F2RL3 methylation as a biomarker of current and lifetime smoking exposures

Environ Health Perspect. 2014 Feb;122(2):131-7. doi: 10.1289/ehp.1306937. Epub 2013 Nov 22.


Background: Recent genome-wide DNA methylation studies have found a pronounced difference in methylation of the F2RL3 gene (also known as PAR-4) in blood DNA according to smoking exposure. Knowledge on the variation of F2RL3 methylation by various degrees of smoking exposure is still very sparse.

Objectives: We aimed to assess dose-response relationships of current and lifetime active smoking exposure with F2RL3 methylation.

Methods: In a large population-based study, we quantified blood DNA methylation at F2RL3 for 3,588 participants using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Associations of smoking exposure with methylation intensity were examined by multiple linear regression, controlling for potential confounding factors and paying particular attention to dose-response patterns with respect to current and lifetime smoking exposure as well as time since cessation of smoking.

Results: F2RL3 methylation intensity showed a strong association with smoking status (p < 0.0001), which persisted after controlling for potential confounding factors. Clear inverse dose-response relationships with F2RL3 methylation intensity were seen for both current intensity and lifetime pack-years of smoking. Among former smokers, F2RL3 methylation intensity increased gradually from levels close to those of current smokers for recent quitters to levels close to never smokers for long-term (> 20 years) quitters.

Conclusions: F2RL3 methylation is a promising biomarker for both current and long-term past tobacco exposure, and its predictive value for smoking-related diseases warrants further exploration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers / metabolism*
  • Cohort Studies
  • DNA Methylation*
  • Germany / epidemiology
  • Humans
  • Linear Models
  • Middle Aged
  • Receptors, Thrombin / genetics
  • Receptors, Thrombin / metabolism*
  • Smoking / epidemiology*
  • Smoking / metabolism*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Statistics, Nonparametric


  • Biomarkers
  • Receptors, Thrombin
  • protease-activated receptor 4