Effect of selective COX-2 inhibitors on apoptotic death of A549, H460, and H358 cells. A, B: Effect of celecoxib, etoricoxib, rofecoxib, and valdecoxib (30 µM in A549 and H460; 50 µM in H358) on cellular viability following a 48 h incubation period (A) and on DNA fragmentation after 24 h incubation (B). C, D: Concentration-dependent effect of celecoxib on cellular viability of A549, H460, and H358 after a 48 h incubation (C) and DNA fragmentation after a 24 h (A549), 48 h (H460), or 18 h (H358) incubation (D). E: Time-dependent effect of celecoxib (30 µM in A549 and H460; 50 µM in H358) on cellular viability of lung cancer cells. Percent control represents comparison with vehicle-treated cells (100%) in the absence of test substance. Values are means ± SEM of n = 12 (A); n = 3–4 (B, A549, H358, C, H460, H358, D), n = 8 (B, H460), n = 15–20 (C, A549), n = 6 (E). *P < 0.05, **P < 0.01, ***P < 0.001 versus corresponding vehicle control; one-way ANOVA plus Bonferroni (A–D) or Student t-test (E).