Figure 5

Time course of E2 induced expression of ERα and Ki-67 and cell cycle progression. MCF-7 cells were treated with ICI182780 for 72–96 hr and ICI182780 treatment was stopped by washing with serum-free medium. After removal of ICI182780, cells were treated with 5 nM E2 for various lengths of time (from 2 hr to 44 hr). Cells grown on coverslips were immunofluorescent stained for ERα and Ki-67. Nuclei were stained with DAPI. Cells grown on regular culture dishes were collected for PI staining and analyzed by flow cytometry for cell cycle progression. Magnification, 200×.