Fig. 1

MaCSCs have the capacity to differentiate into multiple cell types. (a) A single Py230 cell stained with myoepithelial marker keratin 14 (K14) and luminal marker keratin 8 (K8). (b) Clonal Py230 cells grown on a glass coverslip stained with K14 and K8. Scale bar 20 μm. (c) Clonogenic efficiency of C57Bl/6 MaCSC line Py230 and FVB/N MaCSC line Py9813. (d) Hollow mammospheres of Py230 cells in suspension culture. Scale bar 50 μm. (e,f) Py230 mammosphere stained with K14 and K8. Scale bar 20 μm. (g) Py230 mammosphere grown on collagen exhibits branching structures. Scale bar 100 μm. (h) Confluent Py230 cells spontaneously form domes. (i) Domes become enlarged upon treatment with lactogenic hormones dexamethasone and prolactin. Scale bar 50 μm. (j) Expression of beta-casein by MaCSC lines Py230 and Py9813 following treatment with lactogenic hormones. Data are means ± SEM of triplicate samples. (k) Py230 cells treated with retinoic acid and rosiglitazone express genes associated with adipocyte differentiation. Data are means ± SEM of triplicate samples. Inset: Py230 cells stained with oil red O. Scale bar 10 μm