title: Sca-1(pos) cells in the mouse mammary gland represent an enriched progenitor cell population.
abstract: Mammary epithelium can functionally regenerate upon transplantation. This renewal capacity has been classically ascribed to the function of a multipotent mammary gland stem cell population, which has been hypothesized to be a primary target in the etiology of breast cancer. Several complementary approaches were employed in this study to identify and enrich mammary epithelial cells that retain stem cell characteristics. Using long-term BrdU labeling, a population of label retaining cells (LRCs) that lack expression of differentiation markers has been identified. LRCs isolated from mammary primary cultures were enriched for stem cell antigen-1 (Sca-1) and Hoechst dye-effluxing "side population" properties. Sca-1(pos) cells in the mammary gland were localized to the luminal epithelia by using Sca-1(+/GFP) mice, were progesterone receptor-negative, and did not bind peanut lectin. Finally, the Sca-1(pos) population is enriched for functional stem/progenitor cells, as demonstrated by its increased regenerative potential compared with Sca-1(neg) cells when transplanted into the cleared mammary fat pads of host mice.
authors.affiliation: Program in Cell and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77035, USA.
authors.forename: Bryan E
authors.initials: BE
authors.lastname: Welm
authors.forename: Stacey B
authors.initials: SB
authors.lastname: Tepera
authors.forename: Teresa
authors.initials: T
authors.lastname: Venezia
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Graubert
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Rosen
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Goodell
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D008321:Mammary Glands, Animal / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D013234:Stem Cells / Q000166:cytology* / Q000276:immunology / Q000378:metabolism
chemical_list: D000950:Antigens, Ly; C074650:Ly6a protein, mouse; D008565:Membrane Proteins