Figure 1.

EM011 inhibits cellular proliferation and impedes cell-cycle by causing mitotic arrest followed by apoptosis in PC-3, LNCaP, C4-2, and C4-2B cells. A. Plot of the percentage of cell survival versus EM011 concentrations used for the determination of IC₅₀ values. Cells were treated with increasing gradient concentrations of EM011 for 72 hr, and the percentage of cell proliferation at the indicated drug concentrations, compared with vehicle-treated cells, was measured by the standard sulforhodamine B assay as described in Materials and Methods. The IC₅₀ values of EM011 for all four prostate cancer cell types are indicated on the panel. B. The effect of EM011 on the cell-cycle profile of all four prostate cancer cells are shown in a three-dimensional disposition. Cells were harvested for analysis at the indicated times, stained with PI and analyzed by fluorescence-activated cell sorting (FACS) using Cell-Quest Software. The x axis shows the intensity of PI fluorescence, which is indicative of the total DNA content of cells in different cell-cycle phases. The y axis depicts the number of cells in each phase of the cell-cycle and the z axis indicates the time points (0, 24, 48, and 72 hr). Results are representative of three experiments done in triplicate. C. Quantitative representation of mitotic and apoptotic index as a function of time of treatment with 25 μM EM011.