DTX or paclitaxel resistance is correlated with decreased apoptosis and changes in cell-cycle distribution on exposure to drugs. (A) Flow cytometric analysis of apoptosis in parental SPC-A1 and DTX-resistant SPC-A1/DTX cell in the presence of the indicated concentrations of DTX (0, 0.5, 5.0 µg/L) or paclitaxel (0, 0.2, 2.0 µg/L). (B) Flow cytometric analysis of cell cycle in parental SPC-A1 and DTX-resistant SPC-A1/DTX cell without or with DTX treatment (1.0 µg/L). Results represent the average of three independent experiments (mean ± SD). *p < 0.05 and **p < 0.01 compared with parental SPC-A1.