Effect of gefitinib and rofecoxib on p21, p27 and p-AKT. Ist-Mes-1, Ist-Mes-2 and MPP89 cell lines treated with gefitinib 25 μM , rofecoxib 4 μM and the combination gefitinib 25 μM +rofecoxib 4 μM for 48 hours were used to evaluate the effect of treatment on p21, p27, p-AKT and AKT in western blot. Actin was used as loading control. An increase in the amount of p27 and p21 in Ist-Mes-2 cells but no significant change in Ist-Mes-1 and MPP89 was reported. Phosphorylated AKT (p-AKT) was significantly reduced in Ist-Mes-1 and MPP89 by treatment with rofecoxib. No detectable p-AKT was found in Ist-Mes-2 cells.