Curcumin suppresses PPARδ expression and related genes in HT-29 cells

AIM: To investigate the effects of curcumin on the expression of peroxisome proliferator-activated receptor delta (PPAR delta) and related genes in HT-29 cells. METHODS: HT-29 cells were treated with curcumin (0-80 mu mol/L) for 24 h. The effects of curcumin on the morphology of HT-29 cells were studied by Hoechst 33342 staining. The activity of caspase-3 was determined using DEVD-pNA as substrate. The levels of peroxisome PPAR delta, 14-3-3 epsilon and vascular endothelial growth factor (VEGF) in HT-29 cells were determined by Western blotting analysis and their mRNA expression was determined by real-time quantitative RT-PCR. RESULTS: Treatment with 10-80 pmol/L curcumin induced typical features of apoptosis and activated the caspase-3 in HT-29 cells. The expression of PPAR delta, 14-3-3E and VEGF was reduced and the activity of beta-catenin/Tcf-4 signaling was inhibited by curcumin treatment. CONCLUSION: Curcumin can induce apoptosis of HT-29 cells and down-regulate the expression of PPAR delta, 14-3-3E and VEGF in HT-29.