Radio-adaptive response, individual radio-sensitivity and correlation of base excision repair gene polymorphism (hOGG1, APE1, XRCC1, and LIGASE1) in human peripheral blood mononuclear cells exposed to gamma radiation.

Radio-adaptive response (RAR) is a biological mechanism, where cells primed with a low dose exhibit reduced DNA damage with a high challenging dose. Single nucleotide polymorphisms (SNPs) of DNA repair genes including base excision repair (BER) pathway are known to be associated with radio-sensitivity but involvement in RAR is not yet understood. In the present study, attempt was made to correlate genotype frequencies of four BER SNPs [hOGG1(Ser326Cys), XRCC1(Arg399Gln), APE1(Asp148Glu) and LIGASE1(A/C)] with DNA damage, repair and mRNA expression level among 20 healthy donors (12 adaptive and 8 nonadaptive). Our results revealed that LIGASE1 (p = .002) showed significant correlation with DNA damage and mRNA expression level with increasing dose. hOGG1 (Ser326Cys), XRCC1 (Arg399Gln) and LIGASE1(A/C) polymorphisms showed significant difference with DNA damage (%T) and mRNA expression profile in primed cells among adaptive donors. In conclusion, BER gene polymorphisms play important role in identifying donors with radio-sensitivity and RAR in human cells.