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.
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Authors | Victoria J Findlay, Danyelle M Townsend, Joseph E Saavedra, Gregory S Buzard, Michael L Citro, Larry K Keefer, Xinhua Ji, Kenneth D Tew |
Journal | Molecular pharmacology
(Mol Pharmacol)
Vol. 65
Issue 5
Pg. 1070-9
(May 2004)
ISSN: 0026-895X [Print] United States |
PMID | 15102935
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- 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
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Topics |
- 3T3 Cells
- 4-Aminobenzoic Acid
(chemical synthesis, chemistry, pharmacology)
- Animals
- Azo Compounds
(chemical synthesis, chemistry, 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
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