Bastos Sant'Anna Silva 2018 MiPschool Tromso C4
Event: MiPschool Tromso-Bergen 2018
Succinate dehydrogenase (SDH, mitochondrial Complex II) links the oxidation of succinate and FAD to fumarate and FADH2 in the tricarboxylic acid (TCA) cycle to electron transfer (ET) from FADH2 to ubiquinone in the ET system. Changes in ET capacity through the succinate pathway affect TCA cycle function and cell respiration . In addition, succinate transmits oncogenic signals from mitochondria to the cytosol by stabilization of hypoxia inducible factor 1α. This, in turn, stimulates the expression of genes involved in angiogenesis and anaerobic metabolism , finally enabling tumour progression and metastasis. Succinate uptake is enhanced in various cancer cells and its mitochondrial utilisation is increased in permeabilized prostate cancer cells .
To decipher the pathophysiological role of succinate in prostate cancer, we tested the plasma membrane permeability for succinate and utilization of external succinate by mitochondria in terms of succinate pathway capacity and kinetic properties in prostate cancer (multiple metastatic origins) and control cell lines. Respiration in RWPE-1 (prostate; noncancerous), LNCaP (prostate; lymph node metastasis) and DU145 (prostate; brain metastasis) cells was measured using high-resolution respirometry (O2k, Oroboros Instruments) and substrate-uncoupler-inhibitor titration (SUIT) protocols developed specifically for the study. To assess succinate utilization in intact cells independent of a plasma membrane succinate transporter, we applied novel plasma membrane-permeable succinate prodrugs (pS) .
In LNCaP cells, transport of external succinate is enhanced through the plasma membrane as compared to the other cell lines, while pS exerted similar effects in all cell lines, suggesting an important regulatory role of the transport mechanism. Furthermore, in LNCaP cells, mitochondria utilize succinate with higher affinity than control cells. Importantly, kinetic measurements demonstrated the most pronounced difference in the affinities in the physiological intracellular succinate concentration range (< 100 μM), underlining its pathophysiological role.
Our results indicate a “succinate-phenotype” in LNCaP, with enhanced transport and utilization. As such, succinate is a potential mitochondrial metabolic biomarker in prostate cancer cells. We propose a model in which succinate does not only play a role in the signalling but has a central role in the maintenance of mitochondrial respiration as a fuel substrate.
Bastos Sant'Anna Silva AC(1,2), Klocker H(3), Weber A(3), Elmér E(4), Meszaros AT(1,2), Gnaiger E(1,2)
- Oroboros Instruments, Innsbruck
- Daniel Swarovski Research Lab, Dept Visceral, Transplant Thoracic Surgery, Medical Univ Innsbruck
- Dept Urology, Medical Univ Innsbruck; Austria
- Dept Clinical Sciences, Lund Univ, Sweden.
Supported by the Marie Skłodowska-Curie PhD Fellowship TRANSMIT. Membrane permeable prodrugs by NeuroVive.
- Schöpf B, Schäfer G, Weber A, Talasz H, Eder IE, Klocker H, Gnaiger E (2016) Oxidative phosphorylation and mitochondrial function differ between human prostate tissue and cultured cells. FEBS J 283:2181-96.
- Tretter L, Patocs A, Chinopoulos C (2016) Succinate, an intermediate in metabolism, signal transduction, ROS, hypoxia, and tumorigenesis. Biochim Biophys Acta 1857:1086-101.
- Zhunussova A, Sen B, Friedman L, Tuleukhanov S, Brooks AD, Sensenig R, Orynbayeva Z (2015) Tumor microenvironment promotes dicarboxylic acid carrier-mediated transport of succinate to fuel prostate cancer mitochondria. Am J Cancer Res 5:1665-79.
- Ehinger JK, Piel S, Ford R, Karlsson M, Sjövall F, Frostner EÅ, Morota S, Taylor RW, Turnbull DM, Cornell C, Moss SJ, Metzsch C, Hansson MJ, Fliri H, Elmér E (2016) Cell-permeable succinate prodrugs bypass mitochondrial complex I deficiency. Nat Commun 7:12317.
Labels: MiParea: Respiration Pathology: Cancer
Organism: Human Tissue;cell: Genital Preparation: Intact cells Enzyme: Complex II;succinate dehydrogenase
Coupling state: LEAK, ROUTINE, OXPHOS, ET Pathway: S, ROX HRR: Oxygraph-2k, O2k-Protocol Event: C4, Oral