title: Alterations in cellular metabolome after pharmacological inhibition of Notch in glioblastoma cells.
abstract: Notch signaling can promote tumorigenesis in the nervous system and plays important roles in stem-like cancer cells. However, little is known about how Notch inhibition might alter tumor metabolism, particularly in lesions arising in the brain. The gamma-secretase inhibitor MRK003 was used to treat glioblastoma neurospheres, and they were subdivided into sensitive and insensitive groups in terms of canonical Notch target response. Global metabolomes were then examined using proton magnetic resonance spectroscopy, and changes in intracellular concentration of various metabolites identified which correlate with Notch inhibition. Reductions in glutamate were verified by oxidation-based colorimetric assays. Interestingly, the alkylating chemotherapeutic agent temozolomide, the mTOR-inhibitor MLN0128, and the WNT inhibitor LGK974 did not reduce glutamate levels, suggesting that changes to this metabolite might reflect specific downstream effects of Notch blockade in gliomas rather than general sequelae of tumor growth inhibition. Global and targeted expression analyses revealed that multiple genes important in glutamate homeostasis, including glutaminase, are dysregulated after Notch inhibition. Treatment with an allosteric inhibitor of glutaminase, compound 968, could slow glioblastoma growth, and Notch inhibition may act at least in part by regulating glutaminase and glutamate.
authors.affiliation: Department of Pathology, Division of Neuropathology, Johns Hopkins Hospital, Baltimore, MD.|Department of Neurosurgery, University Medical Center, Forschungsgebaeude Pathologie, Düsseldorf, Germany.
authors.forename: Ulf D
authors.initials: UD
authors.lastname: Kahlert
authors.affiliation: Division of Cancer Imaging Research, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, MD.
authors.forename: Menglin
authors.initials: M
authors.lastname: Cheng
authors.affiliation: Department of Neurosurgery, University Medical Center, Forschungsgebaeude Pathologie, Düsseldorf, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Koch
authors.affiliation: Department of Oncology, Johns Hopkins Hospital, Baltimore, MD.|Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Luigi
authors.initials: L
authors.lastname: Marchionni
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, MI.|Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI.
authors.forename: Xing
authors.initials: X
authors.lastname: Fan
authors.affiliation: Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD.|Department of Pediatric Oncology, Johns Hopkins Hospital, Baltimore, MD.
authors.forename: Eric H
authors.initials: EH
authors.lastname: Raabe
authors.affiliation: Department of Neurosurgery, University Medical Center, Forschungsgebaeude Pathologie, Düsseldorf, Germany.
authors.forename: Jarek
authors.initials: J
authors.lastname: Maciaczyk
authors.affiliation: Division of Cancer Imaging Research, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, MD.|Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Kristine
authors.initials: K
authors.lastname: Glunde
authors.affiliation: Department of Pathology, Division of Neuropathology, Johns Hopkins Hospital, Baltimore, MD.
authors.forename: Charles G
authors.initials: CG
authors.lastname: Eberhart
mesh_terms: D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D045744:Cell Line, Tumor; D003499:Cyclic S-Oxides / Q000494:pharmacology; D005909:Glioblastoma / Q000188:drug therapy* / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D005972:Glutaminase / Q000037:antagonists & inhibitors; D006706:Homeostasis; D006801:Humans; D055442:Metabolome; D051880:Receptors, Notch / Q000037:antagonists & inhibitors*; D013830:Thiadiazoles / Q000494:pharmacology
chemical_list: D003499:Cyclic S-Oxides; C523799:MRK 003; D051880:Receptors, Notch; D013830:Thiadiazoles; D018698:Glutamic Acid; D005972:Glutaminase
keywords: GBM; GSI; MRK003; Notch; WNT; glioma; glutamate; glutaminase; glycolysis; metabolism