An in vitro method to survey DNA methylation in peripheral blood mononuclear cells (PBMCs) treated by airborne particulate matter (PM(10))

The International Agency for Research on Cancer (IARC) has defined outdoor air pollution and PM as the human carcinogen (Group 1), which mainly cause an increased risk of lung cancer. Scientists have considered epigenetic modifications as a possible mechanism to deal with adverse effects of air pollution. This study aimed to compare the effect of airborne PM(10) (PM with aerodynamic diameter ≤10 μm) on in vitro global methylation in human peripheral blood mononuclear cells (PBMCs). PM(10) was sampled in metropolitan Tehran, the capital of Iran. PBMCs were extracted from whole blood of healthy males and treated with PM(10) suspension at concentrations of 50–300 μg/mL for 4 h. Untreated cells were used as the negative control. Genomic DNA was extracted from each sample using the DNA blood mini kit according to the manufacturer’s instruction. Moreover, 5-methylsytosine (%5-mC) and 5-hydroxymethylcytosine (%5-hmC) were measured by the enzyme-linked immunosorbent assay (ELISA) method. %5-mC and %5-hmC in each sample was compared with negative control and reported as difference %5-mC and %5-hmC.