Apoptosis is not specifically induced in CML CD34⁺ cells in response to imatinib mesylate exposure.

CML and normal CD34⁺ cells were exposed to imatinib mesylate (0-5 μM) for 96 hours. Apoptosis was analyzed by flow cytometry as the percentage of cells positively labeled by annexin V–FITC and negative for 7-AAD. The percentage of apoptotic cells is plotted as a function of the concentration of imatinib mesylate for CML (—▾—) and normal (- - ♦ - -) samples. Data shown are the mean ± SEM values for replicate experiments (CML, n = 6; and normal, n = 3). Significant increases in the percentage of apoptotic cells on exposure to imatinib mesylate are indicated with asterisks (2 asterisks, P < .01; and 1 asterisk,P < .05).