Association of the Variant Alleles of the X-Ray Cross Complementing Gene (XRCC1) Gene with Levels of DNA Adduct in Iraqi Workers

Abstract

Background. Today, the world is witnessing a significant increase in the number of vehicles which have been carcinogenic emissions of PAHs, The carcinogenic pathway of PAHs. The inter-individuals differences in xenobiotics metabolizing enzymes and DNA repair capacities (XRCC1 gene) that may reduced or increase the effects of the exposure to these carcinogenic compounds. Objectives. Assessment of a single nucleotide polymorphism of the XRCC1 (codon Arg399Gln) gene and its association with levels of benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA adduct in sera of car repairers and control group.Subjects and Methods. The current study included (60) participants, (20) of the iraqi car repairers, (20) sellers of spare part, and (20) healthy (controll), with the same age range. benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA (BPDE-DNA) adduct was determined by using ELISA technique. Alleles frequency of singl nucleotide polymorphisms of XRCC1 gene was determined by Restriction fragment length polymorphisms (PCR-RFLP). Results  The results of current study indicated that there is a highly significant increase of BPDE-DNA adduct level (p= 0.0001) in the repairers group compared to the groups of spare part sellers and control together. The genotype frequencies studies of XRCC1 gene of car repairers group and controls. The effect of rs25487 genotypes on exposure to PAHs include higher levels of PAHs and PAH-DNA adduct in TT genotype followed by CT genotype and CC showed lower levels.Conclusions As results of prolonged exposure to the higher levels of PAHs that Iraqi car repaiers suffer from, they have highe levels PAH-DNA adduct. especially those who have the TT genotypes, as results of the inefficiency of thier DNA repair system. Compared to the other genotypes.