Methylation Analysis On P14, P15and P16Gene In CpG Island From The Peripheral Blood Cells Of Coke Oven Workers

Objective:To study the association of occupational exposure to polycyclic aromatic hydrocarbons (PAHs) with DNA damage and peripheral blood cells p14, p15and p16gene methylation in promoter CpG islands,and find the sensitive indices for lung cancer’early warning and screening in coke oven workers.Methods:Subjects were consisting of74male employed coke oven workers as the exposed group and47control workers employed in a water-supply plant. Subjects were surveyed by questionnaire to collect the general information such as age. smoking, alcohol consumption and occupation history and history of diseases and so on. Concentrations of airborne benzo[a]pyrene (B[a]P) in working places and subjects’ post-shift urinary1-hydroxypyrene (1-OH-Py) were determined using high-performance liquid chromatography (HPLC). The elbow vein blood was drawn in the morning fasting and divided equivalently into two tubes, one part of blood was separated the peripheral blood mononuclear cells and then immediately detected the DNA damage by single cell gel electrophoresis (SCGE) methods.and another was extracted the genomic DNA and detected p14. p15and p16gene promoter region CpG island methylation by the method of methylation specific polymerase chain reaction (MS-PCR. MSP) technique. Statistical analysis was used to analyze the association of B[a]P exposure level with DNA damage and the incidence of p14,p15and p16methylation.Results:B[a]P’s concentration in the exposed groups’working place was significantly higher than the control group, and urinary1-OH-Py level in the exposed group [(0.46±0.12) μmol/mol Cr] and DNA olive tail moment (OTM)[(0.41±0.25) μm] were significantly increased compared to the controls [(0.17±0.06) μmol/mol Cr,(0.32±0.12)μm](P<0.05). the detection rate of p14.p15and p16gene promoter methylation were significantly higher than the control group (P<0.05); Further analysis found that, with the years of coke operation service increasing, the exposed groups’ p14gene methylation detection rate increased significantly (P<0.05), while no significant difference were observed in p15and p16gene methylation detection rates (P>0.05); and with the elecation of urinary1-OH-Py level, p14and p16gene methylation detection rates significantly increased (P<0.05), while no statistical difference in p15gene methylation (P>0.05).Conclusion:Peripheral blood cells’ p14and p16gene5’-CpG island methylation can be a useful early screening and warning indices for lung cancer in coke oven workers.