PM(2.5) exposure and DLEC1 promoter methylation in Taiwan Biobank participants

BACKGROUND: Particulate matter (PM) < 2.5 μm (PM(2.5)) or fine PM is a serious public health concern. It affects DNA methylation and heightens carcinogenesis. Deleted in lung and esophageal cancer 1 (DLEC1) is a tumor suppressor gene. However, aberrant methylation of the gene is associated with several cancers. We evaluated the association between PM(2.5) and DLEC1 promoter methylation in Taiwanese adults based on regular outdoor exercise. METHODS: We obtained DNA methylation and exercise data of 496 participants (aged between 30 and 70 years) from the Taiwan Biobank (TWB) database. We also extracted PM(2.5) data from the Air Quality Monitoring Database (AQMD) and estimated participants’ exposure using residential addresses. RESULTS: DLEC1 methylation and PM(2.5) were positively associated: beta coefficient (β) = 0.114 × 10(−3); p value = 0.046. The test for interaction between exercise and PM(2.5) on DLEC1 methylation was significant (p value = 0.036). After stratification by exercise habits, PM(2.5) and DLEC1 methylation remained significantly associated only among those who exercised regularly (β = 0.237 × 10(−3); p value = 0.007). PM(2.5) quartile-stratified analyses revealed an inverse association between regular exercise and DLEC1 methylation at PM(2.5) < 27.37 μg/m(3) (β = − 5.280 × 10(−3); p value = 0.009). After combining exercise habits and PM(2.5) quartiles, one stratum (i.e., regular exercise and PM(2.5) < 27.37 μg/m(3)) was inversely associated with DLEC1 methylation (β = -5.160 × 10(−3), p value = 0.007). CONCLUSIONS: We found significant positive associations between PM(2.5) and DLEC1 promoter methylation. Regular exercise at PM(2.5) < 27.37 μg/m(3) seemingly regulated DLEC1 promoter methylation.