Figure 4.
Effect of Bmi-1 silencing on cell cycle progression and expression of cyclin D1, p21 of MCF-7 cells. (A) The effect of Bmi-1 silencing on cell cycle progression as shown by FCM. Cells were harvested 48 h after transfection and then stained with propidium iodide (PI). Bmi-1 silencing induced an obvious increase in the number of cells at G0/G1 phase and reduction in S phase; 77.10% of the MCF-7 cells in Bmi-1si were found at G0/G1 phase, compared to 63.75% and 64.84% cells in blank control and GFPsi, respectively. There were significant differences between Bmi-1si and controls (p < 0.05). (B) and (C) Western blot analysis of cyclin D1 and p21 in MCF-7 cells 48 h after transfection. Relative levels of protein are indicated. β-actin levels are shown as loading control. Compared with blank control and GFPsi, a reduction in the expression of cyclin D1 and an increase in the expression of p21 were also noticed (p < 0.05).