Abstract
BACKGROUND: Peripheral blood leukocyte (PBL) DNA methylation may serve as a surrogate marker to evaluate the susceptibility to and prognosis of gastric cancer (GC). In this study, blood-derived DNA methylation levels of two tumour-related genes, namely, ZNF331 and WIF1, and their impacts on the risk and prognosis of GC were evaluated. METHODS: In total, 398 GC cases and 397 controls were recruited for the study. Then, all cases were followed up for 5 years. ZNF331 and WIF1 promoter methylation status in PBLs was measured using a methylation-sensitive high-resolution melting method. Logistic and Cox regression models were used to analyse the correlation between gene methylation and the risk and prognosis of GC. Confounders were balanced through propensity score (PS) matching. RESULTS: High ZNF331 methylation significantly decreased GC risk after PS adjustment (OR = 0.580, 95% CI: 0.375-0.898, P = 0.015), which also presented in males (OR = 0.577, 95% CI: 0.343-0.970, P = 0.038). However, WIF1 methylation was not associated with GC risk. Additionally, significant combined effects between ZNF331 methylation and the intake of green vegetables and garlic were observed (OR = 0.073, 95% CI: 0.027-0.196, P < 0.001 and OR = 0.138, 95% CI: 0.080-0.238, P < 0.001, respectively). Furthermore, ZNF331 and WIF1 methylation had no impact on the prognosis of GC. CONCLUSION: ZNF331 methylation in PBLs may affect GC risk in combination with the consumption of green vegetables and garlic and may act as a potential biomarker of GC.