A) COX-2 enzyme activity was measured after treatment with DMSO, paclitaxel or paclitaxel/celecoxib (50µM) for 2 hrs. Data represented as mean ± SD; N=3. B) Western blot analysis of Cox-2, Caspase-3 and HuR in 74B and 11A cells treated with DMSO, paclitaxel or paclitaxel/celecoxib for 2 hrs. β-actin: loading control. Representative western blots from three independent experiments are shown. C–D) Measurement of apoptosis in 74B and 11A cells after DMSO, paclitaxel, celecoxib or paclitaxel/celecoxib treatment for 2 hrs. The percentage of early (bottom right quadrant) and late (top right quadrant) apoptotic cells are depicted in the scatter plots and bar graph. Data represented as mean ± SD; N=2. E) UMSCC-11A and 74A cells transiently over expressing GFP-CP1 were treated with DMSO or paclitaxel for 16 hrs. HuR and caspase-3 expression was analyzed by western blot. β-actin: loading control. Representative western blots of three independent experiments are shown.