a NB4 cells were treated for 24 h with either 1 µM ATRA, 50 ng/ml TNF-α, or 1000 U IFN-α. Cells were subjected to immunoblot and probed with antibodies as indicated. Different membranes with the same samples were used; n = 3. b NB4 cells were stimulated for the indicated times with 1 µM ATRA, 5 µM MS-275, 100 nM LBH589 (LBH), or 10 nM FK228 (FK), lysed, and subjected to immunoblot. Different membranes with the same samples were used; n = 3. c FDCP-1 cells stably expressing rtTA3 or rtTA3 and C/EBPα p42 were treated with 1 µg/ml doxycycline for 48 h, and expression levels were detected by Immunoblot analysis with the indicated antibodies. d Protein expression was induced as in c, and FDCP-1 cells were simultaneously treated with the indicated concentrations of MS-275. After 48 h, the cells were harvested and living cells were determined by flow cytometry; n = 3