1. Energy metabolism and redox - the cancer cell scenario Maria Shoshan, Cancer Center Karolinska

2. 24 oktober 2015Maria Shoshan2 life & death metabolism redox Fuels are consumed - oxidized - - in order to build something new. This requires reductive events

3. 24 oktober 2015Maria Shoshan3 life & death metabolism redox Cancer cells: - increased macromolecule synthesis - increased ox stress - decreased apoptosis

4. 24 oktober 2015Maria Shoshan4 Hanahan and Weinberg, 2000 ”The Hallmarks of Cancer” Altered energy metabolism Immune system

5. 24 oktober 2015Maria Shoshan5 High glycolytic rate - aerobic glycolysis High uptake of glucose High expression of GLUT1-3 Tumor cells have:

6. 24 oktober 2015Maria Shoshan6 Normal cells: 95% of ATP from mitochondria - electron transport chain, ox-phos… Tumor cells: 40-60% of ATP is via glycolysis

7. 24 oktober 2015Maria Shoshan7 Advantages for the tumor cell: Glucose Glu-6-P ATP; Amino acids Fatty acids Pyruvate acetyl-CoA Purine synthesis Krebs cycle, ATP via mitoch. NADPHglut; ser

8. 24 oktober 2015Maria Shoshan8 Advantages for the tumor cell: Glucose Glu-6-P ATP; Amino acids Fatty acids Pyruvate acetyl-CoA Krebs cycle, ATP via mitoch. glut; ser Anti-apoptotic via AKT/HXK lactate

9. 24 oktober 2015Maria Shoshan9 What comes first - transformation, decreased ox-phos or metabolic adaptations?

10. 24 oktober 2015Maria Shoshan10 Oncogenic signaling Redox events Metabolic alterations

11. 24 oktober 2015Maria Shoshan11 Oncogenic signaling Mitochondrial effects Glycolytic effects Mutations in SDH and FH (complex II, Krebs cycle) Loss of p53 leading to loss of SCO2 ( complex IV ) Loss of p53 leading to increased PGM (glycolysis) Loss of PTEN leading to sustained AKT activity (glycolysis)

12. 24 oktober 2015Maria Shoshan12 Increased HIF1  (glycolysis) - by hypoxia, via ablation of PHD and mito-ROS - by anomalous inhibition of PHD (succinate, fumarate, oxaloacetate, pyruvate; H 2 O 2 ) - by loss of p53, or loss of PTEN Metabolism Oncogenic signaling PHD Glycolysis & PDK1 HIF + O 2 HIF OH degradation Fe 2+ Fe 3+ + ascorbate RNS (iNOS + ROS) FIH-1 - another regulatory hydroxylase

13. 24 oktober 2015Maria Shoshan13 HIF1 repression of differentiation stimulation of angiogenesis IGF, MMP-2 extracellular acidification Tumor progression High levels of HIF1a correlate with poor prognosis

14. 24 oktober 2015Maria Shoshan14 Loss of PTEN leads to increased AKT activity PTEN phosphatase PI3K AKT- P Metabolism Growth; anti-apoptosis PTEN is a tumor suppressor. PTEN mutations are common in human cancer. PTEN is inhibited by oxidization (two Cys). PI3K O 2 * - PTEN inhibition PTPase inhibition In a growth-factor stimulated cell (or with onco-Ras) : Nox Nox: NADPH oxidases

15. 24 oktober 2015Maria Shoshan15 PTEN is inactivated upon impaired respiration Resp./ETCAccumulation of NADH (Krebs cycle) NADHPTEN reactivation, by competing with NADPH Pelicano et al., 2006 PTEN is reduced (activated) by NADPH-TrxR/Trx PTEN(ox) PTEN(red) Helps keep AKT- mediated glycolytic metabolism in check NADPH NADP + TrxR/Trx PTEN can also be inhibited by Trx-1 binding.

16. 24 oktober 2015Maria Shoshan16 17 ov ca ascitic samples were tested in vitro for antiproliferative effects of cisplatin ± DG, a glycolysis inhibitor. In 10 samples, DG reduced individual IC 50 :s by >50%; these were classified as HP (high- potentiated). Low levels of ß-ATPase protein correlated with sensitivity to potentiation. Hernlund et al., MCT 2009 Impaired respiration supports oncogenic signaling - impaired respiration correlates with increased glycolytic dependence, tumor progression and chemoresistance - mtDNA mutations - sustained hypoxia, HIF1a - sustained PTEN inactivation / AKT activation

17. 24 oktober 2015Maria Shoshan17 ROS from growth factor/GFR signaling NAD(P)H oxidases (Nox) - Nox family upregulation in cancer - ROS stimulation of growth and motility - inhibit PTPs - Rac1 - also target TFs AP-1, NFkB ROS in cancer cells:

18. 24 oktober 2015Maria Shoshan18 ROS in cancer cells: Mitochondrial ROS: Higher metabolic rate; Impaired respiration/ETC; Decreased antioxidant defense Fewer mitochondria ROS-sensitive mitoch enzymes Fe/S (aconitase & other Krebs cycle enz., COX) Thiols RNS, peroxynitrite; iNOS (mtNOS?) ROS induction by chemotherapy

19. 24 oktober 2015Maria Shoshan19 Pervaiz & Clement, 2007 e.g., caspase inhibition PTEN inhibition e.g., via modif. of cardiolipin, cyto c release, caspase activation Opposite effects of superoxide and peroxide?

20. 24 oktober 2015Maria Shoshan20 Pouyss é gur et al., Nature review 2006 Higher intracellular pH in cancer cells - and lower extracellular pH NHE-1 : Na + /H + exchanger-1 MCT1-4 : monocarboxylate transp. CA IX : carbonic anhydrase AE : Cl-/HCO3- transporter Possible therapeutic targets! Cancer cells may use lactate to fuel Krebs/ox-phos

21. 24 oktober 2015Maria Shoshan21 Oncogenic signaling Redox events Metabolic alterations AKT HIF1a GFR/NOX Ras AKT HIF1a p53 Hypoxia Mitoch. functions ROS, RNS pH

22. 24 oktober 2015Maria Shoshan22 NADH, FADH 2 e-e- pyruvateKrebs cycle CO 2 O2O2 H 2 O and ROS