title: Global metabolic profile identifies choline kinase alpha as a key regulator of glutathione-dependent antioxidant cell defense in ovarian carcinoma.
abstract: Epithelial Ovarian Cancer (EOC) "cholinic phenotype", characterized by increased intracellular phosphocholine content sustained by over-expression/activity of choline kinase-alpha (ChoKα/CHKA), is a metabolic cellular reprogramming involved in chemoresistance with still unknown mechanisms.By stable CHKA silencing and global metabolic profiling here we demonstrate that CHKA knockdown hampers growth capability of EOC cell lines both in vitro and in xenotransplant in vivo models. It also affected antioxidant cellular defenses, decreasing glutathione and cysteine content while increasing intracellular levels of reactive oxygen species, overall sensitizing EOC cells to current chemotherapeutic regimens. Natural recovering of ChoKα expression after its transient silencing rescued the wild-type phenotype, restoring intracellular glutathione content and drug resistance. Rescue and phenocopy of siCHKA-related effects were also obtained by artificial modulation of glutathione levels. The direct relationship among CHKA expression, glutathione intracellular content and drug sensitivity was overall demonstrated in six different EOC cell lines but notably, siCHKA did not affect growth capability, glutathione metabolism and/or drug sensitivity of non-tumoral immortalized ovarian cells. The "cholinic phenotype", by recapitulating EOC addiction to glutathione content for the maintenance of the antioxidant defense, can be therefore considered a unique feature of cancer cells and a suitable target to improve chemotherapeutics efficacy.
authors: Unit of Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: Anna
authors: A
authors: Granata
authors: Unit of Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: Roberta
authors: R
authors: Nicoletti
authors: Molecular Pharmacology, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: Paola
authors: P
authors: Perego
authors: Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
authors: Egidio
authors: E
authors: Iorio
authors: Division of Cancer Imaging Research, In Vivo Cellular and Molecular Imaging Center, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Balaji
authors: B
authors: Krishnamachary
authors: Division of Oncology, Urological Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy.
authors: Fabio
authors: F
authors: Benigni
authors: Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
authors: Alessandro
authors: A
authors: Ricci
authors: Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
authors: Franca
authors: F
authors: Podo
authors: Division of Cancer Imaging Research, In Vivo Cellular and Molecular Imaging Center, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Zaver M
authors: ZM
authors: Bhujwalla
authors: Unit of Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: Silvana
authors: S
authors: Canevari
authors: Unit of Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: Marina
authors: M
authors: Bagnoli
authors: Unit of Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors: Delia
authors: D
authors: Mezzanzanica
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002277:Carcinoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000628:therapy; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002797:Choline Kinase / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D055785:Gene Knockdown Techniques; D005838:Genotype; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D055432:Metabolomics / Q000379:methods; D008819:Mice, Nude; D010051:Ovarian Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000628:therapy; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010641:Phenotype; D034622:RNA Interference; D000067492:RNAi Therapeutics; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D047368:Tumor Burden; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D014408:Biomarkers, Tumor; D017382:Reactive Oxygen Species; C517212:CHKA protein, human; D002797:Choline Kinase; D005978:Glutathione
keywords: choline kinase; glutathione; ovarian cancer; phosphocholine metabolism; reversal of drug resistance