RETRACTED: ATP-dependent uptake of natural product cytotoxic drugs by membrane vesicles establishes MRP as a broad specificity transporter.
- 9 July 1996
- journal article
- retracted article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 93 (14) , 6929-6934
- https://doi.org/10.1073/pnas.93.14.6929
Abstract
MRP is a recently isolated ATP-binding cassette family transporter. We previously reported transfection studies that established that MRP confers multidrug resistance [Kruh, G. D., Chan, A., Myers, K., Gaughan, K., Miki, T. & Aaronson, S. A. (1994) Cancer Res. 54, 1649-1652] and that expression of MRP is associated with enhanced cellular efflux of lipophilic cytotoxic agents [Breuninger, L. M., Paul, S., Gaughan, K., Miki, T., Chan, A., Aaronson, S. A. & Kruh, G. D. (1995) Cancer Res. 55, 5342-5347]. To examine the biochemical mechanism by which MRP confers multidrug resistance, drug uptake experiments were performed using inside-out membrane vesicles prepared from NIH 3T3 cells transfected with an MRP expression vector. ATP-dependent transport was observed for several lipophilic cytotoxic agents including daunorubicin, etoposide, and vincristine, as well as for the glutathione conjugate leukotriene C4 (LTC4). However, only marginally increased uptake was observed for vinblastine and Taxol. Drug uptake was osmotically sensitive and saturable with regard to substrate concentration, with Km values of 6.3 microM, 4.4 microM, 4.2 microM, 35 nM, and 38 microM, for daunorubicin, etoposide, vincristine, LTC4, and ATP, respectively. The broad substrate specificity of MRP was confirmed by the observation that daunorubicin transport was competitively inhibited by reduced and oxidized glutathione, the glutathione conjugates S-(p-azidophenacyl)-glutathione (APA-SG) and S-(2,4-dinitrophenyl)glutathione (DNP-SG), arsenate, and the LTD4 antagonist MK571. This study establishes that MRP pumps unaltered lipophilic cytotoxic drugs, and suggests that this activity is an important mechanism by which the transporter confers multidrug resistance. The present study also indicates that the substrate specificity of MRP is overlapping but distinct from that of P-glycoprotein, and includes both the neutral or mildly cationic natural product cytotoxic drugs and the anionic products of glutathione conjugation. The widespread expression of MRP in tissues, combined with its ability to transport both lipophilic xenobiotics and the products of phase II detoxification, indicates that the transporter represents a widespread and remarkably versatile cellular defense mechanism.Keywords
This publication has 45 references indexed in Scilit:
- Cellular and in Vitro Transport of Glutathione Conjugates by MRPBiochemistry, 1996
- How Does the MRP/GS-X Pump Export Doxorubicin?JNCI Journal of the National Cancer Institute, 1995
- Expression Pattern of MRP in Human Tissues and Adult Solid Tumor Cell LinesJNCI Journal of the National Cancer Institute, 1995
- The Leukotriene LTD4 Receptor Antagonist Mk571 Specifically Modulates MRP Associated Multidrug ResistanceBiochemical and Biophysical Research Communications, 1995
- Monoclonal Antibodies against HIV Type 1 Integrase: Clues to Molecular StructureAIDS Research and Human Retroviruses, 1994
- Characterization of the ATP‐dependent leukotriene C4 export carrier in mastocytoma cellsEuropean Journal of Biochemistry, 1994
- Chemosensitisation and drug accumulation effects of cyclosporin A, PSC-833 and verapamil in human MDR large cell lung cancer cells expressing a 190k membrane protein distinct from P-glycoproteinEuropean Journal Of Cancer, 1993
- BIOCHEMISTRY OF MULTIDRUG RESISTANCE MEDIATED BY THE MULTIDRUG TRANSPORTERAnnual Review of Biochemistry, 1993
- Overexpression of a Transporter Gene in a Multidrug-Resistant Human Lung Cancer Cell LineScience, 1992
- ATP and GTP as alternative energy sources for vinblastine transport by P‐170 in KB‐V1 plasma membrane vesiclesFEBS Letters, 1992