Predominance of functional multidrug resistance (MDR-1) phenotype in CD34+ acute myeloid leukemia cells

• Published in: Blood 1993-11, Vol.82 (10), p.3157-3162
• Main Authors: TE BOEKHORST, P. A. W, DE LEEUW, K, SCHOESTER, M, WITTEBOL, S, NOOTER, K, HAGEMAIJER, A, LÖWENBERG, B, SONNEVELD, P
• Format: Article
• Language: English
• Subjects: Antigens, CD - analysis; Antigens, CD34; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; ATP Binding Cassette Transporter, Subfamily B, Member 1; Biological and medical sciences; Carrier Proteins - analysis; Daunorubicin - administration & dosage; Daunorubicin - metabolism; Drug Resistance; Flow Cytometry; Hematologic and hematopoietic diseases; Humans; Leukemia, Myeloid, Acute - drug therapy; Leukemia, Myeloid, Acute - immunology; Leukemia, Myeloid, Acute - metabolism; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Medical sciences; Membrane Glycoproteins - analysis; Phenotype
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V82.10.3157.3157

The expression of the MDR-1-encoded P-170 glycoprotein (P-170) associated with clinical multidrug resistance (MDR) was investigated in 52 consecutive patients with untreated acute myeloid leukemia (AML). P-170 expression was analyzed in correlation with CD34 expression and clinical response. Thirty of 52 patients expressed P-170 (58%). Eight of 30 P-170+ as compared with 16 of 22 P-170- patients achieved a complete remission (CR) (27% v 73%, P = .003). In 21 of 30 P-170+ patients, expression of the CD34 antigen was observed in greater than 10% of the blast cells, as compared with 14 of 22 P-170- patients (70% v 64%, P > .05). The CR rate of CD34+ and CD34- patients was 31% and 76%, respectively (P = .006). In AMLs that simultaneously expressed both P-170 and CD34, the CR rate was worse as compared with those negative for P-170 and CD34 (5% v 63%, P = .004). In 12 patients (8 P-170+, 4 P-170-) CD34 and P-170 expression were further characterized by double fluorescence studies. It was shown that P-170+ cells were largely, but not exclusively, restricted to the CD34+ cell population. For the 8 P-170+ AML samples, the median ratio of P-170+/P-170- in CD34+ cells was 4.845 (range, 0.60 to 25.00) as compared with 0.135 (range, 0.02 to 0.67) in CD34- cells. In these 12 AML samples, the presence of functional resistance as defined by reduced daunorubicin accumulation was evaluated in CD34+ and CD34- AML cells. In 8 of 8 P-170+ patients, intracellular daunorubicin accumulation in CD34+ AML blast cells was lower than in CD34- cells, and it increased after cyclosporin addition. No difference of intracellular daunorubicin accumulation was observed between CD34+ and CD34- AML cells of 4 P-170- patients. These data indicate that P-170 expression in AML with a heterogeneous CD34+ phenotype seems predominantly present in CD34+ AML blast cells.