Inhibition of Nicotinamide Phosphoribosyltransferase (NAMPT) Activity by Small Molecule GMX1778 Regulates Reactive Oxygen Species (ROS)-mediated Cytotoxicity in a p53- and Nicotinic Acid Phosphoribosyltransferase1 (NAPRT1)-dependent Manner
Autor: | Naoko Takebe, Stephen S. Yoo, Hongyun Li, David Cerna, Siobhan Flaherty, C. Norman Coleman |
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Rok vydání: | 2012 |
Předmět: |
Niacinamide
Nicotinamide phosphoribosyltransferase Apoptosis Guanidines Biochemistry chemistry.chemical_compound Superoxides Cell Line Tumor Humans Gene Regulation Pentosyltransferases Nicotinamide Phosphoribosyltransferase Molecular Biology chemistry.chemical_classification Reactive oxygen species Cyanides Dose-Response Relationship Drug Nicotinamide biology Superoxide Cell Biology Glutathione Cell biology Gene Expression Regulation Neoplastic chemistry Cancer cell biology.protein Phosphoribosyltransferase NAD+ kinase Tumor Suppressor Protein p53 Reactive Oxygen Species Oxidation-Reduction NADP Intracellular |
Zdroj: | Journal of Biological Chemistry. 287:22408-22417 |
ISSN: | 0021-9258 |
Popis: | Cancer cells undergo mitosis more frequently than normal cells and thus have increased metabolic needs, which in turn lead to higher than normal reactive oxygen species (ROS) production. Higher ROS production increases cancer cell dependence on ROS scavenging systems to balance the increased ROS. Selectively modulating intracellular ROS in cancers by exploiting cancer dependence on ROS scavenging systems provides a useful therapeutic approach. Essential to developing these therapeutic strategies is to maintain physiologically low ROS levels in normal tissues while inducing ROS in cancer cells. GMX1778 is a specific inhibitor of nicotinamide phosphoribosyltransferase, a rate-limiting enzyme required for the regeneration of NAD(+) from nicotinamide. We show that GMX1778 increases intracellular ROS in cancer cells by elevating the superoxide level while decreasing the intracellular NAD(+) level. Notably, GMX1778 treatment does not induce ROS in normal cells. GMX1778-induced ROS can be diminished by adding nicotinic acid (NA) in a NA phosphoribosyltransferase 1 (NAPRT1)-dependent manner, but NAPRT1 is lost in a high frequency of glioblastomas, neuroblastomas, and sarcomas. In NAPRT1-deficient cancer cells, ROS induced by GMX1778 was not susceptible to treatment with NA. GMX1778-mediated ROS induction is p53-dependent, suggesting that the status of both p53 and NAPRT1 might affect tumor apoptosis, as determined by annexin-V staining. However, as determined by colony formation, GMX1778 long term cytotoxicity in cancer cells was only prevented by the addition of NA to NAPRT1-expressing cells. Exposure to GMX1778 may be a novel way of inducing ROS selectively in NAPRT1-negative tumors without inducing cytotoxic ROS in normal tissue. |
Databáze: | OpenAIRE |
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