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.
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.
Department of Biochemistry, Wake Forest University School of Medicine, Winton-Salem, North Carolina 27157, USA.
Christian M
CM
Paumi
Marcus
M
Wright
Alan J
AJ
Townsend
Charles S
CS
Morrow
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D001692:Biological Transport; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D002470:Cell Survival; D019008:Drug Resistance, Neoplasm; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D007155:Immunologic Factors / Q000378:metabolism* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008156:Luciferases / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008727:Methotrexate / Q000494:pharmacology; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000502:physiology*; D015230:Prostaglandin D2 / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000255:Adenosine Triphosphate; D005978:Glutathione; D007155:Immunologic Factors; D008156:Luciferases; D008727:Methotrexate; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015230:Prostaglandin D2; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; C097240:15-deoxy-delta(12,14)-prostaglandin J2; C114462:multidrug resistance-associated protein 3