These results suggest that the hOGG1Ser326Cys polymorphism plays an important role in the risk for lung cancer and is linked to exposure to tobacco smoke.
This study examines the association between 24 single-nucleotide polymorphisms (SNPs) belonging to five BER genes (XRCC1, APEX1, PARP1, MUTYH and OGG1) and lung cancer among Latinos (113 cases and 299 controls) and African-Americans (255 cases and 280 controls).
Moreover, in subgroup analyses by cancer types, the stronger significant association between hOGG1Ser326Cys polymorphism and lung cancer risk was found (Cys/Cys vs. Ser/Ser: OR = 1.29, 95%CI = 1.16-1.44, P<0.001; Cys/Cys vs. Cys/Ser+Ser/Ser: OR = 1.22, 95%CI = 1.12-1.33, P<0.001).
The authors conclude that there was a noticeable modifying effect on the association between hOGG1 genotype and lung cancer risk by cigarette smoking status.
Case-control studies to date suggest that the OGG1-326Cys allele is associated with a higher risk for several types of cancers, including overall lung cancer.
Despite some limitations, this meta-analysis provides solid evidence that hOGG1Ser326Cys polymorphism may contribute to lung cancer risk, particularly for Asian populations, never smokers, and more-cigarette takers.
In stratified analyses by control source, compared with the Ser/Ser genotype, lung cancer risk associated with the hOGG1 Cys/Cys genotype was significantly increased in population-based studies (OR, 1.32; 95% CI, 1.04-1.67) but not in hospital-based studies (OR, 1.18; 95% CI, 0.98-1.42); in stratified analyses by the smoking status, however, the increased risk was observed only among nonsmokers in a dominant model (OR, 1.32; 95% CI, 1.04-1.67).
OGG1S326C homozygote was suggested to be associated with lung cancer risk in Caucasians (homozygote OR, 1.34; 95% CI, 1.01-1.79) based on 2,569 cases and 4,178 controls from 4 studies but not in Asians.
Using the multifactor dimensionality reduction method, we found a model of gene-gene interactions associated with the risk of lung cancer: NBS1 (rs1805794)-XRCC1 (rs25487)-hOGG1 (rs1052133)-XPG (rs17655).
When all the eligible studies were pooled into the meta-analysis of OGG1Ser326Cys polymorphism, significantly increased lung cancer risk was observed in recessive model (OR = 1.17, 95 % CI = 1.03-1.33) and in additive model (OR = 1.21, 95 % CI = 1.03-1.42).
In a nested case-cohort study, we have investigated the occurrence of lung cancer in relation to polymorphisms in base excision repair genes XRCC1 and OGG1.
Using a functional assay for the removal of the oxidative DNA lesion 8-oxoguanine by the DNA-repair enzyme 8-oxoguanine DNA glycosylase 1 (OGG1), we have previously shown that reduced OGG activity is a risk factor in lung cancer.
In the present study, we investigated the polymorphisms of following selected DNA repair genes: XPC (Lys939Gln), XPD (Lys751Gln), hOGG1 (Ser326Cys) and XRCC1 (Arg399Gln), and the risks they present towards the development of lung cancer with the emphasis to gender differences within the Slovak population.
Although no significant association between any single genetic variant and lung cancer risk was observed, when genetic variants were analyzed in combination, a significant effect on lung cancer risk was found for the variant allele in a combination of five genes involved in oxidative stress and inflammatory response: GSTM1 (null), MPO (-463A), OGG1 (326Cys), TP53 (72Pro) (alias p53), MMP1 (2G).