Association of low-dose exposure to persistent organic pollutants with E-cadherin promoter methylation in healthy Koreans

Background: Persistent organic pollutants (POPs), despite their considerably low levels in humans, are an increasing concern for the general populations given their various adverse health problems, including metabolic and carcinogenic effects. DNA methylation deregulation is thought to be a key mechanism in the development of human chronic diseases including cancer. Methods: In an attempt to identify biomarkers monitoring low-dose exposure and hazard, we explored whether organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) may influence the methylation of tumour suppressor gene E-cadherin (CDH1) using peripheral blood cells from 364 healthy Korean subjects. Results: CDH1 methylation was observed in 78.3% of study subjects. Serum concentrations of OCPs or PCBs compounds were higher in CDH1 methylation-positive subjects than in methylation-negative ones. After adjusting for various covariates, the odds ratio of CDH1 methylation of the summary measure of PCBs were 1.0, 2.5 (95% confidence interval: 1.2–5.3), 3.6 (1.6–8.1), 3.6 (1.4–8.6), and 2.5 (1.1–5.7) across quintiles of PCBs (P_trend = 0.01). The values of OCPs were 1.0, 0.9, 1.2, 2.4 (1.0–5.9), and 1.7 (P_trend = 0.05). Conclusions: In this exploratory study with a small sample, CDH1 methylation might be served as the epigenetic biomarker associated with POPs exposure and adverse health effect.