Title: Multidrug resistance protein (MRP) 1 and MRP3 attenuate cytotoxic and transactivating effects of the cyclopentenone prostaglandin, 15-deoxy-Delta(12,14)prostaglandin J2 in MCF7 breast cancer cells.
Authors: Paumi, Christian M; Wright, Marcus; Townsend, Alan J; Morrow, Charles S
Published In Biochemistry, (2003 May 13)
Abstract: One of the most potent cyclopentenone prostaglandins, 15-deoxy-Delta(12,14)prostaglandin J(2) (15-d-PGJ(2)), has been shown to be cytotoxic in some tumor cells and, as a ligand of peroxisome proliferator activated receptor gamma (PPARgamma), to influence the transcriptional regulation of several genes. We examined whether a glutathione conjugate of 15-d-PGJ(2), 15-d-PGJ(2)-SG, is formed and if the glutathione conjugate efflux pumps, MRP1 and MRP3, could transport this conjugate, thereby attenuating the cytotoxicity and transactivating activity of 15-d-PGJ(2) in MCF7 breast cancer cells. Formation of 15-d-PGJ(2)-SG was demonstrated both in vitro and in cells, and its structure was determined by ESI/MS and NMR. Expression of MRP1 and MRP3 was achieved by stable transduction of parental MCF7 cells. Membrane vesicles derived from these cells supported efficient, ATP-dependent transport of 15-d-PGJ(2)-SG (K(M) 1.4 and 2.9 microM for MRP1 and MRP3, respectively). When compared with parental, MRP-minus MCF7 cells, expression of MRP1 and MRP3 conferred approximately 2-fold protection from 15-d-PGJ(2) cytotoxicity. 15-d-PGJ(2)-mediated transcriptional activation was evaluated in cells transiently transfected with a reporter gene under the transcriptional control of a PPAR responsive element. Treatment of parental MCF7 cells with 15-d-PGJ(2) resulted in a time-dependent induction of reporter gene activity-induction that was measurable with concentrations of added 15-d-PGJ(2) as low as 100 nM. In contrast, expression of MRP1 or MRP3 abolished 15-d-PGJ(2)-dependent reporter gene induction. Depletion of intracellular glutathione reversed MRP1- and MRP3-mediated attenuation of 15-d-PGJ(2) cytotoxicity and transactivation. These data indicate that MRP1 and MRP3 can modulate the biological effects of 15-d-PGJ(2), and likely other cyclopentenone prostaglandins, in a glutathione-dependent manner. The results are consistent with a mechanism for the attenuation of the biological activities of 15-d-PGJ(2) that involves the formation and active efflux of its glutathione conjugate, 15-d-PGJ(2)-SG.
PubMed ID: 12731885
MeSH Terms: ATP-Binding Cassette, Sub-Family B, Member 1/physiology*; Adenosine Triphosphate/metabolism; Biological Transport; Breast Neoplasms/metabolism*; Breast Neoplasms/pathology; Cell Membrane/chemistry; Cell Membrane/metabolism; Cell Survival; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic/drug effects; Glutathione/analogs & derivatives; Glutathione/metabolism; Humans; Immunologic Factors/metabolism*; Immunologic Factors/pharmacology; Inhibitory Concentration 50; Kinetics; Luciferases/metabolism; Magnetic Resonance Spectroscopy; Methotrexate/pharmacology; Multidrug Resistance-Associated Proteins/physiology*; Prostaglandin D2/analogs & derivatives; Prostaglandin D2/metabolism*; Prostaglandin D2/pharmacology; Receptors, Cytoplasmic and Nuclear/metabolism; Spectrometry, Mass, Electrospray Ionization; Transcription Factors/metabolism; Transcriptional Activation*; Transfection; Tumor Cells, Cultured