Tumor cell responses to a novel glutathione S-transferase-activated nitric oxide-releasing prodrug

Mol Pharmacol. 2004 May;65(5):1070-9. doi: 10.1124/mol.65.5.1070.

Abstract

We have used structure-based design techniques to introduce the drug O(2)-[2,4-dinitro-5-(N-methyl-N-4-carboxyphenylamino) phenyl] 1-N,N-dimethylamino)diazen-1-ium-1,2-diolate (PABA/NO), which is efficiently metabolized to potentially cytolytic nitric oxide by the pi isoform of glutathione S-transferase, an enzyme expressed at high levels in many tumors. We have used mouse embryo fibroblasts (MEFs) null for GSTpi (GSTpi(-/-)) to show that the absence of GSTpi results in a decreased sensitivity to PABA/NO. Cytotoxicity of PABA/NO was also examined in a mouse skin fibroblast (NIH3T3) cell line that was stably transfected with GSTpi and/or various combinations of gamma-glutamyl cysteine synthetase and the ATP-binding cassette transporter MRP1. Overexpression of MRP1 conferred the most significant degree of resistance, and in vitro transport studies confirmed that a GSTpi-activated metabolite of PABA/NO was effluxed by MRP1 in a GSH-dependent manner. Additional studies showed that in the absence of MRP1, PABA/NO activated the extracellular-regulated and stress-activated protein kinases ERK, c-Jun NH(2)-terminal kinase (JNK), and p38. Selective inhibition studies showed that the activation of JNK and p38 were critical to the cytotoxic effects of PABA/NO. Finally, PABA/NO produced antitumor effects in a human ovarian cancer model grown in SCID mice.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3T3 Cells
  • 4-Aminobenzoic Acid / chemical synthesis
  • 4-Aminobenzoic Acid / chemistry
  • 4-Aminobenzoic Acid / pharmacology*
  • Animals
  • Azo Compounds / chemical synthesis
  • Azo Compounds / chemistry
  • Azo Compounds / pharmacology*
  • Cell Division / drug effects
  • Enzyme Activation / drug effects
  • Glutathione S-Transferase pi
  • Glutathione Transferase / metabolism*
  • Isoenzymes / metabolism*
  • JNK Mitogen-Activated Protein Kinases
  • Leukotriene C4 / metabolism
  • Mice
  • Mice, SCID
  • Mitogen-Activated Protein Kinases / metabolism
  • Multidrug Resistance-Associated Proteins / metabolism
  • Nitric Oxide / metabolism*
  • Nitric Oxide Donors / pharmacology*
  • Piperazines / pharmacology
  • Prodrugs / pharmacology*
  • Tumor Cells, Cultured
  • p38 Mitogen-Activated Protein Kinases
  • para-Aminobenzoates

Substances

  • Azo Compounds
  • Isoenzymes
  • Multidrug Resistance-Associated Proteins
  • Nitric Oxide Donors
  • O(2)-(2,4-dinitro-5-(N-methyl-N-4-carboxyphenylamino)phenyl 1-N,N-dimethylamino)diazen-1-ium-1,2-diolate
  • O(2)-(2,4-dinitrophenyl) 1-((4-ethoxycarbonyl)piperazin-1-yl)diazen-1-ium-1,2-diolate
  • Piperazines
  • Prodrugs
  • para-Aminobenzoates
  • Leukotriene C4
  • Nitric Oxide
  • Glutathione S-Transferase pi
  • Glutathione Transferase
  • Gstp1 protein, mouse
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • 4-Aminobenzoic Acid