fig3

Figure 3. Obatoclax treatment enhances TRAIL-induced caspase cleavage and increases TRAIL receptor expression in a cell-dependent way. (A) Caspase- and PARP cleavage were determined by Western blot analysis after exposure to obatoclax (2 µM for A549 and 0.5 µM for SW1573), TRAIL (both cell lines 50 ng/mL), or the combination using pre-incubation or concurrent protocols for A549 and SW1573 cells, respectively. (B) Cell surface expression of TRAIL-R1 and TRAIL-R2 were determined by FACS analysis after 48-h exposure to 0.5 or 2 μM for A549 and SW1573 cells, respectively. Western blots show a representative result from at least three separate experiments. Values are means ± SEM of at least three separate experiments. Statistics: *P < 0.01, 48 h > 0 h; ^#P < 0.05, 48 h < 0 h.