miR-22-3p Suppresses Cell Proliferation and Migration of Gastric Cancer by Targeting ENO1.

Background and Objective: miR-22-3p functions as a tumor suppressor by targeting a variety of downstream genes, while its role and downstream targets in gastric cancer (GC) remain to be determined. We aimed to explore the role of miR-22-3p in gastric cancer and the potential mechanism. Methods: miR-22-3p mimic and inhibitor were used to overexpress or knockdown the expression of miR-22-3p separately. Quantitative real-time PCR (RT-qPCR) and Western blot were used to analyse the abundance of mRNA or protein level respectively. CCK-8 assay, cell colony formation assay, and flow cytometry were implemented to investigate the effect of miR-22-3p on gastric cancer cell proliferation and apoptosis. Luciferase assay was used to evaluate the role of miR-22-3p on the expression of glycolytic enzyme enolase 1 (ENO1). Results: In this study, we found that miR-22-3p was downregulated in GC cells. By transfecting the cells with miR-22-3p inhibitors or mimics, we showed that miR-22-3p suppressed GC cell proliferation and migration, as well as triggered cell death. In addition, we discovered that miR-22-3p was engaged in glycolysis by controlling the generation of lactate as well as the consumption of glucose. TargetScan database suggested that the ENO1 may be a target of the miR-22-3p, and the luciferase experiment verified this hypothesis. Recovery assays showed that the proliferation and migration of GC cells suppressed by miR-22-3p could be rescued by overexpression of ENO1. Conclusion: Collectively, we identified a new axis of miR-22-3p/ENO1 for GC development, which could be investigated as a therapeutic target for GC.