Abstract
Transfection 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
Original language | English |
---|---|
Pages (from-to) | 2532-2535 |
Number of pages | 4 |
Journal | Cancer research |
Volume | 59 |
Issue number | 11 |
Publication status | Published - 1 Jun 1999 |
Keywords
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B/antagonists & inhibitors
- ATP-Binding Cassette Transporters/antagonists & inhibitors
- Adenosine Triphosphate/metabolism
- Antimetabolites, Antineoplastic/metabolism
- Drug Resistance, Multiple/genetics
- Drug Resistance, Neoplasm/genetics
- Female
- Folic Acid Antagonists/metabolism
- Glutamates/metabolism
- Humans
- Indoles/metabolism
- Isoindoles
- Methotrexate/metabolism
- Ovarian Neoplasms/genetics
- Quinazolines/metabolism
- Thiophenes/metabolism
- Transfection
- Tumor Cells, Cultured/drug effects