[Study on the association between DNA double-strand break repair gene NBS1 polymorphisms and susceptibility on lung cancer].

Objective: To study the association between DNA double-strand break repair gene NBS1 (nijmegen breakage syndrome gene) polymorphisms and the susceptibility to lung cancer.
Methods: A case-control study design was applied. PCR-RFLP was used to identify NBS1 polymorphisms among 575 lung cancer cases and 575 controls.
Results: The frequencies of C/C, C/G and G/G genotypes at NBS1 rs1805794 site were 25.9%, 51.8%, 22.3% among controls compared to 20.5%, 52.3%, 27.1% among cases. There was significant difference between controls and cases (χ(2) = 6.38, P = 0.04). Individuals carrying C/G + G/G genotypes had an increased risk for lung cancer (OR = 1.46, 95%CI: 1.09 - 1.97) compared to the C/C genotype. The frequencies of G/G, G/C and C/C genotypes at NBS1 rs2735383 site were 37.9%, 47.0%, 15.1% among controls compared to 35.5%, 48.5%, 16.0% among cases, with no significant difference between the two groups (χ(2) = 0.75, P = 0.69). Individuals carrying Hap4-GC haplotype (OR = 1.70, 95%CI: 1.24 - 2.31) and Hap4/Hap2 dihaplotype (OR = 1.75, 95%CI: 1.11 - 2.76) had an increased risk on lung cancer. Joint associations of smoking and the NBS1 polymorphism with the risk of lung cancer were observed (P < 0.05).
Conclusion: The G/G genotype at NBS1 rs1805794 site and the Hap4-GC haplotype and Hap4/Hap2 di haplotype from rs1805794 and rs2735383 were both associated with lung cancer.