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目的 通过异烟肼损伤HL-7702肝细胞,探索谷胱甘肽S转移酶P1(GSTP1)启动子区CpG岛甲基化与损伤的关系.方法 将细胞分为对照组与不同浓度异烟肼(200、400和800 mg/L)处理组,采用比色法检测HL-7702细胞外乳酸脱氢酶(LDH)活性水平;采用实时荧光定量PCR分别检测各组3种DNA甲基转移酶(DNMT)DNMT1、DNMT3a、DNMT3b和GSTP1的mRNA表达;采用酶联免疫法(ELISA)检测3种DNA甲基转移酶蛋白表达;采用亚硫酸盐修饰后测序法(BSP)检测GSTP1启动子区CpG岛的甲基化水平.结果 异烟肼处理细胞上清液中LDH活性水平升高,细胞损伤程度随异烟肼浓度升高而加剧.与对照组比较,400和800 mg/L异烟肼组GSTP1 mRNA表达随异烟肼浓度增加而显著升高(P<0.05,P<0.01),异烟肼高剂量组GSTP1启动子区CpG岛甲基化较对照组降低.3种DNMT蛋白表达水平随异烟肼浓度增加表达升高,高剂量异烟肼组的3种DNA甲基转移酶mRNA和蛋白表达较对照组均显著性增强(P<0.01).结论 异烟肼损伤的肝细胞HL-7702的GSTP1启动子区CpG岛呈低甲基化.“,”Objective To investigate the relationship between methylation of CpG island in glutathione S-transferase P1(GSTP1) promoter region and injury induced by isoniazid in HL-7702 cells.Methods HL-7702 cells were divided into the control group and three isoniazid groups(200,400,800 mg/L).Colorimetric method was used to detect the activity level of lactate dehydrogenase in the medium of HL-7702 cells;the mRNA expression of GSTP1,DNA methyltransferases 1(DNMT1),DNMT3a and DNMT3b were de?tected by real-time fluorescence quantitative PCR;the protein expression levels of DNMT1,DNMT3a and DNMT3b were detected by enzyme-linked immunosorbent assay;the methylation of the CpG island in the GSTP1 promoter region was determined by the bisulfite sequencing PCR.Results The activity level of lactate dehydrogenase in supernatants of the HL-7702 cells in isoniazid group(400, 800 mg/L)was higher than that in the control group(P<0.01).Compared with the control group,the mRNA expression of DNMT 1、3a、3b and GSTP1 were elevated in 400 and 800 mg/L isoniazid groups(P<0.05,P<0.01).The proteins expression of DNMT1 and 3a in the 400 and 800 mg/L isoniazid groups were higher than that in the control group(P<0.05,P<0.01),and the protein expression of DNMT 3b in the 800 mg/L isoniazid groups were higher than that in the control group(P<0.01).The methylation level of CpG is?land in GSTP1 promoter region of three isoniazid groups were decreased.Conclusion The CpG island in the promoter of GSTP1 has hypomethylation in hepatocyte cells damaged by isoniazid.