Figure 1.

Synergistic effects of rapamycin and CN-A on the growth of MCF-7 cells. (a) Cells (3 × 10⁴ cells/ml) were cultured with various concentrations of rapamycin and CN-A for 5 days. After culture, cells were stained with May–Grunwald–Giemsa. (b) Cells (3 × 10⁴ cells/ml) were cultured without (white circle) or with (white triangle) 0.5 ng/ml rapamycin, 10 μg/ml CN-A (white square), or 0.5 ng/ml rapamycin plus 10 μg/ml CN-A (black circle) for the indicated number of days. The values are expressed as mean ± standard deviation of four determinations. (c) Cells were cultured without (white circle) or with (white triangle) 0.5 ng/ml rapamycin, 10 μg/ml CN-A (white square), or 0.5 ng/ml rapamycin plus 10 μg/ml CN-A (black circle) for the indicated number of days. The culture medium was replaced by fresh medium at least once every 5 days. The cell density was kept at 1–8 × 10⁴ cells/ml. The values are expressed as mean ± SD of four separate experiments. CN-A, cotylenin A.