Bastos Sant'Anna Silva 2018 Life Sciences Meeting 2018 Innsbruck AT
|Effect of cell-permeable succinate and malonate prodrugs on mitochondrial respiration in prostate cancer cells.|
Succinate is a substrate mainly metabolized to fumarate in mitochondria by succinate dehydrogenase (SDH) or Complex II. SDH is located at the inner mitochondrial membrane, coupling the oxidation of succinate to fumarate in the tricarboxylic acid cycle (TCA) with electron transfer to ubiquinone. Inhibition or downregulation of SDH leads to an impairment of TCA cycle and respiratory activity, and consequently to accumulation of succinate. This, in turn, transmits an oncogenic signal from mitochondria to the cytosol. Cytosolic succinate inhibits the hypoxia inducible factor 1α (HIF1α) prolyl hydroxylase (PHD) leading to HIF1α stabilization. In this “pseudohypoxic” state angiogenesis and anaerobic metabolism are enhanced, ultimately leading to tumour progression.
While succinate has essential implications on prostate cancer development, it is difficult to control intracellular succinate concentrations in intact cells due to the low permeability of plasma membranes to the compound. To overcome this limitation, we applied novel plasma membrane-permeable succinate (NV118) and malonate (inhibitor of SDH, NV161) prodrugs in high-resolution respirometry (Oroboros O2k-FluoRespirometer). Mitochondrial respiration was assessed in three cell lines: RWPE-1 (prostate; noncancerous), LNCaP (prostate; cancer), and HEK293T (embryonic kidney; control).
NV118 (250 µM) stimulated ROUTINE respiration in LNCaP cancer cells by 18% as compared to vehicle (DMSO), while respiration remained unchanged in RWPE-1 (4% increase) and HEK 293T cells, even at higher concentrations of the prodrug. NV161 (66 µM) had no effect on ROUTINE respiration of HEK 293T cells.
Our results indicate enhanced utilization of external, plasma membrane-permeable succinate in mitochondrial respiration in LNCaP prostate cancer cells but not in control cell lines. The cell-permeable prodrugs offer promising research tools to elucidate the roles of succinate and inhibition of SDH in metabolic reprograming towards a malignant phenotype.
• Keywords: mitochondrial respiration, intact cells, cell-permeable succinate • Bioblast editor: Sant'Anna-Silva ACB, Kandolf G • O2k-Network Lab: AT Innsbruck Gnaiger E, AT Innsbruck Oroboros, SE Lund Elmer E
Labels: MiParea: Respiration, Pharmacology;toxicology Pathology: Cancer
Tissue;cell: Kidney, Other cell lines, HEK Preparation: Intact cells, Permeabilized cells Enzyme: Complex II;succinate dehydrogenase Regulation: Calcium, Substrate Coupling state: ROUTINE
HRR: Oxygraph-2k Event: Oral
- Sant´Anna-Silva ACB(1,2), Elmer E(3), Meszaros AT(1,4), Gnaiger E(1,2)
- Oroboros Instruments, Innsbruck, Austria. - [email protected]
- Daniel Swarovsky Inst, Medical Univ Innsbruck, Innsbruck, Austria
- Lund Univ, Sweden
- Inst Surgical Research, Univ Szeged, Hungary