Figure 2.

Combining NFV with BZ enhances caspase-dependent apoptosis. (a) Enhancement of apoptosis. H157 cells were treated with either DMSO, 10 μM NFV, 12.5 nM BZ, or the combination for the indicated times, and RPMI8226 cells were treated with either DMSO, 10 μM NFV, 6.25 nM BZ, or the combination for the indicated times. Cells were harvested and analyzed by Annexin V binding assays. (b) Induction of caspase and PARP cleavage. H157 and RPMI8226 cells were treated with the drugs at the concentration as described in (a) for 48 and 24 h, respectively. Levels of the indicated markers were assessed by immunoblotting. **Non-specific band. (c) Enhancement of caspase-dependent apoptosis. H157 cells were pre-treated or not with 50 μM Z-VAD for 1 h, followed by treatment with either DMSO, 10 μM NFV, 12.5 nM BZ, or the combination for 48 h. Cells were harvested and analyzed by DNA fragmentation and cell death assays. PARP cleavage was assessed by immunoblotting to confirm inhibition of caspases by Z-VAD. Columns, mean from at least three separate experiments; bars, S.D. *P<0.001