Figure 2. Effect of ABC294640, SKi, nutlin or siRNA knock down of SK isoforms on [³H]thymidine incorporation in androgen-independent LNCaP-AI cells.

Androgen-independent LNCaP-AI cells were treated with ABC294640 or SKi or nutlin for 24 h or scrambled siRNA or SK1 siRNA or SK2 siRNA for 48 h. (A) Concentration-dependent inhibition of DNA synthesis is induced by ABC294640 or SKi. Results are expressed as means +/− SD for n = 3 experiments; (B) Western blot showing the effect of SK1 siRNA or SK2 siRNA on SK1a, p53 and p21 expression. SKi (10 μM) was used a positive control. Actin was used a protein loading control. Blots are representative of three independent experiments. Also shown are bar graphs of the quantification of the effect of SK1 siRNA or SK2 siRNA on SK1a, p53 and p21 expression. Results are expressed as means +/− SD for n = 3 experiments. ***p < 0.001 versus scrambled siRNA. The effect of SK1 siRNA or SK2 siRNA on DNA synthesis is also shown. **p < 0.01 versus scrambled siRNA; (C) Concentration-dependent inhibition of DNA synthesis is induced by nutlin. Results are expressed as means +/− SD for n = 3 experiments.