Roscovitine synergizes with conventional chemo-therapeutic drugs to induce efficient apoptosis of human colorectal cancer cells

Figure 2 Potentiation of anticancer effect of taxol on human colorectal cancer cell lines by combination with cyclin dependent kinase inhibitor roscovitine. A: Human colorectal cancer cell lines were treated with taxol (10^-11-10^-6 mol/L), or the combination of taxol (10^-11-10^-6 mol/L) and Rosco (5 μg/mL or 10 μg/mL) for 96 h. At the end of treatment, control and drug treated cells were scored for proliferation using the MTT assay; B: Cell cycle phase distribution of human colorectal cancer cells (SW837, 5 × 10⁵ cells/well) treated with taxol (12 × 10^-8 mol/L, 72 h); Rosco (15 μg/mL, 72 h); sequential combination: taxol (12 × 10^-8 mol/L, 24 h) followed by Rosco (15 μg/mL, 48 h); inverted sequential combination: Rosco (15 μg/mL, 24 h) followed by taxol (12 × 10^-8 mol/L, 48 h) and simultaneous combination: taxol plus Rosco (12 × 10^-8 mol/L, 15 μg/mL, 72 h) was evaluated by flow cytometry. The percentage of cells in different phases of the cycle was calculated by cell cycle analysis software, Multicycle (Phoenix Flow System, San Diego CA, USA); C: Human colorectal cancer cells, SW1116 and SW837 (5 × 10⁵ cells/well), were treated with taxol (12 × 10^-8 mol/L), Rosco (15 μg/mL), and the combination of taxol plus Rosco (12 × 10^-8 mol/L + 15 μg/mL) for 72 h. DNA fragments were extracted and analyzed on 1% agrose gel.