Figure 5.

 Effect of SU9516 on the sensitivity of Jurkat cells to methotrexate (MTX). (a) Cells were treated with dimethyl sulfoxide (DMSO) or SU9516 (2 μM) for 24 h. Then the cells were cultured with the indicated concentrations of MTX, and subjected to a colony formation assay. The data are presented as a percentage compared to the control with vehicle only, and the bars show SDs (*P < 0.05, **P < 0.01). (b) Whole‐cell extracts from CCRF‐CEM cells treated with the indicated concentrations of SU9516 or DMSO for 24 h were subjected to a Western blot analysis using DHFR, phosphorylated pRB (Ser⁷⁸⁰), and GAPDH antibodies. (c) CCRF‐CEM cells were treated with DMSO or SU9516 (5 μM) for 24 h. Then the cells were cultured with the indicated concentrations of MTX, and subjected to a colony formation assay. The data are presented as a percentage compared to the control with phosphate‐buffered saline (PBS), and the bars show SDs (*P < 0.05, **P < 0.01). (d) Whole‐cell extracts from K562 cells treated with the indicated concentrations of SU9516 or DMSO for 24 h were subjected to a Western blot analysis using DHFR, phosphorylated pRB (Ser⁷⁸⁰) and GAPDH antibodies. (e) K562 cells were treated with DMSO or SU9516 (5 μM) for 24 h. Then the cells were cultured with the indicated concentrations of MTX, and subjected to a colony formation assay. The data are presented as a percentage compared to the control with PBS, and the bars show SDs (*P < 0.05, **P < 0.01).