Doxorubicin Differentially Induces Apoptosis, Expression of Mitochondrial Apoptosis-Related Genes, and Mitochondrial Potential in BCR-ABL1-Expressing Cells Sensitive and Resistant to Imatinib

Figure 4

Apoptosis in mouse-derived 32D BCR-ABL1+ cells sensitive to imatinib (S) and cells with imatinib resistance caused by the Y253H mutation in the BCR-ABL1 gene (253) or acquired imatinib resistance (AR). The cells were exposed at 37°C for 24 h to doxorubicin (DOX) at 1 µM. Apoptosis was evaluated by flow cytometry with annexin V APC and SYTOX Green dyes. Apoptotic index was calculated as the percentage of apoptotic cells in 5 × 10⁴ cells measured in each of three independent experiments. The dot plots show results of one representative experiment for each kind of cells treated with DOX. The number in the corner of Q3 quadrant presents a fraction of early and late apoptotic cells. The activity of caspases 3 and 7 was determined fluorometrically with CellEvent Caspase-3/7 Green Detection Reagent and presented in relative fluorescent units (RFU). < 0.05 and < 0.001 as compared with imatinib-sensitive cells.