Proliferative Activity of Colorectal Cancer Cells with Different Levels of CD133 Expression

We studied proliferative activity of colorectal cancer cells with different expression level of CD133 molecule associated with cancer stem cells phenotype. Analysis of BrdU incorporation into Caco-2 and HT-29 cell lines showed that the percentage of cells in the DNA synthesis phase in the CD133^+/high population is higher than in CD133^-/low population. The expression of proliferation marker Ki-67 and the percentage of Ki-67⁺ cells were also higher in the CD133^+/high population. Colorimetric analysis with crystal violet dye showed that the number of cells after 10-days culturing was higher in the CD133^+/high population in both cell lines. These findings suggest that cells with high level of CD133 expression are characterized by higher proliferative activity, which can contribute to the tumor progression.