Figure 4

Effect of the inhibition of caspase-2 expression on the growth and survival of SK-BR-3 and MCF-7 cells after paclitaxel and SB-T-1216 treatment. (A) Efficiency of caspase-2 suppression by two employed specific siRNAs, i.e. A and B, in SK-BR-3 and MCF-7 cells is shown. Levels of procaspase-2 were determined using western blot analysis and relevant antibodies (see “Materials and Methods”). Actin levels were used to confirm equal protein loading. (B) Effect of nonsense siRNA and specific caspase-2 siRNA on the growth and survival of SK-BR-3 and MCF-7 cells without taxane treatment is also shown. (C) The effect of specific caspase-2 siRNA on the growth and survival of SK-BR-3 and MCF-7 cells after taxane (T) treatment (100 nM for SK-BR-3 cells and 300 nM for MCF-7 cells) is presented. The cells were seeded at 7 × 10³ cells/200 μl of medium per well and prepared as described (see “Materials and Methods”). After 0, 48 and 96 h of incubation, the number of living cells was determined (see “Materials and Methods”). Each column represents the mean of 4 separate cultures ± SEM. *P < 0.05, **P < 0.01 when comparing the effect.