Identification of the Nicotinamide Salvage Pathway as a New Toxification Route for Antimetabolites

Cell Chem Biol. 2018 Apr 19;25(4):471-482.e7. doi: 10.1016/j.chembiol.2018.01.012. Epub 2018 Feb 22.


Interest in the modulation of nicotinamide adenine dinucleotide (NAD) metabolome is gaining great momentum because of its therapeutic potential in different human disorders. Suppression of nicotinamide salvage by nicotinamide phosphoribosyl transferase (NAMPT) inhibitors, however, gave inconclusive results in neoplastic patients because several metabolic routes circumvent the enzymatic block converging directly on nicotinamide mononucleotide adenylyl transferases (NMNATs) for NAD synthesis. Unfortunately, NMNAT inhibitors have not been identified. Here, we report the identification of Vacor as a substrate metabolized by the consecutive action of NAMPT and NMNAT2 into the NAD analog Vacor adenine dinucleotide (VAD). This leads to inhibition of both enzymes, as well as NAD-dependent dehydrogenases, thereby causing unprecedented rapid NAD depletion, glycolytic block, energy failure, and necrotic death of NMNAT2-proficient cancer cells. Conversely, lack of NMNAT2 expression confers complete resistance to Vacor. Remarkably, Vacor prompts VAD formation and growth suppression in NMNAT2-positive neuroblastoma and melanoma xenografts. Our data show the first evidence of harnessing the entire nicotinamide salvage pathway for antimetabolic strategies.

Keywords: NAD; NAMPT; NMNAT2; Vacor; dehydrogenases; glycolysis; melanoma cells; neuroblastoma cells; xenograft.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimetabolites, Antineoplastic / metabolism
  • Antimetabolites, Antineoplastic / pharmacology*
  • Antimetabolites, Antineoplastic / therapeutic use
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Glycolysis / drug effects
  • Humans
  • Melanoma / drug therapy
  • Melanoma / metabolism
  • Mice, Nude
  • Models, Molecular
  • NAD / metabolism*
  • Neuroblastoma / drug therapy
  • Neuroblastoma / metabolism
  • Niacinamide / metabolism
  • Nicotinamide Phosphoribosyltransferase / antagonists & inhibitors
  • Nicotinamide Phosphoribosyltransferase / metabolism*
  • Phenylurea Compounds / metabolism
  • Phenylurea Compounds / pharmacology*
  • Phenylurea Compounds / therapeutic use


  • Antimetabolites, Antineoplastic
  • Phenylurea Compounds
  • NAD
  • Niacinamide
  • Nicotinamide Phosphoribosyltransferase
  • pyriminil