Hypomethylation of dual specificity phosphatase 22 promoter correlates with duration of service in firefighters and is inducible by low-dose benzo[a]pyrene

J Occup Environ Med. 2012 Jul;54(7):774-80. doi: 10.1097/JOM.0b013e31825296bc.


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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Benzo(a)pyrene / analysis
  • Benzo(a)pyrene / toxicity*
  • Cells, Cultured
  • DNA / blood
  • DNA Methylation / drug effects*
  • Dual-Specificity Phosphatases / genetics*
  • Female
  • Firefighters*
  • Gene Expression Regulation / drug effects
  • Humans
  • Male
  • Middle Aged
  • Mitogen-Activated Protein Kinase Phosphatases / genetics*
  • Occupational Exposure
  • Promoter Regions, Genetic*
  • Prostate / drug effects
  • Smoke


  • Smoke
  • Benzo(a)pyrene
  • DNA
  • Mitogen-Activated Protein Kinase Phosphatases
  • DUSP22 protein, human
  • Dual-Specificity Phosphatases