FIG. 7.

Loss of Snk/Plk2 leads to apoptosis during mitosis after treatment with antimicrotubule agents. (a) U2OS cells were transfected with control siRNA duplex or Snk/Plk2 siRNA duplex (300 nmol). Twenty-four hours after transfection, cells were treated with 1 μM paclitaxel. After a 24-h treatment, cells were harvested and stained for active caspase 3. Cells were also stained with propidium iodide to measure DNA content. The upper panel depicts active caspase 3 staining, while in the lower panel, DNA content of active caspase 3-positive cells was determined. (b) U2OS cells were transfected with control siRNA duplex or Snk/Plk2 siRNA duplex (300 nmol). Twenty-four hours after transfection, cells were treated with 1 μM paclitaxel. After 20 h of treatment, cells were harvested and stained for active caspase 3 and cyclin B. Cells were also stained with propidium iodide to measure DNA content. Depicted in the chart is the change in mitotic apoptosis (active caspase 3 positive, cyclin B positive, 4N DNA content) after paclitaxel treatment and siRNA directed against luciferase or Snk/Plk2. Changes are relative to untreated control siRNA. Depicted in the chart is one of several experiments, each performed in triplicate.