Figure 1

Identification and confirmation of isolated HeLa cancer stem cells (hCSCs). A) Representative FACS histograms showing increased CD44 and decreased CD24 expression in hCSCs compared with HeLa cells B) Summary of FACS analyses showing the percentage of hCSCs expressing CD44 and CD24 (n = 3) C) The Hoechst exclusion assay showing transmitted, Hoechst-stained, and overlaid images of HeLa cells and hCSCs. Hoechst 33342 dye emits blue fluorescence when bound to dsDNA. Yellow arrows show Hoechst-excluded cells lacking dark-blue nuclei (200-μm scale), which were typically higher in hCSCs than in HeLa cells. D) Quantification of Hoechst-dye-excluded cells showing a higher exclusion rate in hCSCs (n = 3). E) In vivo tumorigenicity was compared in NOD/SCID mice (four animals per group) 3 weeks after xenotransplantation of HeLa cells, hCSCs, or vehicle (naïve control), showing higher tumor counts in the hCSC group. All data are expressed as means ± SEM except for in vivo tumor counts. Asterisks indicate statistically significant differences between the groups indicated, ***p ≤ 0.001.