Key Laboratory of Chemical Safety and Health, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, P. R. China.
Toxicol Sci. 2011 Nov;124(1):99-108. doi: 10.1093/toxsci/kfr216. Epub 2011 Aug 26.
The purpose of this study was to address the association between the ataxia telangiectasia mutated (ATM) gene polymorphisms and susceptibility to DNA repair capacity (DRC) among polycyclic aromatic hydrocarbons (PAHs)-exposed workers. Polymorphisms of ATM were genotyped. DRC was determined by comet assay. Chromosomal damage was detected by cytokinesis-block micronucleus (CBMN) assay. Flow cytometry was used to detect the distributions of cell cycle. Expressions of ATM and rH2AX were determined by immunoblotting analysis. Luciferase assays were performed to determine the functional difference of ATM promoter region allele. Subjects carrying T allele of rs228589 had significantly lower DRC compared with those with AA genotype. Subjects carrying G allele of rs652311 had significantly lower DRC than those with zero copy number of haplotype CGGT. SH ataxia telangiectasia mutated (SHATM) cells had significantly lower DRC than SH green fluorescent protein (SHGFP) cells induced by bleomycin and higher CBMN frequencies treated by benzo(a)pyrene [B(a)P] than SHGFP cells. After B(a)P treatment, a decrease in the percentage of G1 phase cells was observed in SHATM cells compared with SHGFP cells, rH2AX expressions were increased in SHATM cells and SHGFP cells, but ATM expressions had no change in 16HBE-SHGFP cells and HEK-SHGFP cells. Luciferase expression was not different between rs228589T and rs228589A plasmid constructs. In conclusions, it is suggested that ATM polymorphisms are associated with DRC among PAHs-exposed workers and ATM plays key roles in repair of chromosomal damage and cell cycle control with the treatment of B(a)P.
本研究旨在探讨共济失调毛细血管扩张突变（ATM）基因多态性与多环芳烃（PAHs）暴露工人 DNA 修复能力（DRC）易感性之间的关系。对 ATM 多态性进行基因分型。彗星试验测定 DRC。胞质分裂阻断微核（CBMN）试验检测染色体损伤。流式细胞术检测细胞周期分布。免疫印迹分析检测 ATM 和 rH2AX 的表达。荧光素酶试验检测 ATM 启动子区域等位基因的功能差异。与 AA 基因型相比，携带 rs228589T 等位基因的个体 DRC 显著降低。与 CGGT 单倍型零拷贝数相比，携带 rs652311G 等位基因的个体 DRC 显著降低。与 SH 绿色荧光蛋白（SHGFP）细胞相比，SH 共济失调毛细血管扩张突变（SHATM）细胞经博来霉素诱导的 DRC 显著降低，经苯并（a）芘（B（a）P）处理的 CBMN 频率显著升高。与 SHGFP 细胞相比，B（a）P 处理后 SHATM 细胞 G1 期细胞比例下降，rH2AX 表达增加，但 16HBE-SHGFP 细胞和 HEK-SHGFP 细胞中 ATM 表达无变化。rs228589T 和 rs228589A 质粒构建物的荧光素酶表达无差异。综上所述，提示 ATM 多态性与 PAHs 暴露工人的 DRC 相关，ATM 在 B（a）P 处理时对染色体损伤和细胞周期调控的修复起关键作用。
