Flow cytometric analysis of P-glycoprotein in normal and leukemic cells.
Classical multidrug resistance is characterized by overexpression of a membrane protein, P-glycoprotein, which acts like a drug-extruding pump, reducing accumulation of cytotoxic drugs inside malignant cells. We have developed a simple method for detecting an intracellular epitope of P-glycoprotein in normal and leukemic cells by the monoclonal antibody JSB-1 and fluorescence-activated flow cytometry. Permeabilization of blood and bone marrow cells in unprocessed samples is achieved by a commercially available red blood cell lysing solution which excellently preserves the light scatter properties of leukocytes. The method is suitable for analyzing samples in clinical routine. Lower than 1% reactivity was seen in the lymphoid gate of normal peripheral blood and bone marrow samples as compared with over 60% of reacting cells in some leukemic samples. Twelve patients with acute de novo leukemia were studied at presentation, 13 patients at a refractory stage, and 28 in remission. There was a positive correlation between the P-glycoprotein and the CD34 expression in acute myelogenous leukemia and an association between the P-glycoprotein expression and the blast count in both acute myelogenous and lymphatic leukemias.
Finnish Red Cross, Blood Transfusion Service, Helsinki, Finland.
M I
MI
Tiirikainen
M T
MT
Syrjälä
S E
SE
Jansson
T
T
Krusius
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000911:Antibodies, Monoclonal; D001854:Bone Marrow Cells; D003593:Cytoplasm / Q000737:chemistry; D004351:Drug Resistance; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007938:Leukemia / Q000473:pathology*; D007962:Leukocytes / Q000737:chemistry*; D008562:Membrane Glycoproteins / Q000032:analysis*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000911:Antibodies, Monoclonal; D008562:Membrane Glycoproteins