛋白质水平相对定量值分别为2．32±0．16和1．20，高于对照组。结论Pobη可能参与了HQ所致L-02人肝细胞DNA损伤的耐受过程。Objective To investigate the effects of hydroquinone（HQ） on expression of Polymerase eta （Polη） and DNA damage in human hepatic cells （L-02）, and to explore the role and possible mechanism of Polnη involved in the process of DNA damage-tolerance. Methods After L-02 hepatic cells were exposed to HQ with various concentrations （0,5,10,20,40,80 and 160 μmol/L） for 24 h, cell survival rate was detected by MTT assay; DNA impairment was detected by single cell gel electrophoresis（SCGE） ; Real-time fluorescent quantitative PCR and Western blotting methods were used to measure the expression of Pol-η at the mRNA and protein level in L-02 hepatic cells exposed to HQ with various concentrations（0,5,10,20, 40,80 and 160 p^mol/L）. Results MTT assay showed that HQ with concentrations from 0 to 80 p.mol/L had little effect on the survival rate of L-02 （P 〉 O. 05 ）; whereas the survival rate of the group of 160 μmol/Lwas significantly higher than that of the control（ P 〈 0.01 ） after being treated with HQ for 24 h ; the higher dose of HQ presented, the more degrees of DNA damage were produced. It was found that HQ in a low concentration （1-80 μmol/L） could induce the expression of Polη which was in proprotion to the inereasement of HQ concentration ; the expression levels of mRNA and protein were reached to the maximum when treated with 80 μmol/L; the expression of Pol-ηdecreased （ the relative quantity values were 2. 32 ± 0. 16 and 1.20 respectively） once the concentration of HQ exceeded 160 μmol/L as compared with the group of 80 μmol/L, but it was higher than that of the control. Conclusion This study suggested that Polη might involve in the process of DNA damage-tolerance induced by HQ in the hepatic cells.

关 键 词：氢醌类 肝细胞 DNA损伤 

分 类 号：R686[医药卫生—骨科学]