Fig. 4.

Formation of primary and secondary colonospheres by the chemo-resistant HCT-116 cells is inhibited by CDF. (A) Effect of 5-FU + Ox alone or in combination with increasing concentrations of either CDF or curcumin on the formation primary colonospheres by chemo-resistant HCT-116 cells (upper panel). The primary colonospheres obtained from respective treatments were then dissociated into single cell suspension, subsequently subjected to secondary sphere formation in the absence of any treatment. To assess post-treatment self-renewing abilities of the colonosphere-derived cells, an equal number of these cells, diluted in stem cell media, were plated in 96-well low attachment plates for secondary colonosphere generation in the absence of any agent (lower panel). (B) Representative photomicrographs showing the extent of colonosphere disintegration in chemo-resistant HCT-116 cells in the absence (control-untreated) or presence of 5-FU + Ox alone or in combination with low dose of either curcumin or CDF. *p<0.001, compared to the corresponding treatment controls.