title: Metabolomic comparison between cells over-expressing isocitrate dehydrogenase 1 and 2 mutants and the effects of an inhibitor on the metabolism.
abstract: The R132H and R172K mutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) have neomorphic activity of generating 2-hydroxyglutarate (2-HG) which has been implicated in the oncogenesis. Although similarities in structure and enzyme activity for the two isotypic mutations have been suggested, the difference in their cellular localization and biochemical properties suggests differential effects on the metabolic oncogenesis. Using U87 cells transfected with either wild-type (WT) and mutant (MT) IDH genes, the MT-IDH1 and MT-IDH2 cells were compared with NMR-based metabolomics. When normalized with the respective WT-IDH cells, the general metabolic shifts of MT-IDH1 and IDH2 were almost opposite. Subsequent analysis with LC-MS and metabolic pathway mapping showed that key metabolites in pentose phosphate pathway and tricarboxylic acid cycle are disproportionately altered in the two mutants, suggesting different activities in the key metabolic pathways. Notably, lactate level was lower in MT-IDH2 cells which produced more 2-HG than MT-IDH1 cells, indicating that the Warburg effects can be overridden by the production of 2-HG. We also found that the effect of a mutant enzyme inhibitor is mainly reduction of the 2-HG level rather than general metabolic normalization. Overall, the metabolic alterations in the MT-IDH1 and 2 can be different and seem to be commensurate with the degree of 2-HG production. The R132H and R172K mutations of isocitrate dehydrogenase 1 and 2, respectively, (IDH1 and IDH2) have neomorphic activity of generating 2-hydroxyglutarate (2-HG) which has been implicated in oncogenesis. The mutant cell's metabolic shifts from the respective wild type cells were almost opposite, with lactate level being lower in the IDH2 mutant only, implicating an overridden Warburg effect. The metabolic effect of an IDH1 mutant inhibitor was limited to 2-HG lowering.
authors.affiliation: College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul, Korea.
authors.forename: He
authors.initials: H
authors.lastname: Wen
authors.forename: Hye Rim
authors.initials: HR
authors.lastname: Cho
authors.forename: Taeho
authors.initials: T
authors.lastname: Yun
authors.forename: Hyeonjin
authors.initials: H
authors.lastname: Kim
authors.forename: Chul-Kee
authors.initials: CK
authors.lastname: Park
authors.forename: Se-Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
authors.forename: Sunghyouk
authors.initials: S
authors.lastname: Park
mesh_terms: D044482:Benzeneacetamides / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D002853:Chromatography, Liquid; D002952:Citric Acid Cycle / Q000235:genetics; D005910:Glioma / Q000201:enzymology / Q000473:pathology; D005977:Glutarates / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000737:chemistry / Q000494:pharmacology*; D007521:Isocitrate Dehydrogenase / Q000037:antagonists & inhibitors* / Q000235:genetics; D013058:Mass Spectrometry; D055442:Metabolome; D015394:Molecular Structure; D020125:Mutation, Missense; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics; D019906:Nuclear Magnetic Resonance, Biomolecular; D010427:Pentose Phosphate Pathway / Q000235:genetics; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: C581156:AGI-5198; D044482:Benzeneacetamides; D005977:Glutarates; D007093:Imidazoles; D009363:Neoplasm Proteins; D011993:Recombinant Fusion Proteins; C019417:alpha-hydroxyglutarate; C538784:IDH2 protein, human; D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human
keywords: 2-hydroxyglutarate; inhibitor; isocitrate dehydrogenase; metabolomics