Figure 5.

Post-hypoxic cells develop a breast cancer stem cell-like phenotype. (a) Tumor-derived MDA-MB-231 cells were immediately transferred to mammosphere formation media for a 7-day period and imaged by fluorescent microscopy. (b,c) The number and size of mammospheres that formed were assessed by fluorescent image analysis and normalized by the initial number of DsRed+ and GFP+ cells (N = 3, n = 6); p-value is displayed to compare GFP versus DsRed (two-tailed paired t-test). (d) A GSEA of gene set associated with stemness (Zhang et al., 2008) in DsRed+ (LR) and GFP+ (LG) cancer cells purified from lungs. Normalized enrichment score (NES) and p-value (p-val) are displayed. (e) Heatmap of the expression of the top 10 genes driving the enrichment of stemness in (d) in DsRed+ (LR1 and LR2) and GFP+ (LG1 and LG2) lung-derived cancer cells. (f–i) ROC analysis of the top 10 stemness-associated genes for patients that did or did not have a response to treatment with (f) taxane alone; (g) endocrine therapy; (h) anthracycline alone; or (i) fluorouracil, Adriamycin (doxorubicin), and Cytoxan (FAC) therapies.