Mitochondria-targeted antioxidant and glycolysis inhibition: synergistic therapy in hepatocellular carcinoma

Anticancer Drugs. 2013 Oct;24(9):881-8. doi: 10.1097/CAD.0b013e32836442c6.


Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Mito-carboxy proxyl (Mito-CP), a lipophilic cationic nitroxide, accumulates in the mitochondria because of the large negative transmembrane potential. Studies have shown that these agents act by disrupting the energy-producing mechanism, inducing mitochondrial-mediated apoptosis, and also enhancing the action of other chemotherapeutic agents in cancer cells. We hypothesized that the combination of Mito-CP and glycolysis inhibitor, 2-deoxyglucose (2-DG), would synergistically inhibit HCC in vitro. HepG2 cells and primary hepatocytes were treated with various combinations of Mito-CP and 2-DG. Cell cytotoxicity was measured using the methylthiazolyldiphenyl-tetrazolium bromide assay and ATP bioluminescence assay. In addition, caspase 3/7 enzymatic activity was examined after treatment. Mito-CP and 2-DG induced synergistic cytotoxicity in HepG2 cells in a dose-dependent and time-dependent manner, whereas primary cells remained viable and unaffected after treatment. The intracellular ATP levels of HepG2 cells were suppressed within 6 h of combination treatment, whereas primary cells maintained higher levels of ATP. Dose-dependent increases in caspase 3/7 activity occurred in HepG2 cells in a time-dependent manner, showing the initiation of cell death through the apoptotic pathway. These findings indicate that a combination of Mito-CP and 2-DG effectively inhibits HCC growth in vitro. The increase in caspase 3/7 activity supports the occurrence of 2-DG-induced and Mito-CP-induced apoptotic death in HCC. The inability of the compounds to induce cytotoxicity or suppress the production of ATP in primary hepatocytes provides a selective and synergistic approach for the treatment of HCC.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / pharmacology*
  • Antioxidants / adverse effects
  • Antioxidants / pharmacology*
  • Apoptosis / drug effects
  • Carcinoma, Hepatocellular / drug therapy*
  • Carcinoma, Hepatocellular / enzymology
  • Carcinoma, Hepatocellular / metabolism
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cyclic N-Oxides / adverse effects
  • Cyclic N-Oxides / pharmacology
  • Deoxyglucose / adverse effects
  • Deoxyglucose / pharmacology
  • Drug Synergism
  • Enzyme Inhibitors / adverse effects
  • Enzyme Inhibitors / pharmacology*
  • Glycolysis / drug effects*
  • Hep G2 Cells
  • Humans
  • Kinetics
  • Liver / cytology
  • Liver / drug effects
  • Liver / metabolism
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / enzymology
  • Liver Neoplasms / metabolism
  • Mitochondria, Liver / drug effects*
  • Mitochondria, Liver / enzymology
  • Mitochondria, Liver / metabolism
  • Molecular Targeted Therapy
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / metabolism
  • Organophosphorus Compounds / adverse effects
  • Organophosphorus Compounds / pharmacology


  • Antineoplastic Agents
  • Antioxidants
  • Cyclic N-Oxides
  • Enzyme Inhibitors
  • Neoplasm Proteins
  • Organophosphorus Compounds
  • mito-carboxy proxyl
  • Adenosine Triphosphate
  • Deoxyglucose