Polymorphisms of DNA repair genes and risk of non-small cell lung cancer

Lung cancer is a leading cause of cancer mortality with an inter-individual difference in susceptibility to the disease. The inheritance of low-efficiency genotypes involved in DNA repair and replication may contribute to the difference in susceptibility. We investigated 44 single nucleotide polymorphisms (SNPs) in 20 DNA repair genes including nucleotide excision repair (NER) genes XPA, ERCC1, ERCC2/XPD, ERCC4/XPF and ERCC5/XPG; base excision repair (BER) genes APE1/APEX, OGG1, MPG, XRCC1, PCNA, POLB, POL iota, LIG3 and EXO1; double-strand break repair (DSB-R) genes XRCC2, XRCC3, XRCC9, NBS1 and ATR; and direct damage reversal (DR) gene MGMT/AGT. The study included 343 non-small cell lung cancer (NSCLC) cases and 413 controls from Norwegian general population. Our results indicate that SNPs in the NER genes ERCC1 (Asn118Asn, 15310G > C, 8902G > T), XPA (-4G > A), ERCC2/XPD (Lys751Gln) and ERCC5/XPD (His46His); the BER genes APE1/APEX (Ile64Val), OGG1 (Ser326Cys), PCNA (1876A > G) and XRCC1 (Arg194Trp, Arg280His, Arg399Gln); and the DSB-R genes ATR (Thr211Met), NBS1 (Glu185Gln), XRCC2 (Arg188His) and XRCC9 (Thr297Ile) modulate NSCLC risk. The level of polycyclic aromatic hydrocarbon-DNA (PAH-DNA) adducts in normal lung tissue from 211 patients was analysed. The variant alleles of XRCC1(Arg280His), XRCC1 (Arg399Gln), ERCC1(G8092T), ERCC5(His46His) and MGMT/AGT(Lys178Arg) were more frequent in patients with PAH-DNA adduct levels lower than the mean whereas the XRCC1(Arg194Trp) variant was more frequent in cases with higher adduct levels than the mean.