Fig. 1.

Cleavage of Notch1 in mammary cancer stem-like cells is dependent on CCR7. a-b Primary PyMT-Ccr7 ^WT and Ccr7 ^−/− mammary tumor cells were analyzed by multi-color flow cytometry for Notch1 expression within the stem cell-enriched population CD24⁺CD29^hi. Top = representative flow cytometry plots, bottom = quantification. a Notch1 extracellular domain (ECD) cell surface expression in the PyMT-Ccr7 ^WT and Ccr7 ^−/− mammary stem cell-like population. b Notch1 intracellular domain (ICD) levels in the PyMT-Ccr7 ^WT and Ccr7 ^−/− mammary stem cell-like population. Bulk tumor cells were first labelled for extracellular CD24 and CD29 before permeabilization and staining for Notch1 ICD. a-b n = 4 mice/genotype. FMO = fluorescence minus one, MFI = mean fluorescence intensity. c Notch1 ICD levels in PyMT-Ccr7 ^WT secondary mammospheres, stimulated with CCL19 for varying lengths of time as indicated before lysis for Western analysis. n = 6 mice/experiment