Mutated RAS induces cox-2 expression and activation in MM cells. (A) Western analysis for cox-2 expression in wild-type (WT), N-RAS, and K-RAS MM cells after 48 and 72 hours of IL-6 depletion. Purified cox-2 electrophoresis standard served as positive cox-2 control. (B) cox-1 expression in WT, N-RAS, and K-RAS cells after 48 hours of IL-6 depletion. (C) Western analysis of cox-2 expression in WT, N-RAS, and K-RAS cells cultured for 0 or 48 hours with or without IL-6 (1000 U/mL). (D) Conditioned media were analyzed for PGE2 level. The concentration of PGE2 is reported as picogram of PGE2/mL of media/mg of total protein lysate, mean ± SD.