Effect of Bcr-Abl on regulation of the cyclin-dependent kinase inhibitors p21^Waf1/Cip1 and p27^Kip1.

Bcr-Abl disturbs regulation of the cyclin-dependent kinase inhibitors p21^Waf1/Cip1 and p27^Kip1. (A) The 32Dcl3 cells and cells of a representative clone of 32D_Bcr-Ablwt were stimulated with rhG-CSF (left panel). Lysis of the individual cell types was performed at day 0 (prior to G-CSF stimulation) to day 3. In addition, aliquots of 32D_Bcr-Ablwt cells were grown in the presence of rhG-CSF and 1 μM imatinib mesylate. Lysates of such cells were compared with lysates of G-CSF–treated 32D_Bcr-Ablwt cells grown in the absence of imatinib mesylate (right panel). Western blot analysis of the different lysates was performed with the use of antibodies to p27^Kip1, and p21^Waf1/Cip1. Equal protein loading onto individual lanes was controlled by blotting the stripped membrane with anti–β-tubuline ab. (B) Confocal immunofluorescence microscopy of 32Dcl3 and 32D_Bcr-Ablwt cells for p21^Waf1/Cip1. Representative pictures for each cell type are shown. Scale bar measurements, top row, 4.00 μm; bottom row, 8.00 μm.