Genetic Variants in One-carbon Metabolism-related Genes Contribute to NSCLC Prognosis in a Chinese Population

Background: One-carbon metabolism plays a critical role in DNA methylation and DNA synthesis. Variants of genes involved in one-carbon metabolism may result in aberrant methylation and/or DNA synthesis inhibition, and ultimately modulate the initiation and progression of tumors. In this study, the authors hypothesized that polymorphisms in one-carbon metabolism-related genes may contribute to the prognosis of nonsmall cell lung cancer (NSCLC).

Methods: The authors screened 57 potentially functional single nucleotide polymorphisms (SNPs) from 11 candidate genes involved in one-carbon metabolism and genotyped them in a cohort of 568 NSCLC patients by using Illumina Golden Gate platform. The Kaplan-Meier method with log-rank test and Cox proportional hazards model were used for survival analyses.

Results: Variant alleles were significantly associated with favorable survivals of NSCLC for MTR rs3768160 A>G (allelic hazards ratio [HR], 0.78; 95% confidence interval [CI], 0.62-0.98), MTRR rs2966952 G>A (allelic HR, 0.84; 95% CI, 0.71-0.99) and DHFR rs1650697 G>A (allelic HR, 0.83; 95% CI, 0.70-0.99) and with unfavorable prognosis for MTHFD1 rs1950902 G>A with borderline significance (allelic HR, 1.18; 95% CI, 0.99-1.40). In addition, the combined genotypes of these four SNPs showed a locus-dosage effect on NSCLC survival (P(trend) = 6.9 × 10(-5) ). In the final multivariate Cox regression model, combined genotypes based on 3 categories may be an independent prognostic factor for NSCLC with adjusted trend HR of 0.78 (95% CI, 0.66-0.92).

Conclusion: Genetic variants in one-carbon metabolism pathway may be candidate biomarkers for NSCLC prognosis.