J H Hooijberg, H J Broxterman, M Kool, Y G Assaraf, G J Peters, P Noordhuis, R J Scheper, P Borst, H M Pinedo, G Jansen
Department of Medical Oncology, Academisch Ziekenhuis Vrije Universiteit, Amsterdam, The Netherlands.
Cancer research 1999 Jun 1Transfection of multidrug resistance proteins (MRPs) MRP1 and MRP2 in human ovarian carcinoma 2008 cells conferred a marked level of resistance to short-term (1-4 h) exposure to the polyglutamatable antifolates methotrexate (MTX; 21-74-fold), ZD1694 (4-138-fold), and GW1843 (101-156-fold). Evidence for MRP-mediated antifolate efflux relies upon the following findings: (a) a 2-3.3-fold lower accumulation of [3H]MTX and subsequent reduced formation of long-chain polyglutamate forms of MTX; (b) reversal of MTX resistance by probenecid in both transfectants, and (c) ATP-dependent uptake of [3H]MTX in inside-out vesicles of MRP1 and MRP2 transfectants. This report provides a mechanistic basis for resistance to polyglutamatable antifolates through an MRP-mediated drug extrusion.
J H Hooijberg, H J Broxterman, M Kool, Y G Assaraf, G J Peters, P Noordhuis, R J Scheper, P Borst, H M Pinedo, G Jansen. Antifolate resistance mediated by the multidrug resistance proteins MRP1 and MRP2. Cancer research. 1999 Jun 1;59(11):2532-5
PMID: 10363967
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