THE METABOLIC PHENOTYPE OF PANCREATIC CANCER AND ITS LINK TO CYTOSOLIC CALCIUM HOMEOSTASIS AND SURVIVAL

  • Anthony Chan

Student thesis: Unknown

Abstract

THE METABOLIC PHENOTYPE OF PANCREATIC CANCER AND ITS LINK TO CYTOSOLIC CALCIUM HOMEOSTASIS AND SURVIVAL IntroductionPancreatic ductal adenocarcinoma (PDAC) is an insidious and aggressive cancer characterised by poor survival rates. In cancer, there is a pathological switch in metabolism from mitochondrial oxidative phosphorylation to glycolysis, known as the Warburg effect. Cells depend on an ATP-driven plasma membrane Ca¬2+ pump (PMCA) to maintain a low resting cytosolic Ca2+ concentration ([Ca2+]i), high levels of which can produce cytotoxicity and cell death. The reliance of PDAC on glycolysis can be targeted by selective metabolic inhibitors. We hypothesize that disrupting the glycolytic ATP supply will impair PMCA, and its ability to maintain a low resting [Ca2+]i that prevents cell death.Methods & MaterialsTo measure the effect of glycolytic and mitochondrial inhibitors, we utilised an in situ PMCA activity Fura-2 assay to measure [Ca2+]i clearance in the PDAC cell line, Panc-1. We also measured the effects of the inhibitors on intracellular ATP levels using bioluminescence assays, and cell necrosis rates using cell death assays.ResultsWe firstly show that selective inhibition of glycolysis using 3-bromopyruvate (3-BP) induces cell necrosis in Panc-1 cells whereas inhibition of mitochondrial metabolism using carbonyl cyanide m-chlorophenyl hydrazone (CCCP) has no effect. Furthermore, we show that glycolytic inhibitors 3-BP and iodoacetate inhibits PMCA, and impairs the ability of the Panc-1 cells to maintain Ca2+ homeostasis. Mitochondrial inhibitors CCCP and oligomycin has no effect on Ca2+ clearance. Finally, we show that inhibition of glycolysis, but not mitochondrial metabolism, causes a significant reduction in intracellular ATP levels in Panc-1 cells.DiscussionOur data suggests that an inhibition of the glycolytic ATP supply to PMCA in PDAC is an effective therapeutic target that could represent a new strategy for selectively killing PDAC cells and sparing normal, healthy cells.
Date of Award31 Dec 2013
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorAjith Siriwardena (Supervisor) & Jason Bruce (Supervisor)

Keywords

  • Pancreas Cancer
  • Calcium Homeostasis

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