BEL-7402 cells were transfected with scramble siRNA, Numb siRNA, respectively. 48 h after transfection, the amount of Numb and p21 was determined by antibodies specific for Numb and p21(C). (A)Cell cycle was analysed by FACSCalibur (Becton Dickinson, Mountain View, CA). The proliferative index (PIx) decreased compared to control (P<0.05, B) For BrdU incorporation analysis, the cells were incubated with a mouse monoclonal anti-BrdU antibody overnight at 4°C,and were incubated with fluorescein isothiocyanate-conjugated goat antimouse IgG for 1 h at room temperature. Hoechst 33342 was used to label nuclei (red). Photographs were taken using a Nikon microscope. Magnification100x. The proliferation cells (red) decreased significantly.