Association of Polymorphisms in AhR, CYP1A1, GSTM1, and GSTT1 Genes with Levels of DNA Damage in Peripheral Blood Lymphocytes among Coke-Oven Workers

Abstract

Accumulating evidence has shown that both DNA damage caused by the metabolites of polycyclic aromatic hydrocarbons (PAH) and genetic polymorphisms in PAH-metabolic genes contribute to individual susceptibility to PAH-induced carcinogenesis. However, the functional relevance of genetic polymorphisms in PAH-metabolic genes in exposed individuals is still unclear. In this study of 240 coke-oven workers (the exposed group) and 123 non–coke-oven workers (the control group), we genotyped for polymorphisms in the AhR, CYP1A1, GSTM1, and GSTT1 genes by PCR methods, and determined the levels of DNA damage in peripheral blood lymphocytes using the alkaline comet assay. We found that the ln-transformed Olive tail moment (Olive TM) values in the exposed group were significantly higher than those in the control group (P < 0.001). Furthermore, in the exposed group, the Olive TM values in subjects with the AhR Lys⁵⁵⁴ variant genotype were higher than those with the AhR Arg⁵⁵⁴/Arg⁵⁵⁴ genotype (P = 0.021). Similarly, the Olive TM values in the non–coke-oven workers with the CYP1A1 MspI CC + CT genotype were lower than the values of those with the CYP1A1 MspI TT genotype (P = 0.005). However, these differences were not evident for GSTM1 and GSTT1. These results suggested that the polymorphism of AhR might modulate the effects of PAHs in the exposed group; however, the underlying molecular mechanisms by which this polymorphism may have affected the levels of PAH-induced DNA damage warrant further investigation. (Cancer Epidemiol Biomarkers Prev 2006;15(9):1703–7)