Assessment of the low inhibitory specificity of oxamate, aminooxyacetate and dichloroacetate on cancer energy metabolism

• Published in: Biochimica et biophysica acta. General subjects 2017-01, Vol.1861 (1), p.3221-3236
• Main Authors: Moreno-Sánchez, Rafael, Marín-Hernández, Álvaro, Del Mazo-Monsalvo, Isis, Saavedra, Emma, Rodríguez-Enríquez, Sara
• Format: Article
• Language: English
• Subjects: Aminooxyacetic Acid - pharmacology; Animals; Antineoplastic Agents - pharmacology; Cancer; Cell Line, Tumor; Computer Simulation; Dichloroacetic Acid - pharmacology; Dihydroxyacetone Phosphate - pharmacology; Energy Metabolism - drug effects; Enzyme Inhibitors - pharmacology; Female; Glycolysis; Glycolysis - drug effects; Humans; Kinetic modeling; Kinetics; Metabolic drugs; Mice; Mitochondria, Heart - drug effects; Mitochondria, Heart - metabolism; Models, Molecular; NADP - metabolism; Neoplasms - metabolism; Oxamic Acid - pharmacology; Oxidative phosphorylation; Oxidative Phosphorylation - drug effects; Rats, Wistar; Sus scrofa
• ISSN: 0304-4165; 1872-8006
• DOI: 10.1016/j.bbagen.2016.08.006

Exceedingly high therapeutic/experimental doses of metabolic drugs such as oxamate, aminooxyacetate (AOA) and dichloroacetate (DCA) are required to diminish growth, glycolysis and oxidative phosphorylation (OxPhos) of different cancer cells. To identify the mechanisms of action of these drugs on cancer energy metabolism, a systematic analysis of their specificities was undertaken. Hepatocarcinoma AS-30D cells were treated with the inhibitors and glycolysis and OxPhos enzyme activities, metabolites and fluxes were analyzed. Kinetic modeling of glycolysis was used to identify the regulatory mechanisms. Oxamate (i) not only inhibited LDH, but also PYK and ENO activities inducing an increase in the cytosolic NAD(P)H, Fru1,6BP and DHAP levels in AS-30D cells; (ii) it slightly inhibited HPI, ALD and Glc6PDH; and (iii) it inhibited pyruvate-driven OxPhos in isolated heart mitochondria. AOA (i) strongly inhibited both AAT and AlaT, and 2-OGDH and glutamate-driven OxPhos; and (ii) moderately affected GAPDH and TPI. DCA slightly affected pyruvate-driven OxPhos and Glc6PDH. Kinetic modeling of cancer glycolysis revealed that oxamate inhibition of LDH, PYK and ENO was insufficient to achieve glycolysis flux inhibition. To do so, HK, HPI, TPI and GAPDH have to be also inhibited by the accumulated Fru1,6BP and DHAP induced by oxamate. Oxamate, AOA, and DCA are not specific drugs since they inhibit several enzymes/transporters of the glycolytic and OxPhos pathways through direct interaction or indirect mechanisms. These data explain why oxamate or AOA, through their multisite inhibitory actions on glycolysis or OxPhos, may be able to decrease the proliferation of cancer cells. •Oxamate, aminooxyacetate (AOA) and dichloroacetate (DCA) are not specific drugs.•Oxamate, AOA and DCA inhibit several glycolytic and OxPhos enzymesOxamate inhibition induces Fru1,6BP and DHAP accumulation.•High Fru1,6BP and DAHP levels inhibit HK, HPI, TPI and GAPDH activities.•Kinetic modeling shows that oxamate must affect several enzymes to block glycolysis.