FIGURE 6.

Bafilomycin reverses the BI-1-regulated ER stress response. A, Neo and BI-1 cells were treated with 1 or 10 nm bafilomycin (Bafi) for the indicated times, and Western blotting was performed with anti-GRP78, CHOP, or β-actin antibody. B, Neo and BI-1 cells were subjected to 5 μm thapsigargin (Tg) or 5 μg/ml tunicamycin (Tu) with or without 10 nm bafilomycin for 0, 2, 4, 8, and 12 h, and Western blotting was performed with anti-GRP78, CHOP, or β-actin antibody. Representative blots for thapsigargin and tunicamycin are shown in the left and right panels, respectively. Neo and BI-1 cells were subjected to 5 μm thapsigargin (left) or 5 μg/ml tunicamycin (right) with or without the indicated concentrations of bafilomycin for 12 h. C and D, cell viability (C) and caspase-3 activity (D) were analyzed. Data represent the mean ± S.E. (n = 4). *, p < 0.05; significantly different from thapsigargin-treated BI-1 cells, #, p < 0.05; significantly different from tunicamycin-treated BI-1 cells. In panels C and D, each value is expressed as the mean ± S.E. of three independent experiments. Con, control.