Suppression of miR-199a maturation by HuR is crucial for hypoxia-induced glycolytic switch in hepatocellular carcinoma.

Glucose metabolic reprogramming is a hallmark of cancer. Cancer cells rapidly adjust their energy source from oxidative phosphorylation to glycolytic metabolism in order to efficiently proliferate in a hypoxic environment, but the mechanism underlying this switch is still incompletely understood. Here, we report that hypoxia potently induces the RNA-binding protein HuR to specifically bind primary miR-199a transcript to block miR-199a maturation in hepatocellular carcinoma (HCC) cells. We demonstrate that this hypoxia-suppressed miR-199a plays a decisive role in limiting glycolysis in HCC cells by targeting hexokinase-2 (Hk2) and pyruvate kinase-M2 (Pkm2). Furthermore, systemically delivered cholesterol-modified agomiR-199a inhibits [(18)F]-fluorodeoxyglucose uptake and attenuates tumor growth in HCC tumor-bearing mice. These data reveal a novel mechanism of reprogramming of cancer energy metabolism in which HuR suppresses miR-199a maturation to link hypoxia to the Warburg effect and suggest a promising therapeutic strategy that targets miR-199a to interrupt cancerous aerobic glycolysis.