Figure 3. Cbl is required for berberine inhibition of proliferation by berberine in IMCE cells.

Cells were transfected with Cbl siRNA or non-targeting siRNA. (A) at the 30-hour of posttransfection, cells were treated with berberine at 50 µM for 18 hours under non-permissive condition in the presence or absence of EGF (30 ng/ml) treatment for 5 minutes. Cellular lysates were collected for Western blot analysis to detect Cbl expression and indicated signaling pathways. (B) at the 24-hour of posttransfection, cells were treated with berberine at 50 µM for 24 hours under non-permissive condition in the presence or absence of EGF (30 ng/ml) treatment for 24 hours to detect cell proliferation, as described in Figure 2A. Density plots with BrdU-FITC vs PI and percentages of cell s in G1, S, and G2 phase are shown. Data in this Figure are representative of three separate experiments.