Effect of PI3K/Akt and MAPK pathways on Cox-2 expression in MCF-7/DOX cells. (A) Western blot analysis in MCF-7/DOX cells treated with EGF (100 ng/mL) for 8 h. (B) Western blot analysis of MCF-7/DOX cells that were treated with LY294002 (10 μM) or U0126 for 9 h. EGF (100 ng/mL) was added 8 h before cell harvest. (C, D) Invasion assay of MCF-7/DOX cells treated with either (C) 10 μM LY294002 or (D) U0126 for 18 h. Cell proliferation was also measured with using the MTT assay 24 h after treatment. *P < 0.01 (t-test). (E) Western blot and RT-PCR analysis of MCF-7/DOX cells that were transfected with control or Cox-2 siRNA. (F) Semiquantitative RT-PCR analysis of uPA, MMP-2, and MMP-9 in MCF-7/DOX cells transfected with siRNAs specific for Cox-2 and treated with LY294002 (10 μM) or U0126 (10 μM) for 48 h.