Shen M L, He Z N, Zhang X, Duan H W, Niu Y, Bin P, Ye M, Meng T, Dai Y F, Yu S F, Chen W, Zheng Y X
National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2017 Jun 6;51(6):556-561. doi: 10.3760/cma.j.issn.0253-9624.2017.06.019.
To investigate the association between etheno-DNA adduct and the promoter of DNA methylation levels of cyclin dependent kinase inhibitor 2A (P16), Ras association domain family 1 (RASSF1A) and O-6-methylguanine-DNA methyltransferase (MGMT) in workers with occupational exposure to diesel engine exhaust (DEE). We recruited 124 diesel engine testing workers as DEE exposure group and 112 water pump operator in the same area as control group in Henan province in 2012 using cluster sampling. The demographic data were obtained by questionnaire survey; urine after work and venous blood samples were collected from each subject. The urinary etheno-DNA adducts were detected using UPLC-MS/MS, including 1,N6-etheno-2'-deoxyadenosine (εdA) and 3,N4-etheno-2'-deoxycytidine(εdC). The DNA methylation levels of P16, RASSF1A, and MGMT were evaluated using bisulfite-pyrosequencing assay. The percentage of methylation was expressed as the 5-methylcytosine (5mC) over the sum of cytosines (%5mC). Spearman correlation and multiple linear regression were applied to analyze the association between etheno-DNA adducts and DNA methylation of P16, RASSF1A, and MGMT. The median ((25)-(75)) of urinary εdA level was 230.00 (98.04-470.91) pmol/g creatinine in DEE exposure group, and 102.10 (49.95-194.48) creatinine in control group. The level of εdA was higher in DEE exposure group than control group (0.001). DNA methylation levels of P16, RASSF1A and MGMT were 2.04±0.41, 2.19 (1.94-2.51), 2.22 (1.94-2.46)%5mC in exposure group, and 2.19±0.40, 2.41 (2.11-2.67), 2.44 (2.15-2.91)%5mC in control group. DNA methylation levels were lower in exposure group ( values were 0.005, 0.002 and 0.001, respectively). Spearman correlation analysis showed that DNA methylation levels of P16, RASSF1A, and MGMT were negative associated with urinary εdA level ( values were -0.155, -0.137, and -0.198, respectively, 0.05). No significant correlation was observed between the εdC level and any measured DNA methylation levels (0.05) . Multiple linear regression confirmed the negative correlation between εdA and DNA methylation levels of P16, RASSF1A, and MGMT in non-smoking group (β (95) was -0.068 (-0.132--0.003), -0.082 (-0.159--0.004) and -0.048 (-0.090--0.007), values were 0.039, 0.039 and 0.024, respectively). Moreover, εdC was negative associated with DNA methylation level of MGMT in non-smoking group (β (95) was -0.094 (-0.179--0.008), 0.032). DEE exposure could induce the increased of εdA and decreased of DNA methylation levels of P16, RASSF1A and MGMT.
探讨职业接触柴油机尾气（DEE）工人中乙烯基-DNA加合物与细胞周期蛋白依赖性激酶抑制剂2A（P16）、Ras关联结构域家族1（RASSF1A）和O-6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）启动子DNA甲基化水平之间的关联。2012年，我们采用整群抽样的方法，在河南省招募了124名柴油机测试工人作为DEE暴露组，以及同一地区的112名水泵操作员作为对照组。通过问卷调查获取人口统计学数据；从每个受试者收集工作后的尿液和静脉血样本。使用超高效液相色谱-串联质谱法（UPLC-MS/MS）检测尿中乙烯基-DNA加合物（包括1,N6-乙烯基-2'-脱氧腺苷（εdA）和3,N4-乙烯基-2'-脱氧胞苷（εdC））。采用亚硫酸氢盐焦磷酸测序法评估P16、RASSF1A和MGMT的DNA甲基化水平。甲基化百分比表示为5-甲基胞嘧啶（5mC）占胞嘧啶总和的比例（%5mC）。应用Spearman相关性分析和多元线性回归分析乙烯基-DNA加合物与P16、RASSF1A和MGMT的DNA甲基化之间的关联。DEE暴露组尿εdA水平的中位数（（25）-（75））为230.00（98.04-470.91）pmol/g肌酐，对照组为102.10（49.95-194.48）肌酐。DEE暴露组的εdA水平高于对照组（P<0.
