P-Glycoprotein Expression in Acute Myeloblasts Leukemia Analyzed by Immunocytochemistry and Flow Cytometry

Abstract

Using the APAAP technique, we assessed the reactivity of five monoclonal antibodies, JSB1, C219, Mab 57, 2F8 and MRK16, to gp 170 in 60 cases of de novo acute myeloid leukemia (AML) and 13 relapses. Reactivity, varied between the five antibodies, and positivity was obtained with 2F8 > JSB1 > MRK16 > Mab57 > C219. Sixteen of the 60 cases were also studied by flow cytometry. In 10 cases, the results with the two techniques corresponded, in the other 6 cases, flow cytometry proved more sensitive than APAAP in detecting small amounts of gp170. In the flow cytometry analysis, the cells fixed in methanol and paraformaldehyde were more fluorescent than unfixed samples or those fixed in paraformaldehyde or methanol alone. Our results thus reveal that positivity for gp 170 depends on various factors, including the specificity of the monoclonal antibodies, the techniques used and the preservation of the samples. This suggests the need for a clear standardization of the methods to detect gp170.

Intracellular Accumulation of Nelfinavir and Its Relationship to P-Glycoprotein Expression and Function in HIV-Infected Patients

“…Cells were fixed in 2% paraformaldehyde (Cellfix, Becton Dickinson, Mountain View, Calif., USA), permeabilized with 0.05% saponin (Sigma) and labelled with a JSB1 monoclonal antibody (Sanbio, Uden, the Netherlands) directed towards a highly conserved intracellular epitope of P-gp (30 min at 37°C). JSB1 has been widely validated as a MDR1 P-gp-specific antibody [32][33][34][35]. A monoclonal IE immunoglobulin (Ig)G derived from a murine hybridoma supernatant (ATCC, Manasses, Va., USA) HB179, served as a negative fluorescence control and antibody to the cytoskeletal component vimentin (Dako AS Glostrup, Denmark) was employed as a control for the permeabilization technique.…”

99mTc tetrofosmin scintigraphy in acute leukaemia: the relationship between marrow uptake of tetrofosmin and P-glycoprotein and chemotherapy response

“…Several methods have been established for the determination of MDR1 with the hope of optimizing therapy protocols [6][7][8][9][10]. While some methods (e.g.…”