Hepatocellular carcinoma redirects to ketolysis for progression under nutrition deprivation stress

Cell Res. 2016 Oct;26(10):1112-1130. doi: 10.1038/cr.2016.109. Epub 2016 Sep 20.

Abstract

Cancer cells are known for their capacity to rewire metabolic pathways to support survival and proliferation under various stress conditions. Ketone bodies, though produced in the liver, are not consumed in normal adult liver cells. We find here that ketone catabolism or ketolysis is re-activated in hepatocellular carcinoma (HCC) cells under nutrition deprivation conditions. Mechanistically, 3-oxoacid CoA-transferase 1 (OXCT1), a rate-limiting ketolytic enzyme whose expression is suppressed in normal adult liver tissues, is re-induced by serum starvation-triggered mTORC2-AKT-SP1 signaling in HCC cells. Moreover, we observe that enhanced ketolysis in HCC is critical for repression of AMPK activation and protects HCC cells from excessive autophagy, thereby enhancing tumor growth. Importantly, analysis of clinical HCC samples reveals that increased OXCT1 expression predicts higher patient mortality. Taken together, we uncover here a novel metabolic adaptation by which nutrition-deprived HCC cells employ ketone bodies for energy supply and cancer progression.

MeSH terms

  • Animals
  • Autophagy / drug effects
  • Blood Glucose / analysis
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / mortality
  • Carcinoma, Hepatocellular / pathology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Coenzyme A-Transferases / antagonists & inhibitors
  • Coenzyme A-Transferases / genetics
  • Coenzyme A-Transferases / metabolism
  • Culture Media, Serum-Free / pharmacology
  • Hep G2 Cells
  • Humans
  • Hydroxybutyrates / analysis
  • Hydroxybutyrates / metabolism
  • Ketone Bodies / metabolism*
  • Liver / metabolism
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / mortality
  • Liver Neoplasms / pathology*
  • Mechanistic Target of Rapamycin Complex 2 / metabolism
  • Mice
  • Mice, Nude
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / drug effects
  • Sp1 Transcription Factor / metabolism
  • Transplantation, Heterologous

Substances

  • Blood Glucose
  • Culture Media, Serum-Free
  • Hydroxybutyrates
  • Ketone Bodies
  • Sp1 Transcription Factor
  • Mechanistic Target of Rapamycin Complex 2
  • Proto-Oncogene Proteins c-akt
  • Coenzyme A-Transferases
  • 3-ketoacid CoA-transferase