STI571 completely inhibits Bcr-Abl autophosphorylation and leads to a growth factor-dependent proliferation of Bcr-Abl+ cells.
(A) Immunoprecipitation of tyrosine phosphorylated proteins in Bcr-Abl–expressing BaF3p185 cells with (first lanes) or without STI571+IL-3 (second lanes). Precipitates (left panel) or complete lysates (right panel) were separated in a 7.5% SDS-polyacrylamide gel electrophoresis. Immunoblot was performed by using a monoclonal Abl antibody. (B) Cells were plated into 96-well plates at 1 × 104/well. The viable cells in each well were assayed to their ability to transform MTT into a purple formazan. The absorbance of the samples was measured in an ELISA immunosorbent assay reader at 570 nm. Data shown are representative for 3 independent examinations. Values are means ± SD of triplicates.
