Figure 3. Effects of genetic or biochemical KIT inhibition on PPY-A sensitivity in normal and CML CD34+ cells.
(A) CD34+ cells from newly diagnosed CML-CP patients (top, n=4) or healthy controls (bottom, n=4) were cultured for 14 days in semisolid medium containing IL-3 and GM-CSF ± SCF. BAW667, PPY-A, BAW667+PPY-A or imatinib were added as indicated. CFU-GM colonies were scored on day 14. Untreated controls (without SCF) were set to 1. Error bars represent SEM; *p<0.05; **p<0.01; ***p<0.001 (Student’s t-test). (B) CD34+ cells from the same patients (top) and controls (bottom) as in (A) were infected with lentivirus for simultaneous expression of GFP and either shKIT or shSCR. Cells were plated in semisolid medium containing IL-3 and GM-CSF. PPY-A, SCF or both were added as indicated. GFP-positive colonies were scored after 14 days. shSCR controls cultured with IL-3 and GM-SCF only were set to 1. Error bars represent SEM; *p<0.05; **p<0.01; ***p<0.001 (Student’s t-test).