A strategy for poisoning cancer cell metabolism: Inhibition of oxidative phosphorylation coupled to anaplerotic saturation

The combination of inhibitor of oxidative phosphorylation (OXPHOS) with dimethyl-alpha-ketoglutarate, a cell-permeable precursor of alpha-ketoglutarate, is highly efficient in killing human cancer cells in vitro or in vivo, in xenotransplanted mice. This effect involves excessive anaplerosis, as demonstrated by the fact that inhibition of isocitrate dehydrogenase-1, IDH1, reduced the efficacy of cancer cell killing by the combination treatment. However, the signal transduction pathway leading to cell death turned out to be complex because it involved numerous atypical cell death effectors (such as AIF, APEX, MDM2, PARP1), as well as a profound remodeling of the transcriptome resulting in reduced expression of glycolytic enzymes. The combined inhibition of OXPHOS and glycolytic ATP generation culminated in a lethal bioenergetic catastrophe.