Sca-1(pos) cells in the mouse mammary gland represent an enriched progenitor cell population

Dev Biol. 2002 May 1;245(1):42-56. doi: 10.1006/dbio.2002.0625.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Ly / metabolism*
  • Cell Differentiation
  • Cell Division
  • Epithelial Cells / cytology
  • Epithelial Cells / immunology
  • Epithelial Cells / metabolism
  • Female
  • Fluorescent Antibody Technique
  • Mammary Glands, Animal / cytology
  • Mammary Glands, Animal / immunology
  • Mammary Glands, Animal / metabolism*
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Stem Cells / cytology*
  • Stem Cells / immunology
  • Stem Cells / metabolism


  • Antigens, Ly
  • Ly6a protein, mouse
  • Membrane Proteins