GPX3 hypermethylation in gastric cancer and its prognostic value in patients aged over 60

Abstract

Aim: This study investigated the association between GPX3 methylation and gastric cancer (GC), and explored its prognostic value in patients undergoing radical gastrectomy. Materials & methods: The methylation levels of tumor and paracancerous tissues were detected by quantitative methylation-specific PCR method. Results: GPX3 was hypermethylated in GC (p = 4E-4), and was specific for patients with lymphatic metastasis (+), tumor invasion depth >3 cm and patients with poor differentiation. Additionally, GPX3 hypermethylation predicts a tumor recurrence in patients aged >60 (p = 0.019). Data from The Cancer Genome Atlas (TCGA) further confirmed GPX3 hypermethylation (cg21504918: -0.08 vs -0.25, p = 0.001). Additionally, TCGA showed an inverse correlation between GPX3 methylation and expression (p = 7E-18, r = -0.427). Data analysis of Gene Expression Omnibus (GEO) database showed that 5-aza-2′-deoxycytidine demethylating agent increased GPX3 expression (fold-change >2.19, p = 0.001). Conclusion: Our results indicated GPX3 hypermethylation in GC, and predicted a shorter tumor recurrence time in patients aged >60.