DNA Methylation And Telomere Damage In Occupational People Exposed To Coal Tar Pitch

ObjectiveTo survey p16, FHIT and RASSF1A gene promoter methylation and telomere damage in the population of occupational exposure to coal tar pitch, and to explore the effective mark of occupational exposure to coal tar pitch.Materials and methods1.180cases of occupational exposure to coal tar pitch were recruited from a Carbon Plant workers in the middle;145cases in the control group were recruited from the crowd of normal physical examination during the same period, the crowd is conducted physical examination in the First Affiliated Hospital of the school. After their informed consent, collectes peripheral blood and gathered basic information by professional investigators.2. The P16RASSF1A and FHIT genes promoter methylation status in peripheral blood DNA were evaluated using SYBR Green-based quantitative ethylation-specific PCR (qMSP). Relative telomere length in peripheral blood genomic DNA was measured by Quantitative PCR.3. Methods of representation and examination were based on the distribution of quantitative data. All statistical tests were two-sided, and the level of statistical significance was set at a=0.05.Results1. The telomere length were0.83(0.71-0.90) and1.13(0.72-1.45) in the group of occupational exposure to coal tar pitch and the group of control respectively, there was statistical difference between two groups (Z=-5.395, P<0.001).2. In the groups of occupational exposure and control, the rates of p16gene promoter methylation were0.56(0.13-4.95) and0.37(0.06-4.23) respectively, there was no statistical difference between two groups (Z=-1.395, P=0.163); the rates of FHIT promoter methylation were3.22(2.09-4.64) and2.95(1.45-5.88) respectively, there was no statistical difference between two groups (Z=-0.906, P=0.365); the rates of RASSF1A gene promoter methylation rates were14.76(7.26-39.09) and19.34(3.82-50.95) respectively, there was no statistical difference between two groups (Z=-0.455, P=0.649).ConclusionOccupational exposure to coal tar pitch may induce leukocyte DNA telomere length of human peripheral blood shortened; Occupational exposure to coal tar pitch can not result in the changes of p16, RASSF1A and FHIT gene promoter methylation rates.