Flow cytometric analysis of DNA content and caspase-3 activation in NSCLC cells treated with either ReoT3D (MOI = 20) or paclitaxel alone (0.1 or 1 μM), or both in combination. (a) Shown are scattergrams (top) and histograms (bottom), ungated, of NCI-H23 cells treated with the indicated agent(s) for 24 hours. Harvested cells were fixed, permeabilized and stained with FITC-conjugated anti-active caspase-3 antibody followed by PI staining. Each histogram depicts the DNA content of cells in G1 (2N) and G2/M (4N), while the scattergrams demonstrate the proportion of cells with activated caspase-3 in different cell cycle phases. Values shown in each quadrant of scattergrams represent the percentages of cells. Of note, the histograms also show the apoptotic subdiploid peak (sub-2N), especially enhanced in paclitaxel-treated NCI-H23 cells. (b) The effects of ReoT3D-paclitaxel combination on caspase-3 activation and DNA content were compared among NCI-H23, NCI-H460, EKVX and NCI-322M. These NSCLC cells were analyzed as described in (a). Shown are the percentages of cells positive or negative for activated caspase-3 in sub- G1/G1 or post-G1 phases. The data shown in (a) and (b) are representative of 2 experiments.