Objective: Firefighters (FFs) are chronically exposed to smoke and products of incomplete combustion, which frequently contain polycyclic aromatic hydrocarbons (PAHs). This study examined the possibility of an association between PAH-induced epigenetic alterations and occupational firefighting exposure.
Methods: Promoter methylation was analyzed in four genes in blood DNA from 18 FFs and 20 non-FFs (controls). Jurkat and human normal prostate epithelial cells were treated with benzo[a]pyrene to ascertain the epigenetic effects of this type of agent.
Results: Firefighters had a higher prevalence of dual specificity phosphatase 22-promoter hypomethylation in blood DNA (P = 0.03) and the extent of hypomethylation correlated with duration of firefighting service (P = 0.04) but not with age. Benzo[a]pyrene reduced promoter methylation and increased gene expression of the same gene in Jurkat and normal prostate epithelial cells.
Conclusions: Cumulative occupational exposure to combustion-derived PAHs during firefighting can cause epigenetic changes in promoters of specific genes.
From the Division of Environmental Genetics and Molecular Toxicology (Drs Ouyang, Baxter, Lam, and Ho) and Division of Epidemiology and Biostatistics (Mr Yeramaneni, and Drs Levin and Haynes), Department of Environmental Health, Center for Environmental Genetics, University of Cincinnati Cancer Institute, College of Medicine, University of Cincinnati, and Cincinnati Veterans Affairs Medical Center (Dr Ho), Cincinnati, Ohio.
Address correspondence to: Shuk-Mei Ho, PhD, Department of Environmental Health, Kettering Complex, Room 128, 3223 Eden Ave, University of Cincinnati Medical Center, Cincinnati, OH 45267 (firstname.lastname@example.org).
This work is supported in part by National Institutes of Health grants: CA 112532 (SMH), ES015584 (SMH), ES018758 (SMH), ES018789 (SMH), ES015584 (SMH), ES018789 (SMH), ES015905 (SMH), ES019480 (SMH), ES006096 (SMH; ENH), ES016531 (ENH), and ES017362 (ENH).
Shuk-mei Ho and coauthors have no relationships/conditions/circumstances that present potential conflict of interest.
The JOEM Editorial Board and planners have no financial interest related to this research.
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