Aberrant Promoter Methylation of p16INK4a and O6-Methylguanine-DNA Methyltransferase Genes in Workers at a Chinese Uranium Mine

To find the possible association of gene methylation of p16INK4a and O6-Methylguanine-DNA Methyltransferase (O6-MGMT) with occupational exposure to radon, 91 male miners from a uranium mine in China were divided into 4 groups according to the cumulative doses of radon exposure from 2 to 425 WLM (working-level months), and aberrant promoter methylation of p16INK4a and O6-MGMT genes in sputum samples was determined by a specific PCR assay. The results revealed that the methylated rates of 16INK4a gene (z=2.844, P=0.005) and O6-MGMT gene (z=3.034, P=0.002), and the total methylated rate of these two genes (z=3.859, P=0.0001) increased significantly with the cumulative doses of radon among the miners. This methylation could be applied as a potential marker for the detection of early DNA damage induced by occupational radon exposure.