Promoter hypermethylation of the O-methylguanine-DNA methyltransferase (MGMT) DNA repair gene is important during carcinogenesis. We explored whether organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), were associated with hypermethylation of the MGMT gene promoter in peripheral leukocytes among 368 Koreans without cancer. Hypermethylation decreased as OCPs increased (Ptrend=0.02), while PCB concentrations showed an inverted U-shaped association (Pquadratic<0.01). The prevalence of MGMT promoter hypermethylation was highest within the 2nd quintile of the PCB summary score (28.4%), while it was only 2.7% in the upper 10% score. Chronic exposure to these chemicals may affect methylation of the MGMT promoter, with possibly non-monotonic dose response relationships.
Bibliographical noteFunding Information:
This work was partly supported by grants from the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HI13C0715) and the National Research Foundation of Korea (No. 2013R1A2A2A01068254).
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- Organochlorine pesticides
- Persistent organic pollutants
- Polychlorinated biphenyls