Association Between ERCC2 Gene 751 Point Polymorphisms And Chromosomal Damage Susceptibility In Peripheral Blood Lymphocytes Among Coke Oven Workers

Objective To study the relationship between the polymorphism of the nucleotide excision repair gene ERCC2-751site and the genetic susceptibility of the peripheral lymphocytes in the coke oven workers,so as to ascertain the feasibility of E gene polymorphism being the marker for Susceptibility to polycyclic aromatic hydrocarbon induced genetic damages.Methods The gene polymorphisms among 149 coke oven workers and 29 unexposed occupationall carcinogenic substances controls were determined by PCR-PFLP methods, Chromosomal damage was detected by micronucleus assay and comet assay,Results:The frequency of the A allele and C allele at ERCC2-751 site was 80.26%,19.74%and 79.31%,20.69%for the exposed group and the control group respectively,without significant difference between the two groups by statistical testing(P＞0.05).The distribution frequency of A/A,A/C,C/C genotypes at the exposed group and the control group ERCC2-751 site was 67.1%, 26.3%,6.6%和65.5%,27.6%,6.9%respectively,also without significant difference between the two groups(P＞0.05).All the gene distributions matched the equilibrium law of Hardy-Weinberg.No obvious difference influence was found in gene distributions among workers,regardless of their smoking habit,drinking habit,age,or duration of exposure(P＞0.05).The micronucleus rate of coke oven worker was 1.03±0.91,and the tail moment(TM)was 2.63±0.95;the micronucleus rate of control group was 1.00±0.87,and the tail moment was 1.94±0.66,TM noticeably higher in the exposed group(P＜0.01).The micronucleus rate of ERCC2-751 A/A,C/C,A/C,C/C+A/C genotypes in exposed group was 0.93±0.87,1.31±0.91,1.25±0.98 and 1.26±0.97,,workers with A/C genotype or C/C+A/C genotype were found to have higher micronucleus rate that those with A/A genotype in the exposed group(P＜0.05).The micronucleus rate of ERCC2-751 A/A,C/C,A/C,C/C+A/C genotypes in control group was 0.94±0.99,1.20±0.30,1.09±0.76和1.11±0.68,respectively,those carrying mutant C gene had higher rate than wild-type A/A gene,but without significant statistical differences between them(P＞0.05).In the exposed group,Among the smokers,the micronucleus rate was 1.43±0.98,1.45±0.98 for those with ERCC2-751 A/C,C/C+A/C genotype,respectively, significant higher than those with A/A genotype.The same result was also observed among the non-drinkers and non-drinkings.And for workers who had been exposed to coke oven for more than 11 years,those with A/C和C/C+A/C had higher micronucleus rate(1.664±1.01 and 1.70±0.97)than those with A/A genotype(1.04±0.93,P＜0.05).The TM were 2.76±0.92,2.26±0.89,2.55±0.97, 2.49±0.96 and 1.89±0.74,1.94±0.31,2.05±0.53,2.03±0.48 among exposed group and control group with ERCC2-751 A/A,C/C,A/C,C/C+A/C genetypes,There were no sifnificant differences among genetypes(P＞0.05).Conclusion:We had not observed influence between coke oven dissipation and distribution of ERCC2-751 gene and genetype.Those carrying at least one mutational C allele had higher rate than those with AA allele,may be the risk factor of chromosome damage of coke oven workers. Polymorphism of ERCC2-751 related to polycyclic aromatic hydrocarbon induced genetic damages, may serve as the marker for susceptibility to polycyclic aromatic hydrocarbon induced genetic damages.