MicroRNA-340 Mediates Metabolic Shift in Oral Squamous Cell Carcinoma by Targeting Glucose Transporter-1

Purpose: MicroRNA-340 (miR-340) is deregulated in many human cancers in correlation with tumor progression. Recent studies have found that microRNAs play key roles in energy metabolism. This study explored the contributions of miR-340 to the metabolic shift in oral squamous cell carcinoma (OSCC). Materials and Methods: MiR-340 expression was measured by real-time polymerase chain reaction. MiR-340 mimics, miR-340 inhibitor, and scramble small interfering RNA were transfected into SAS human tongue SCC cells to observe their effects on cell proliferation, colony formation, lactate secretion, and glucose uptake rate. Moreover, the relation between the level of miR-340 and glucose transporter-1 (Glut1) was investigated. Results: The expression of miR-340 was decreased and thus induced a metabolic switch in oral cancer cells. The decrease in miR-340 increased Glut1 expression, leading to an increase in lactate secretion and glucose uptake rate. The altered metabolism induced by miR-340 resulted in the rapid proliferation of oral cancer cells. Conclusion: The findings suggest that miR-340 might act as a molecular switch that contributes to the regulation of glycolysis in OSCC by regulating Glut1 expression. (C) 2016 American Association of Oral and Maxillofacial Surgeons