Figure 7.

Knockdown of p21^Waf1/CIP1 promotes the cell death response to cisplatin and Twist1 siRNA. (a and b) A549 and H1299 cells were treated with the indicated concentrations of cisplatin for 24 h. (c) A549 and H1299 cells were transfected with control or Twist1 siRNA for 48 h. (d) A549 cells were transfected with control, Twist1 or p21^Waf1/CIP1 siRNA for 24 h, followed by treatment with 6 μM cisplatin for 24 h. The indicated protein and mRNA levels were measured using western blot (a, c and d) and RT-PCR (b and c) analyses. Cell viability was measured with the MTT assay (d). Cell viability of control siRNA (siCTL)-treated group was set at 100%, and survival relative to the siCTL presented. The graph is shown as the mean of each group and error bars reflect S.D. *P<0.05 versus the siTwist1/cisplatin-treated group