Figure 4.

Effect of p21 and checkpoint kinase 2 (Chk2) knockdown on resveratrol (RES)-induced S-phase delay. HepG2 cells were transfected with control small interfering RNA (siRNA, p21 siRNA or Chk2 siRNA as described in the Methods section). Twenty-four-hour posttransfection, the transfectants were subsequently treated with 25 or 50 µM of RES for 24 h, and then they were harvested and stained with propidium iodide, followed by flow cytometry analysis. The experiments were repeated twice, and similar observations were made. A representative data set was shown.