E-selectin does not induce apoptosis in HT29 cells. A to D, HT29 cells were left untreated (A) or were treated with E-selectin at 10 μg/ml for 4 hours (B) or 24 hours (C), or were treated with phenethyl isothiocyanate at 50 μM for 24 hours (D). Cells were fixed and stained with Hoechst dye and examined for nuclear fragmentation. In E, 24 hours after being plated, HT29 cells were left to grow for 96 hours with or without E-selectin or the apoptosis inducer curcumin (75 μM). At the end of the treatments, the cell survival was evaluated by their ability to convert tetrazolium salt into formozan (WST-1 assay), which was monitored at 450 nm.