Figure 5.

Proteotoxic stress is required for cell death induced by the combination of NFV and BZ. H157 cells were pre-treated or not with 1 μg/ml (3.6 μM) CHX for 3 h, followed by treatment with either DMSO, 10 μM NFV, 12.5 nM BZ, the combination, or 6 μM Tunicamycin as a control for 48 h. RPMI8226 cells were pre-treated or not with 0.1 μg/ml (0.36 μM) CHX for 3 h, followed by treatment with either DMSO, 10 μM NFV, 6.25 nM BZ, the combination, or 6 μM Tunicamycin as a control for 24 h. (a) Inhibition of protein synthesis decreases vacuolization of cytoplasm in H157 cells. Optical microscope images were taken at × 300 magnifications. Arrows, point to vacuolization. (b) Decrease of proteotoxic stress. The indicated markers were assessed by immunoblotting. (c) Decrease of total cell death by cycloheximide. Cell death assay with propidium iodide were performed. Columns, mean from at least three separate experiments; bars, S.D. *P<0.001