Increase of 15d-PGJ2 expression by sFCB treatment. (A) Measurement of PGs. 3.5 × 105 KOB cells/mL were incubated for 24 hours with 2.5 μg/mL of sFCB and/or 50 μM NS398. Activation of PGE2, PGD2, and 15d-PGJ2 was detected by EIA. (B) 15d-PGJ2 enhances sensitivity to TRAIL. Cells were incubated for 48 hours with the indicated concentrations of 15d-PGJ2 and/or 500 ng/mL of TRAIL. Cell proliferation was assessed by MTS assay. (C) Evaluation of apoptosis. KOB cells were incubated for 48 hours with 10 μM 15d-PGJ2 and/or 500 ng/mL of TRAIL and analyzed as described in Figure 1E. (D) Combination use of synthetic PPARγ agonists and TRAIL. 3.5 × 105 KOB cells/mL were incubated for 48 hours with the indicated concentrations of TZDs and/or 500 ng/mL of TRAIL and cell proliferation was assessed by MTS assay. (E) Western blot analysis. 3.5 × 105 KOB cells/mL were incubated for 24 hours with 15d-PGJ2. 30-50 μg of the cell extract was used and were detected with the antibodies described in “Materials and methods, Western blot analysis and antibodies.” (F) Activities of NFκB. Cells were incubated for 24 hours with or without 10 μM 15d-PGJ2. The activities of p50 and p65 were evaluated as described in Figure 3B. Values are expressed as mean plus or minus SD.
