Figure 3. H₂O₂ mediated p21^Cip1 and G₂/M phase arrest is attenuated by p21^Cip1 siRNA

HLE B-3 cells were transfected with 100 nM of p21^Cip1 siRNA. After 24 h, the cells were incubated in the absence or presence of 200 μM H₂O₂ for an additional 24 h, collected, and subjected to both western blot analysis (A) and FACS analysis (B) to confirm the attenuation of p21^Cip1 and cell cycle arrest, respectively. The graph shown in A represented the quantification of p21^Cip1 expression (performed by scanning densitometry). The bars shown (A, lower) represent the means±SE of three independent expressions and are expressed as the fold induction above control (unstimulated) values.