Effect of Src-kinase inhibitors on NPM-ALK–mediated IL3-independent proliferation of the Ba/F3 cell line. (A) Ba/F3 N/A cells were deprived of serum for 24 hours followed by 6-hour serum readdition in the presence or absence of 10 μM PP1, as indicated. Cell lysates (5 × 105 cells) were subjected to immunoblot analysis with either antiphosphotyrosine 4G10 antibody (upper panel) or ALKc antibody (lower panel). (B) Wild-type Ba/F3 cells (WT) and Ba/F3 cells expressing NPM-ALK (Ba/F3 N/A) were seeded at 2 × 103 cells per well in a 96-well plate in medium enriched with (left) or deprived of (right) IL3. Cells were grown in the absence or in the presence of either 10 μM PP1 or 2 μM SU6656 as indicated. Cell proliferation was determined each day for 6 days using an MTT proliferation assay. Reported results are mean ± SEM of 3 independent experiments performed in triplicate.
