Abstract |
A representative cause of multidrug resistance (MDR) is expression of the MDR gene (mdr1) and its product P-glycoprotein (P-gp). The function of P-gp is thought to be the extrusion of anticancer drugs from the cell against a concentration gradient. In acute myelogenous leukemia (AML), P-gp expression in leukemic blast cells at initial presentation has been reported to be 20% to 40%. The remission rate of acute leukemia patients is significantly lower in P-gp+ patients than in P-gp- patients. A significantly shorter survival and relapse-free survival in P-gp+ AML patients compared with P-gp- patients has been reported. Intracellular daunorubicin/Rhodamine123 content in P-gp+ leukemic blast cells is significantly lower than in P-gp- leukemic blast cells. By using a leukemic blast colony assay, lowered sensitivity to the anticancer drug was revealed not only in leukemic blast cells but also in leukemic progenitors. One method to overcome MDR with a possibility of clinical application is to use drugs that interfere with the function of P-gp. The addition of MS-209 in vitro as an MDR-reversing agent significantly enhanced the intracellular daunorubicin/Rhodamine 123 accumulation and the retention of P-gp+ leukemic blast cells to a level similar to that of P-gp- blast cells. Recent clinical trials using MDR-reversing agents have demonstrated some encouraging results in P-gp+ patients but not in P-gp- patients.
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Authors | T Motoji, S Motomura, Y H Wang |
Journal | International journal of hematology
(Int J Hematol)
Vol. 72
Issue 4
Pg. 418-24
(Dec 2000)
ISSN: 0925-5710 [Print] Japan |
PMID | 11197207
(Publication Type: Journal Article, Review)
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Chemical References |
- ATP Binding Cassette Transporter, Subfamily B, Member 1
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Topics |
- ATP Binding Cassette Transporter, Subfamily B, Member 1
(antagonists & inhibitors, genetics, metabolism)
- Clinical Trials as Topic
- Drug Resistance, Multiple
(genetics)
- Drug Resistance, Neoplasm
(genetics)
- Genetic Therapy
- Humans
- Leukemia, Myeloid, Acute
(drug therapy, therapy)
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