Fig. 1.
Bcl-2, but not Bcl-XL, prevents apoptosis before and after DMSO-induced erythroid differentiation in MEL cells.
(A) Expression of Bcl-2 and Bcl-XL in MEL cells and derived clones. Cells were grown in the absence or in the presence of DMSO for 5 days. Total protein was isolated from 745A/Neo cells (745A clone stably transfected with neo gene), 745A/Bcl-2 cells (745A clone stably transfected with Bcl-2 sense transcripts), 745A/Bcl-XLS cells (745A clone stably transfected with Bcl-XL sense transcripts), and 745A/Bcl-XLAS cells (745A clone stably transfected with Bcl-XL antisense transcripts), and analyzed by Western blotting with anti–Bcl-2 and anti–Bcl-XL antibodies. Evaluation of β-actin expression was used to control for equal loading. (B) Cell viability of MEL cells. Cells were initiated at 105 cells/mL and cultured with or without 2% DMSO. At the indicated times (days), cell viability was measured by trypan blue dye exclusion. Data represent the mean of triplicate cultures ± standard deviation. (C) DNA fragmentation analyzed by gel electrophoresis followed by staining with ethidium bromide in MEL cells cultured without DMSO (day 5) or with DMSO (day 7). Lane 1: 745A/Neo cells; lane 2: 745A/Bcl-XLS cells; lane 3: 745A/Bcl-2 cells.