Genetic Variation in the NBS1 Gene Is Associated with Hepatic Cancer Risk in a Chinese Population

NBS1 plays important roles in maintaining genomic stability as a key DNA repair protein in the homologous recombination repair pathway and as a signal modifier in the intra-S phase checkpoint. We hypothesized that polymorphisms of NBS1 are associated with hepatic cancer (HCC) risk. The NBS1 rs1805794 C/G polymorphism has been frequently studied in some cancers with discordant results, but its association with HCC has not been investigated. Moreover, studies of the 3'UTR variant rs2735383 have not touched upon HCC. This study examined the contribution of these two polymorphisms to the risk of developing HCC in a Chinese population. NBS1 genotypes were determined in 865 HCC patients and 900 controls and the associations with risk of HCC were estimated by logistic regression. Compared with the rs1805794 GG genotype, the GC genotype had a significantly increased risk of HCC (adjusted odds ratios [OR] = 1.41; 95% confidence interval [CI] = 1.11-1.80), the CC carriers had a further increased risk of HCC (OR = 2.27; 95% CI = 1.68-3.14), and there was a trend for an allele dose effect on risk of HCC (p < 0.001). Also, we found that the risk effect of rs1805794 CC + CG was more pronounced in HCC patients that drank (OR = 2.28, 95% CI = 1.55-3.29 for drinkers; OR = 1.31, 95% CI = 1.00-1.77 for nondrinkers). However, there was no significant difference in genotype frequencies of rs2735383 G/C site between cases and controls. These findings suggest that rs1805794 C/G polymorphism in NBS1 may be a genetic modifier for developing HCC.