Sca-1(pos) cells in the mouse mammary gland represent an enriched progenitor cell population.
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.
Welm
Bryan E
BE
Program in Cell and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77035, USA.
Tepera
Stacey B
SB
Venezia
Teresa
T
Graubert
Timothy A
TA
Rosen
Jeffrey M
JM
Goodell
Margaret A
MA
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
D000950:Antigens, Ly; C074650:Ly6a protein, mouse; D008565:Membrane Proteins