Background: Cancer stem-like cells (CSCs) in colorectal cancers (CRC) may account for the failure of treatments because they are resistant to many current anticancer therapies. Salinomycin, a potassium ionophore, was recently identified as a selective inhibitor of breast CSCs.
Methods: The human CRC cell lines HT29 and SW480 were treated with salinomycin and oxaliplatin. Cell viability was determined with cell counting kit 8. Fraction of CD133+ cell subpopulations was assessed by Flow Cytometric analysis. Clonogenecity and migration were determined with soft agar and Boyden chamber assays. Molecular changes were assessed by immunofluorescence staining, RT-PCR, and Western blot analysis.
Results: We report that salinomycin reduces the proportion of CD133+ subpopulations in human CRC HT29 and SW480 cells. Furthermore, salinomycin treatment decreases colony-forming ability and cell motility in HT29 cells. Moreover, salinomycin downregulates the expression of vimentin and induces the E-cadherin expression in HT29 cells.
Conclusions: This study demonstrates the ability of salinomycin to selectively target "CD133+" cell subpopulations and decrease the malignant traits in colorectal cancer lines.