Figure 7.

Effects of c-Met inhibitors on growth of CML cells. (A) KU812 cells (left panels) and K562 cells (right panels) were incubated in control medium (CO) or in medium containing various concentrations of the c-Met inhibitors PF-2341066 (upper panels) or SU11274 (lower panels) at 37°C and 5% CO₂ for 48 hours. After incubation, uptake of ³H-thymidine was measured. Results are expressed as the percentage of control (CO) and represent the mean ± SD of three independent experiments. (B) Ficoll-isolated mononuclear BM cells (left panels) and PB cells (right panels) were incubated in control medium (CO) or in medium containing various concentrations of the c-Met inhibitors PF-2341066 (upper panels) or SU11274 (lower panels) at 37°C and 5% CO₂ for 48 hours. After incubation, ³H-thymidine uptake was measured. Results are expressed as percentage of control and represent the mean ± SD of three independent experiments (three patients). (C and D) KU812 cells were incubated in the absence (CO) or presence of various concentrations of the c-Met inhibitor PF-2341066 at 37°C for 24 and 48 hours. After incubation, apoptosis was measured by light microscopy, Annexin V/PI staining, and active caspase 3 staining by flow cytometry. In C, one typical experiment is shown for Annexin V/PI staining (left panel) and active caspase 3 staining (right panel) after 24 hours. In D, results show the percentage of Annexin V/PI-positive cells (upper panels: left panels, 24 hours; right panels, 48 hours), the percentage of active caspase 3-positive cells (middle panels: left panels, 24 hours; right panels, 48 hours), and the numbers of apoptotic cells by light microscopy (lower panels: left panels, 24 hours; right panels, 48 hours). Results represent the mean ± SD of three independent experiments. *P < .05 compared with control (CO). (E) KU812 cells were incubated in control medium (CO) or with the c-Met inhibitors PF-2341066 or SU11274 (each 1 µM) at 37°C for 4 hours. Then, cells were spun on cytospin slides and stained with an antibody against phospho c-Met (magnification, 100x/1.35).