Figure 4

Effect of the inhibition of PI3K by LY 294002 on the induction of cyclins D1 and A. MCF-7 cells were starved of serum and E2 during 48 h in the presence or absence of ICI 182780 (10 nM). Last 3 hours of serum deprivation (time −3 h to 0 h), one series of dishes was treated with LY 294002 (LY; 20 μM). Subsequently, at t = 0, all cells were stimulated by the addition of insulin (ins; 1 μM) or E2 (1 μM) for 3 h or 6 h (upper panel) or 19 h (lower panel). After lysis, the different proteins were revealed by after Western blotting using specific antibodies.