Extended Characterization of Activators of Human Muscle isoform 2 Pyruvate Kinase: Summary
The metabolism of cancer cells is altered to support rapid proliferation. Otto Warburg was first to notice that cancer cells produce lactate even in the presence of oxygen [1,2]. This altered metabolism, known as the Warburg effect, is thought to give tumor cells a selective growth advantage relative to normal cells . At least part of this abnormal metabolic phenotype is thought to be due to more ..
Depositor Specified Assays
The metabolism of cancer cells is altered to support rapid proliferation. Otto Warburg was first to notice that cancer cells produce lactate even in the presence of oxygen [1,2]. This altered metabolism, known as the Warburg effect, is thought to give tumor cells a selective growth advantage relative to normal cells . At least part of this abnormal metabolic phenotype is thought to be due to over expression of specific enzymes such as a tumor specific isozyme of pyruvate kinase - PKM2. Pyruvate kinase operates the final rate determining step of glycolysis where the enzyme converts one molecule of phosphoenol pyruvate and ADP to pyruvate and ATP. Recent work has shown that replacement of PKM2 in cancer cells with an isoform found in typical adult tissue cells (PKM1) can relieve the Warburg effect and promote a state of metabolism characteristic of normal cells . Further, tumors engineered to express only PKM1 showed delayed tumor formation in nude mouse xenografts . It has also been demonstrated that PKM2 has high affinity for binding phosphotyrosine peptides that are characteristic of growth factor signaling pathways present in cancer cells . The binding of phosphopeptides to PKM2 removes the allosteric activator fructose-1,6-bisphosphate which further down-regulates the activity of PKM2 and intensifies the Warburg effect. Therefore, pharmacological activators of PKM2 are thought to be an approach for altering the Warburg effect by shifting the glycolytic flux from a proliferative mode back toward normal energy production.
The primary qHTS data of human PKM2 and confirmatory data are available in PubChem (AIDs: 1631, 1751 and 2533). Follow-up of synthesized analogs was determined using the same luminescent protocol for the PK isoforms M1, L and R (PubChem AIDs for M1, L and R bioluminescent assays are 2536, 2535, and 2534, respectively). A fluorescent secondary assay that determined the activity of PK by coupling the production pyruvate to lactate dehydrogenase oxidation of NADH was also used to determine the activation potency of the synthesized analog. (PubChem AIDs: 1540 and 2576 for M2 isoform; 2625, 2620, 2562 for L, M1 and R isoforms respectively). As well, general cytotoxicity of the compounds was measured in HeLa cells using Cell-TiterGlo (Promega; PubChem AID: 2653).
A bis-sulfonamide compound (CID_650361, ML083) and a heteocycle compound (CID_654376, ML082) were identified as human PKM2 activators during the probe phase of the project. These molecules were further characterized in the extended characterization part of the project.
NIH Chemical Genomics Center [NCGC]
NIH Molecular Libraries Probe Production centers Network [MLPCN]
MLPCN Grant: MH085679
Assay Submitter (PI): Matthew G. Vander Heiden