Figure 3

DsRed⁺ (Sox2⁺) colon cancer cells had cancer stem cell-like properties. (A) Schematic representation of the plasmid of Sox2 promoter activity-dependent cell visualization system with DsRed fluorescence. (B) HCT116 (left) or HT29 (right) cells were infected with empty-vector (top, Mock) or the vector encoding Sox2 promoter followed by DsRed gene (bottom, Infection). The percentage of DsRed⁺ cells was measured by flow cytometry. DsRed⁺ cells were visualized by microscopy as red signal. (C) Time-lapse image of DsRed⁺ cells showing asymmetric division of DsRed⁺ cells. Arrows indicate DsRed⁺ cells. (D) The expression of undifferentiated markers Sox2, Oct-4, and Nanog, and cancer stem cell markers Bmi-1, CD44v9, and Klf-5 was examined between DsRed⁺ and DsRed⁻ HCT116 (top) or HT29 (bottom) cells. Values are expressed as the fold value of DsRed⁻. Sox2-expressing DsRed⁺ cells often exhibited high expression of undifferentiated markers or cancer stem cell markers. GAPDH was used as the loading control. *P < 0.05.