Figure 1.

E2-induced DNA synthesis requires PI3K in HepG2 cells. [³H]thymidine incorporation into DNA has been evaluated as described in MATERIALS AND METHODS in HepG2 cells treated with the PI3K inhibitors Ly 294002 (Ly) and wortmannin (W) (10 μM each) or with the pure antiestrogen ICI 182,780 (ICI) (1 μM) and then stimulated for 1 h with vehicle (C) or 17β-estradiol (E2) (10 nM). Data are expressed as disintegrations per minute (dpm) per total protein extracted ± SD of four independent experiments. ^*p < 0.001 compared with respective control values (C), determined using Student's t test. °p < 0.001 compared with respective E2 values (E2), determined using Student's t test.