Rs3212986 polymorphism, a possible biomarker to predict smoking‐related lung cancer, alters DNA repair capacity via regulating ERCC1 expression

ERCC1 C8092A (rs3213986) within 3′UTR of ERCC1 was associated with an increased risk of lung cancer, especially in smoking population, and therefore could be used as a valuable tumor marker. Although it was also located within the ORF of CD3EAP gene, its effects on the DRC toward BPDE induced DNA damage mainly via modulating ERCC1 expression, but not CD3EAP.

Abstract

Single nucleotide polymorphisms (SNPs) in 3′UTR of key DNA repair enzyme genes are associated with inter‐individual differences of DNA repair capacity (DRC) and susceptibility to a variety of human malignancies such as lung cancer. In this study, seven candidate SNPs in 3′UTR of DRC‐related genes including ERCC1 (rs3212986, rs2336219, and rs735482), OGG1 (rs1052133), MLH3 (rs108621), CD3EAP (rs1007616), and PPP1R13L (rs6966) were analyzed in 300 lung cancer patients and controls from the northeast of China. Furthermore, we introduced ERCC1 (CDS+3′UTR) or CD3EAP (CDS) cDNA clone to transfect HEK293T and 16HBE cells. Cell viability between different genotypes of transfected cells exposed to BPDE was detected by CCK‐8 assay, while DNA damage was visualized using γH2AX immunofluorescence and the modified comet assay. We found that minor A‐allele of rs3212986 could reflect a linkage with increasing risk of NSCLC. Compared with CC genotype, AA genotype of ERCC1 rs3212986 was a high‐risk factor for NSCLC (OR = 3.246; 95%CI: 1.375‐7.663). Particularly stratified by smoking status in cases and controls, A allele of ERCC1 rs3212986 also exhibited an enhanced risk to develop lung cancer in smokers only (P < 0.05). Interestingly, reduced repair efficiency of DNA damage was observed in 293T ERCC1(AA) and 16HBE ERCC1(AA), while no significant difference was appeared in two genotypes of CD3EAP (3′ adjacent gene of ERCC1) overexpressed cells. Our findings suggest that rs3212986 polymorphism in 3ʹUTR of ERCC1 overlapped with CD3EAP may affect the repair of the damage induced by BPDE mainly via regulating ERCC1 expression and become a potential biomarker to predict smoking‐related lung cancer.

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