Paracrine Hedgehog Signaling Drives Metabolic Changes in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) typically develop in cirrhosis, a condition characterized by Hedgehog (Hh) pathway activation and accumulation of Hh-responsive myofibroblasts (MF). Although Hh signaling generally regulates stromal-epithelial interactions that support epithelial viability, the role of Hh-dependent MF in hepatocarcinogenesis is unknown. Here we used human HCC samples, a mouse HCC model, and hepatoma cell/MF co-cultures to examine the hypothesis that Hh signaling modulates MF metabolism to generate fuels for neighboring malignant hepatocytes. The results identify a novel paracrine mechanism whereby malignant hepatocytes produce HH-ligands to stimulate glycolysis in neighboring MF, resulting in release of MF-derived lactate that the malignant hepatocytes use as an energy source. This discovery reveals new diagnostic and therapeutic targets that might be exploited to improve the outcomes of cirrhotic patients with HCC.