Effect of Bcr-Abl on G-CSF–induced regulation of C/EBPα, C/EBPε, c-Myc, and PU.1.

Bcr-Abl disturbs G-CSF–induced regulation of C/EBPα, C/EBPε, and c-Myc, but not PU.1. The 32Dcl3 cells and a representative clone of 32D_Bcr-Ablwt cells were grown in the presence of rhG-CSF (left panel). Lysates of the individual cell types were obtained at day 0 (prior to G-CSF stimulation grown in IL-3) to day 3 and subjected to Western blot analysis by means of rabbit polyclonal antibodies to C/EBPα, C/EBPε, PU.1, G-CSFR, and c-Myc. In addition, aliquots of 32D_Bcr-Ablwt cells were grown in the presence of rhG-CSF and 1 μM imatinib mesylate (right panel). Lysates were obtained at day 0 (prior to G-CSF stimulation) to day 3; subjected to Western blot analysis by means of rabbit polyclonal antibodies to C/EBPα, C/EBPε, G-CSFR, and c-Myc; and compared with lysates of G-CSF–treated 32D_Bcr-Ablwt cells grown in the absence of imatinib mesylate. Importantly, lysates of left and right panels are matched; that is, they are from the same subclone and experiments were done at the same time.