Hypomethylation of dual specificity phosphatase 22 promoter correlates with duration of service in firefighters and is inducible by low-dose benzo[a]pyrene.
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.
Division of Environmental Genetics and Molecular Toxicology, Department of Environmental Health, Center for Environmental Genetics, University of Cincinnati Cancer Institute, College of Medicine, University of Cincinnati, Cincinnati, OH, USA.
Bin
B
Ouyang
C Stuart
CS
Baxter
Hung-Ming
HM
Lam
Samrat
S
Yeramaneni
Linda
L
Levin
Erin
E
Haynes
Shuk-Mei
SM
Ho
D000328:Adult; D001564:Benzo(a)pyrene / Q000032:analysis / Q000633:toxicity*; D002478:Cells, Cultured; D004247:DNA / Q000097:blood; D019175:DNA Methylation / Q000187:drug effects*; D054637:Dual-Specificity Phosphatases / Q000235:genetics*; D005260:Female; D061388:Firefighters; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D054639:Mitogen-Activated Protein Kinase Phosphatases / Q000235:genetics*; D016273:Occupational Exposure; D011401:Promoter Regions, Genetic; D011467:Prostate / Q000187:drug effects; D012906:Smoke
D012906:Smoke; D001564:Benzo(a)pyrene; D004247:DNA; D054639:Mitogen-Activated Protein Kinase Phosphatases; C442824:DUSP22 protein, human; D054637:Dual-Specificity Phosphatases