MiR-5683 suppresses glycolysis and proliferation through targeting pyruvate dehydrogenase kinase 4 in gastric cancer.

Gastric cancer (GC) is one of the most deadly malignancies at global scale, and is particularly common in eastern Asia. MicroRNA-5683 (miR-5683) was confirmed to be downregulated in GC by analyzing data from the Cancer Genome Atlas. We packaged miR-5683-mimics and miR-5683-inhibitors into lentivirus vectors and transfected them into GC cells. MiR-5683 expression and possible target genes were detected by employing quantitative real-time polymerase chain reaction. In vitro, cell proliferation and apoptosis were analyzed using CCK-8, colony formation assay, and flow cytometric assay. We verified the direct interaction between miR-5683 and the possible downstream target gene pyruvate dehydrogenase kinase 4 (PDK4) through luciferase reporter assay. The role of miR-5683 in vivo was explored by injecting stably transfected GC cells subcutaneously into nude mice. Here we show that miR-5683 was downregulated in GC and the decreased level of miR-5683 enhances GC cell proliferation and impairs apoptosis. Tumor oncogene PDK4, which is associated with GC overall survival and disease-free survival, has been identified as the target gene of miR-5683. Besides, we demonstrate that the inhibition of miR-5683 promotes glycolysis by upregulating the PDK4 expression, thus leading to GC progression. Our study determines that miR-5683 represses GC glycolysis and progression through targeting PDK4. MiR-5683 overexpression may thus become a new treatment strategy for GC.