The p53 pathway is functional in MECP2-expressing cells. (a) LNCaP/WB3 and LNCaP/MECP2 cells were treated with cycloheximide during the indicated time. Analysis of p53 protein steady-state level was performed by immunoblotting. (b) In all, 500 000 LNCaP/WB3 and LNCaP/MECP2 cells were seeded into 10-cm dishes. Etoposide (20 μ M) or Camptothecin (20 μ M) was added the next day and treatment was continued for 10 h. Cell extracts were then prepared and MECP2, p53, and p21 or actin proteins were detected by immunoblotting. (c) In all, 400 000 LNCaP/WB3 or LNCaP/MECP2 cells were seeded into 10-cm dishes and treated once with 4 μ M etoposide. Plates were stained with Crystal Violet after 7 days. (d) In all, 400 000 control or MECP2-expressing cells were seeded into 10-cm dishes and treated with 2 μ M camptothecin. Plates were stained with Crystal Violet after 9 days.