Fig. 6

GTCpFE pre-treatment reduces the CD44⁺CD24⁻ population, MS growth, and tumor initiation capacity. a The CD44⁺CD24⁻ population was determined by FACS analysis of MDA-MB-231 cells treated with 50 μM GTCpFE for 72 hours. Quantitation of each population percentage (left) and representative scatter plots from FACS (right) are shown. *** P < 0.001. b MS formation was measured following pretreatment of MDA-MB-231 cells with 50 or 100 μM GTCpFE for 72 hours. GTCpFE is then withdrawn prior to seeding in MS culture. MS growth inhibition was plotted as % of DMSO vehicle control (left) and representative pictures of MS growth are shown (10×, right). *** P < 0.001; ND, none detected. c The number of xenograft tumors initiated over time (left panel) and their growth rates (right panel) was determined from GTCpFE or vehicle pre-treated MDA-MB-231 cells. * P < 0.05, ** P < 0.01