High density cultures of HCT116 (A) or HCT116R (B) 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 1, 3, 7, and 10 days, and pictures of the native cultures taken. Pictures are representative of three individual experiments. Colonosphere size was measured and results presented are mean values with standard deviations from three independent experiments. C: High density cultures of HCT116, HCT116+ch3 and their respective 5-FU-chemoresistant 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 10 days, colonosphere size was measured and results presented are mean values with standard deviations from three independent experiments. Significant values are marked with (*).