(a) Levels of caspase activity and ATP content in NCI-H460, NCI-H23, EKVX and NCI-H322M cells treated with increasing doses of either ReoT3D or paclitaxel alone, or both in combination for 24 hours, using the constant ratio combination design . This design format was employed to evaluate the synergistic activity of ReoT3D-chemotherapeutic combination regimens (see text). Shown are the mean ± SD in relative fluorescence units (RFU) and relative luminescence units (RLU) for caspase activity (closed triangle) and ATP content (open circle), respectively, for ReoT3D alone (green), ReoT3D-paclitaxel combination (red) and paclitaxel alone (blue). The data shown are representative of 3 separate experiments. (b) Dose-response curves of caspase activation induced by treatment with ReoT3D alone or ReoT3D-paclitaxel combination for 24 hours fitted by non-linear regression using GraphPad Prism (GraphPad Software, Inc.). Shown as an example are non-linear regression analyses for NCI-H460 and EKVX. See text for statistical analysis on the best-fit values.