Targeting mitochondria as an anticancer strategy

Mitochondria are organelles controlling adenosine triphosphate (ATP) generation, redox homeostasis, metabolic signaling, and apoptotic pathways. Although glycolysis was traditionally considered as the major source of energy in cancer cells, in-line with the so-called “Warburg effect”, mitochondria have been recognized to play a key role in oncogenesis [1]. Cancer cells uniquely reprogram their cellular activities to support their rapid proliferation and migration, as well as to counteract metabolic and genotoxic stress during cancer progression [2]. Further, mitochondria can switch their metabolic phenotypes to meet the challenges of high energy demand and macromolecular synthesis [3]. Thus, cancer mitochondria have the ability to flexibly switching between glycolysis and oxidative phosphorylation (OXPHOS) for their survival. The electron transport chain (ETC) function is pivotal for mitochondrial respiration, which is also needed for dihydroorotate dehydrogenase (DHODH) activity that is essential for de novo pyrimidine synthesis [4]. Recent researches have demonstrated that cancer cells devoid of mitochondrial DNA (mtDNA) lack their tumorigenic potential, and they re-gain this ability by acquiring healthy mtDNA from the host stromal cells via horizontal transfer of whole mitochondria [5, 6] for recovery of the respiratory function. Functionally, respiration propels DHODH activity for pyrimidine biosynthesis [7]. Therefore, targeting mitochondria holds great potential for anticancer strategy with high therapeutic opportunities.