15d-PGJ2 enhance TRAIL sensitivity in various leukemia cell lines. (A) Annexin-V/PI staining; 3.5–5.0 × 105 cells/mL were incubated for 48 hours with 15d-PGJ2, TRAIL, or both. Percentages of Annexin-V-positive cells are indicated. Concentrations of each agent are as follows. KK1, ST1, and SO4: 10 μM 15d-PGJ2 and 500 ng/mL TRAIL. HL60, HS-sultan, Ramos, and K562: 10 μM 15d-PGJ2 and 125 ng/mL TRAIL. THP-1: 10 μM 15d-PGJ2 and 10 ng/mL TRAIL. MOLT-4: 2.5 μM 15d-PGJ2 and 125 ng/mL TRAIL. (B) 5.0 × 105 cells/mL cells were incubated for 48 hours with 500 ng/mL TRAIL, 10 μM 15d-PGJ2, both, or neither. Cell proliferation was assessed by MTS assay. (C) Effect of 15d-PGJ2 treatment on PPARγ expression. Cells were treated for 24 hours using the above described concentrations of 15d-PGJ2, and Western blot analysis was performed using 30 μg of the cell extract. (D) Proposed cascade of FCB-mediated sensitization to TRAIL-induced apoptosis. Values are expressed as mean plus or minus SD.
