Altered methylation in tandem repeat element and elemental component levels in inhalable air particles

Area of Science:

• Environmental Health
• Molecular Epidemiology
• Toxicology

Background:

• Particulate matter (PM) exposure is linked to lung cancer, but molecular mechanisms are unclear.
• Elemental components of PM are suspected drivers of toxicity.
• DNA methylation is a potential biomarker for environmental exposures and lung cancer risk.

Purpose of the Study:

• To investigate the association between specific PM elemental components and DNA methylation of tandem repeats.
• To evaluate these associations in a highly exposed population in Beijing, China.

Main Methods:

• The Beijing Truck Driver Air Pollution Study included 60 truck drivers and 60 office workers.
• Blood DNA methylation of SATα, NBL2, and D4Z4 was measured.
• Personal exposure to eight PM2.5 elemental components (Al, Si, S, K, Ca, Ti, Fe, Zn) was assessed.
• Generalized estimating equations (GEE) were used to model associations, adjusting for covariates.

Main Results:

• NBL2 methylation positively correlated with silicon (Si) and calcium (Ca) in truck drivers.
• SATα methylation positively correlated with sulfur (S) in office workers.
• Associations were adjusted for PM2.5 mass and other factors.

Conclusions:

• PM elemental components are associated with specific blood DNA methylation patterns.
• These methylation changes may serve as biomarkers for biological effects of PM exposure.
• Identifying such biomarkers could help detect individuals at higher risk for lung cancer.