Fig. 6.

P4-induced CK5⁺ cells are more invasive and sphere-initiating than CK5⁻ cells. T47D^K5pGFP cells were treated with vehicle (EtOH) or 100 nM P4 for 24 h and the GFP^−/+ (CK5^−/+) fractions isolated by FACS as described. a Sorted cell fractions (50,000 each) were placed in invasion chambers for 24 h and the number of invading cells per field measured by Image J analysis (NIH). Graph of mean number of invasive cells per field for each condition. Boxes represent range and lines represent means. All sets were compared by one-way ANOVA/Tukey; *p < 0.05, P4-treated CK5⁺ vs. CK5⁻. b Sorted cells (300 each) were placed in mammosphere/3D-Matrigel culture, and the number of spheres ≥50 μm measured by automated counter after 7 days. Graph of mean number of spheres per field for each condition. Boxes represent range and lines represent means. All data sets were compared by one-way ANOVA/Tukey; **p < 0.01, ***p < 0.001, P4-treated CK5⁺ compared to all other groups