Figure 4

E2 stimulation of ICI182780 treated cells induced the expression and colocalization of ERα and Ki-67. A, E2 stimulation of cells released from ICI182780 treatment. MCF-7 cells were treated with ICI182780 for 72–96 hr, then ICI182780 was removed by washing with serum-free medium. After removal of ICI182780, cells were treated by 5 nM E2 for 24 hr; control cells were replaced with medium without E2. Magnification, 200×. B, stimulation of E2 by adding E2 directly to cells under ICI182780 treatment. Cells were treated with 10 nM ICI182780 for 72–96 hr, then 100 nM E2 was added directly to the cells without removing ICI182780 for estrogen stimulation. The expression of ERα and Ki-67 was evaluated by immunofluorescent staining. Overlay of the ERα-staining and Ki-67 staining showed the colocalization (Merge). DAPI was used for nuclear staining. Magnification, 200×.