Abstract 4479: Polymorphisms in the nucleotide excision repair genes, ERCC1 and ERCC2/XPD and carcinogen DNA adducts in human lung

Abstract

Abstract Objectives Excision repair cross-complementing group 1 (ERCC1) and excision repair cross-complementing group 2/xeroderma pigmentosum group D (ERCC2/XPD) in the nucleotide excision repair (NER) pathways that removes DNA damage caused by tobacco smoking carcinogen such as polycyclic aromatic hydrocarbons (PAHs). However, no studies have examined their role in DNA adducts in target human lung tissue, a dosimeter for lung cancer risk. Therefore, we investigated whether the polymorphisms in SNPs in NER pathways associated with the DNA adduct formation in human lung tissue. We further analyzed these relationship divided by adenocarcinoma and squamous cell carcinoma, main type of non-small cell lung cancer (NSCLC). Methods The study population consisted of 135 lung cancer patients from the Massachusetts General Hospital (MGH). Genotyping was completed for SNPs in ERCC1 [C8092A (rs3212986) and C118T (rs11615)] and ERCC2/XPD [Asp312Asn (rs1799793) and Lys751Gln (rs1052559)] using PCR-RFLP method and the PCR with fluorescent allele-specific oligonucleotide probes (TaqMan method). DNA adduct levels were measured as relative adduct levels per 1010 nucleotides by 32P-postlabeling in the lung. Multiple regression models were used to estimate adjusted percent change in DNA adduct levels associated with genotypes of the NER genes ERCC1 and ERCC2/XPD. Results After adjusting for potential confounders, DNA adduct levels in lung increased by 73.5% [95% confidence interval (CI), –22.6 to 288.9] for the ERCC2/XPD rs1799793AA genotype and by 43.7% (95% CI, –30.0 to 194.6) for ERCC2/XPD rs1052559GG genotype compared with their corresponding wild type homozygous genotypes in overall lung cancer patients, but it did not reach statistical significance. We found that DNA adducts levels in lung increased by 166.6% (95% CI, –5.0 to 648.3, P = 0.07) for ERCC2/XPD rs1799793AA genotype in patients with squamous cell carcinoma and the trend was borderline significant (P for trend = 0.06). Conclusions Polymorphisms of DNA repair genes, ERCC2/XPD Asp312Asn, may affect increased level of DNA adducts in the lung. Further large scale studies are needed to confirm our findings. Supported by NIH grants CA074386, CA092824, and CA90578. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4479. doi:1538-7445.AM2012-4479