G6PD缺陷对1,4-苯醌致K562细胞DNA甲基化的影响及其机制  

Effect from 1,4-benzoquinone exposure on DNA methylation in G6PD deficient K562 cells

作　　者：章梦莹 王博深 张虹 浦跃朴 尹立红 张娟 ZHANG Mengying;WANG Boshen;ZHANG Hong;PU Yuepu;YIN Lihong;ZHANG Juan(Key Laboratory of Environmental Medicine Engineering,Ministy ofEducation,School of Public Health,Southeast University,Nanjing 210009,Jiangsu,China)

机构地区：[1]东南大学公共卫生学院环境医学工程教育部重点实验室

出　　处：《癌变．畸变．突变》2019年第3期186-192,共7页Carcinogenesis,Teratogenesis & Mutagenesis

基　　金：国家自然科学基金项目(81573120)

摘　　要：目的:研究G6PD缺陷对1,4-苯醌(1,4-BQ)致K562细胞DNA甲基化的影响及其机制。方法:分别采用10和20 μmol/L的1,4-BQ溶液对G6PD缺陷K562细胞和正常表达细胞进行染毒,以未染毒组为对照,各组均设置12、24、48 h共3个染毒时间,另在20 μmol/L 1,4-BQ染毒组细胞中加入1.5 mmol/L谷胱甘肽(GSH)进行干预。采用比色法检测全基因组DNA甲基化相对水平,qPCR法检测甲基转移酶DNMT1、DNMT3a、DNMT3b mRNA表达水平,Western blot法检测DNMT1、DNMT3a蛋白表达水平。结果:10和20 μmol/L 1,4-BQ染毒后的K562细胞全基因组DNA甲基化水平升高(P<0.05),除20 μmol/L 1,4-BQ染毒48 h组外,其他各染毒组的G6PD缺陷K562细胞全基因组DNA甲基化水平均高于正常细胞(P<0.05)。在1,4-BQ染毒后,G6PD缺陷细胞的DNMT1、DNMT3a、DNMT3b mRNA水平以及DNMT1、DNMT3a蛋白表达水平均高于正常细胞(P<0.05)。加入GSH后,G6PD缺陷细胞和正常细胞的全基因组DNA甲基化相对水平、DNMTs mRNA 及蛋白表达水平的差异的无统计学意义(P 均>0.05)。结论:G6PD缺陷可能以抑制K562细胞GSH合成的方式增加氧化应激水平,最终导致细胞DNMTs生成的增多以及全基因组DNA甲基化程度的升高。OBJECTIVE: To investigate the effect of 1,4- benzoquinone (1,4- BQ) exposure and G6PD deficiency on DNA methylation in K562 cells. METHODS:G6PD-deficient K562 cells and normal cells were treated with 0,10,20 μmol/L 1,4-BQ solution for 12,24 and 48 hours. Relative levels of DNA methylation in cell genome were detected by colorimetric analysis and expression levels of DNMT1,DNMT3a and DNMT3b were detected by real-time fluorescence quantitative PCR (qPCR). Expression levels of DNMT1 and DNMT3a proteins were detected by Western blot.RESULTS:The genomic DNA methylation levels in the normal K562 cells were increased in the 10 and 20 μmol/L dose groups (P<0.05) but not by the 20 μmol/L dose group at 24 hour. The methylation levels in the GPPD-deficient K562 cells were significantly higher than that in normal cells for all exposed groups (P<0.05). After 1,4-BQ exposure, the expression levels of DNMT1, DNMT3a, DNMT3b mRNA and DNMT1, DNMT3a proteins in G6PD-deficient cells were higher than those in normal cells (P<0.05). After the addition of GSH, the relative levels of whole genome DNA methylation, DNMTs mRNA and protein expression levels of G6PD - deficient cells and normal cells became non - statistically significant. CONCLUSION:G6PD deficiency might have increased the level of oxidative stress by inhibiting GSH synthesis,which ultimately led to an increase in the production of DNMTs and an increase in the DNAmethylation level of the whole genome.

关 键 词：1 4-苯醌 甲基化 DNA甲基转移酶 谷胱甘肽 

分 类 号：R135.1[医药卫生—劳动卫生]