Fig. 2: Proliferative response of cancer cells to indicated compounds.

a–c the effect of concentrations of different compounds on the growth of the cells. Cells were cultured in 10% PRF-CT with E₂ 1 nM (MCF-7 and ZR-75-1) or without E₂ (MDA-MB-231) for 3 days before plating. Cells were seeded in 96-well plates and 24 h later they were exposed to different concentrations (1 nM– 10 μM) of compounds for 6 days (MCF-7 and ZR-75-1) or 3 days (MDA-MB-231). Cell growth was measured as described in the “Materials and methods”. The proliferation of cells is expressed as the ratio of the cells compared with the control wells (untreated cells). d, e Influence of different compounds on the cell cycle of MCF-7 cells. MCF-7 cells were cultured in 10% PRF-CT with E₂ (1 nM) for 3 days before plating. Cells were seeded in six-well plates and, the next day, starved in PRF for 24 h. Cells were exposed to different compounds at a concentration of 100 nM for 72 h, and then subjected to cell-cycle analysis as described in “Materials and methods”. f MCF-7 cells on poly-l-lysine-coated glass coverslips were exposed to compounds (100 nM) in 10% PRF-CT with 1 nM E₂ for 72 h. Control cells were treated with vehicle. DAPI stains DNA, and the secondary anti-mouse antibody to detect the antibody bound to Ki-67 is labeled with the cyanine dye Cy3. The cells were stained with DAPI (blue). Immunofluorescence staining of Ki-67 of cells was observed using fluorescence microscope. Red: Ki-67; blue: nucleus.Typical image is shown. Scale bars: 10 μm. Data represent a mean ± SEM of three independent experiments, each in triplicate; bars, SEM. *P ≤ 0.05 vs. control