The development of drug resistance in leukemia cells constitutes the major reason for treatment failure in acute myeloid leukemia (AML). Although a number of prognostic factors such as cellular morphology and cytogenetic abnormalities have been identified, the mechanisms by which cellular resistance to chemotherapy occurs are poorly understood. We propose to build upon observations derived from our physiologic or """"""""functional"""""""" assays for a multidrug resistance (MDR) phenotype which reveal that daunorubicin accumulation, retention and cytotoxicity can be enhanced by cyclosporin A (CsA) or verapamil in blast cells from more than half of newly diagnosed AML patients. The major thrust will be the correlation of our """"""""functional"""""""" evidence for MDR with expression of P-glycoprotein (Pgp) or mdr1 transcripts. In addition, we will also study multidrug resistance-associated protein (MRP) a newly discovered and cloned membrane protein associated with drug resistance in human neoplastic cell lines. MRP has been found to be overexpressed in the human leukemia cell line HL- 60/Adr, which displays a classical MDR phenotype and impaired accumulation and retention of drug, but does not overexpress Pgp. Flow cytometry and reverse transcriptase-PCR (RT-PCR) will be utilized to identify Pgp expression in leukemic cells, using different approaches than in our previous proposal. MRP expression will be determined by RT-PCR. To validate these assays, these data will be correlated with our """"""""functional"""""""" assays for an MDR phenotype, and also with outcome after treatment and clinical parameters, in a consecutive cohort of newly diagnosed patients treated on clinical trials, as well as with data and samples acquired during the previous granting period. Serial evaluations will be done at the time of treatment failure or relapse. Finally, we will also initiate a phase I trial of CsA, a modulator of Pgp-associated MDR, in combination with daunorubicin, etoposide and cytarabine, which is a regimen that could be used as initial induction therapy for AML. The UMCC has a large population of leukemia patients, extensive preliminary data on the proposed projects, a history of productive clinical-laboratory interactions and represents an excellent environment in which to study these important questions.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA052178-06
Application #
2007835
Study Section
Experimental Therapeutics Subcommittee 1 (ET)
Program Officer
Wu, Roy S
Project Start
1990-05-01
Project End
1999-11-30
Budget Start
1996-12-01
Budget End
1999-11-30
Support Year
6
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Maryland Baltimore
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
003255213
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Natarajan, Karthika; Xie, Yi; Baer, Maria R et al. (2012) Role of breast cancer resistance protein (BCRP/ABCG2) in cancer drug resistance. Biochem Pharmacol 83:1084-103
Bauer, Kenneth S; Karp, Judith E; Garimella, Tushar S et al. (2005) A phase I and pharmacologic study of idarubicin, cytarabine, etoposide, and the multidrug resistance protein (MDR1/Pgp) inhibitor PSC-833 in patients with refractory leukemia. Leuk Res 29:263-71
Ross, D D; Karp, J E; Chen, T T et al. (2000) Expression of breast cancer resistance protein in blast cells from patients with acute leukemia. Blood 96:365-8
Ross, D D; Yang, W; Abruzzo, L V et al. (1999) Atypical multidrug resistance: breast cancer resistance protein messenger RNA expression in mitoxantrone-selected cell lines. J Natl Cancer Inst 91:429-33
Doyle, L A; Yang, W; Abruzzo, L V et al. (1998) A multidrug resistance transporter from human MCF-7 breast cancer cells. Proc Natl Acad Sci U S A 95:15665-70
Ross, D D; Gao, Y; Yang, W et al. (1997) The 95-kilodalton membrane glycoprotein overexpressed in novel multidrug-resistant breast cancer cells is NCA, the nonspecific cross-reacting antigen of carcinoembryonic antigen. Cancer Res 57:5460-4
Doyle, L A; Yang, W; Rishi, A K et al. (1996) H19 gene overexpression in atypical multidrug-resistant cells associated with expression of a 95-kilodalton membrane glycoprotein. Cancer Res 56:2904-7
Ross, D D; Doyle, L A; Yang, W et al. (1995) Susceptibility of idarubicin, daunorubicin, and their C-13 alcohol metabolites to transport-mediated multidrug resistance. Biochem Pharmacol 50:1673-83
Doyle, L A; Ross, D D; Sridhara, R et al. (1995) Expression of a 95 kDa membrane protein is associated with low daunorubicin accumulation in leukaemic blast cells. Br J Cancer 71:52-8
Ross, D D; Wooten, P J; Tong, Y et al. (1994) Synergistic reversal of multidrug-resistance phenotype in acute myeloid leukemia cells by cyclosporin A and cremophor EL. Blood 83:1337-47

Showing the most recent 10 out of 12 publications