The Contribution of DNA Ligase 4 Genetic Variations to Taiwanese Lung Cancer.

BACKGROUND/AIM: Impaired non-homologous end-joining DNA repair capacity may have a significant role in maintaining genome integrity and triggering carcinogenesis. However, the specific impact of DNA ligase 4 (Lig4) genotypes remains unclear. This study aimed to assess the contribution of Lig4 genotypes to the risk of developing lung cancer. MATERIALS AND METHODS: Polymerase chain reaction-restriction fragment length polymorphism analysis was used to examine the genotypes of Lig4 rs1805388, and their association with lung cancer risk was evaluated in a case-control study consisting of 358 lung cancer cases and 716 age- and sex-matched cancer-free control subjects. RESULTS: The distribution of CC, CT, and TT genotypes for Lig4 rs1805388 among the cases was 45.0%, 41.6%, and 13.4%, respectively, compared to 58.0%, 36.3%, and 5.7% among the controls (p for trend=1.98×10-6). Allelic analysis indicated that individuals carrying the T-allele for Lig4 rs1805388 had a 1.66-fold higher risk of developing lung cancer compared to those carrying the wild-type C-allele [95% confidence interval (CI)=1.36-2.02, p=4.04×10-7]. Moreover, a significant interaction was observed between the Lig4 rs1805388 genotype and smoking status (p=1.32×10-7). CONCLUSION: These findings suggest that the CT and TT variant genotypes of Lig4 rs1805388, combined with cigarette smoking, may contribute to a higher risk of developing lung cancer.

The Association of DNA Ligase 1 Rs20579 Polymorphism With Lung Cancer Risk Among Taiwanese.

BACKGROUND/AIM: Impaired DNA repair capacity may play a critical role in genome instability and carcinogenesis. However, the impact of DNA ligase 1 (Lig1) genotypes on tumorigenesis remains unclear. This study aimed to investigate the contribution of Lig1 rs20579 genotypes to the risk of developing lung cancer, and review the related literature. MATERIALS AND METHODS: Polymerase chain reaction-restriction fragment length polymorphism analysis was used to determine the genotypes of Lig1 rs20579 and evaluate their association with lung cancer risk among 358 lung cancer cases and 716 age- and sex-matched cancer-free control subjects. RESULTS: The distribution of GG, AG, and AA genotypes for Lig1 rs20579 was 77.1%, 20.8%, and 2.1% among the controls, and 76.0%, 21.5%, and 2.5% among the lung cancer cases (p for trend=0.8686). There was no significant difference in the distribution of AG and AA genotypes between the two groups (p=0.8257 and 0.8098, respectively). Allelic frequency analysis indicated that individuals carrying the variant A allele for Lig1 rs20579 had a non-significant 1.07-fold higher risk of developing lung cancer than those carrying the wild-type G allele [95% confidence interval (CI)=0.82-1.40, p=0.6639]. Furthermore, no differential distribution of the Lig1 rs20579 genotype was found among non-smokers (p=0.9910) or smokers (p=0.9001). CONCLUSION: In contrast to Americans, Lig1 rs20579 genotypes do not appear to play a critical role in determining susceptibility to lung cancer among Taiwanese individuals.