C-terminal of Bfl-1 fused with GFP (BC) inhibits proliferation and induces lung cancer cell apoptosis. A and B , A549 and H157 cells were infected with 10 MOI of the C-terminal of Bfl-1-GFP (BC) or control-GFP (Con) adenovirus and Tet-off adenovirus, and maintained with or without doxycycline for 72 h. In these environments, the expression of BC or GFP was inhibited in the presence of doxycycline and induced in its absence. Cell viabilities were determined using CCK-8 assays, and are expressed the mean percentages of control adenovirus infected cells as determined by three independent experiments. Error bars represent SDs (A). Cellular morphologies were examined by fluorescence microscopy (B). C, D and E , A549 cells were transfected with BC or Con and Tet-off adenoviruses, and cultured in the absence of doxycycline for 72 h. Active caspase-3 levels were measured by flow cytometry using PE-conjugated anti-active caspase-3 antibody (C). After infecting cells for 48 h, they were lysed and 100 μg of whole cell lysates were treated with caspase activity assay buffer containing the peptide caspase substrate DEVD-pNA, for 4 h. Results are the average absorbance at 405 nm of experiments conducted in triplicate, and error bars represent SDs (D). After infecting cells for 72 h, total genomic DNA was extracted and subjected to electrophoresis in 2% agarose gel to examine DNA fragmentation patterns (E).