Bufadienolides from Venenum Bufonis Inhibit mTOR-Mediated Cyclin D1 and Retinoblastoma Protein Leading to Arrest of Cell Cycle in Cancer Cells

Figure 6

Bufadienolides inhibition of cyclin D1 is mediated by mTOR. Serum-free cultured MCF-7 (a) and DU145 (b) cells were pretreated with bufadienolides (0-10 μg/ml) for 2 h, then stimulated with IGF-1 (10 ng/ml) for 1 h, and finally subjected to western blotting analysis. (c) MCF-7 cells were pretreated with or without SC79 (2μg/ml) for 1h and then treated with bufadienolides (10 μg/ml) for 2 h, followed by IGF-1 (10 ng/ml) stimulation for 1 h, and finally subjected to western blotting analysis. (d) MCF-7 cells were pretreated with or without SC79 (2μg/ml) for 1h and then treated with bufadienolides (10 μg/ml) for 24 h, followed by cell counting analysis. a indicates p<0.01.

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