Increase of COX-2 expression by sFCB treatment. (A,C,E) Western blot analysis. 3.5 × 10⁵ KOB cells/mL were incubated for 24 hours with sFCB, NS398, or both at the concentrations and for the time course indicated. Using 30 μg of the cell extract, proteins were detected with the antibodies described in “Materials and methods, Western blot analysis and antibodies.” (B) Effects of TRAIL and NS398. Cells were incubated for 48 hours with NS398 and/or 500 ng/mL of TRAIL and cell proliferation was assessed by MTS assay. (D) Inhibition of synergism. Cells were treated as described in Figure 1E. Indicated concentrations of NS398 were added and cell proliferation was assessed by MTS assay. Values are expressed as mean plus or minus SD.