Tumor-suppressive miR-323a inhibits pancreatic cancer cell proliferation and glycolysis through targeting HK-2.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 85% of all malignant pancreatic exocrine tumors and is one of the main causes of cancer-related fatalities. PDAC is characterized by a high glycolytic rate to ensure its survival as a result of hypovascularization and the desmoplastic reaction. In this study, microRNA 323a (miR-323a) was shown to be downregulated within pancreatic cancer tissues and cells, and enriched in the glucose metabolism pathway. In vitro, overexpression of miR-323a suppressed cell viability, DNA synthesis, and colony formation; in vivo, miR-323a overexpression suppressed the tumor growth within a xenograft mouse model. Regarding cellular glycolysis, miR-323a overexpression decreased glucose-6-phosphate levels, inhibited glucose uptake, and reduced lactate and adenosine triphosphate production. miR-323a was found to directly target hexokinase 2 (HK-2) and negatively regulated HK-2 expression. HK-2 overexpression exerted oncogenic effects on pancreatic cancer cells and promoted cellular glycolysis; more importantly, HK-2 overexpression partially eliminated the effects of miR-323a overexpression. In conclusion, miR-323a is downregulated within pancreatic cancer and serves as a tumor-suppressive miRNA through inhibiting cancer cell proliferation and glycolysis. miR-323a exerts its tumor-suppressive effects through targeting HK-2.