Figure 6. Effect of curcumin on 5-FU-induced apoptotic signaling in HCT116, HCT116+ch3 and their respective 5-FU-chemoresistant cell lines in high density cultures.

High density cultures of HCT116 and HCT116+ch3 (left lanel) and of HCT116R and HCT116+ch3R (right panel) cells were either left untreated or were treated with 5-FU (5 µM), curcumin (20 µM), or 5-FU/curcumin in combination (0.1/5 µM). Cultures were evaluated after 3 days and whole cell lysates prepared and analyzed by western blotting for cleavage of PARP. Western blots shown are representative of three independent experiments. The housekeeping protein β-actin served as a positive loading control in all experiments.