Fig. 4.
The cancer stem cell (CSC)-like population is further enriched in secondary xenografts derived from the enhanced green fluorescent protein (EGFP)+ MDA-MB-231 cells. a Generation of the secondary xenografts. b, c Surface levels of CD24 and CD44 are analyzed by fluorescence-activated cell sorting. b Average CD24+ populations from six individual tumors (***p < 0.001, Student’s t test). c Average CD44++ (right-pointing arrow) populations from three individual tumors (*p < 0.05, Student’s t test). d Quantitative RT-PCR analysis of expression of CD24 and CD44 genes in the EGFP+ and EGFP− cells freshly isolated from either the 2nd or 1st xenografts (n = 3; *p < 0.05, **p < 0.01, Student’s t test). e Clonogenic growth of sorted EGFP+ and EGFP− cells freshly isolated from the 2nd xenografts in comparison to the unsorted tumor cells from the 1st xenografts (n = 3; *p < 0.05, ***p < 0.0001, Student’s t test)