Breast Cancer Research and Treatment

, Volume 67, Issue 2, pp 93–109

Characterization of bipotent mammary epithelial progenitor cells in normal adult human breast tissue


  • John Stingl
    • Department of AnatomyUniversity of British Columbia
  • Connie J. Eaves
    • Department of Medical GeneticsUniversity of British Columbia, Terry Fox Laboratory, British Columbia Cancer Agency
  • Iman Zandieh
    • Department of AnatomyUniversity of British Columbia
  • Joanne T. Emerman
    • Department of AnatomyUniversity of British Columbia

DOI: 10.1023/A:1010615124301

Cite this article as:
Stingl, J., Eaves, C.J., Zandieh, I. et al. Breast Cancer Res Treat (2001) 67: 93. doi:10.1023/A:1010615124301


The purpose of the present study was to characterize primitive epithelial progenitor populations present in adult normal human mammary tissue using a combination of flow cytometry and in vitro colony assay procedures. Three types of human breast epithelial cell (HBEC) progenitors were identified: luminal-restricted, myoepithelial-restricted and bipotent progenitors. The first type expressed epithelial cell adhesion molecule (EpCAM), α6 integrin and MUC1 and generated colonies composed exclusively of cells positive for the luminal-associated markers keratin 8/18, keratin 19, EpCAM and MUC1. Bipotent progenitors produced colonies containing a central core of cells expressing luminal markers surrounded by keratin 14+ myoepithelial-like cells. Single cell cultures confirmed the bipotentiality of these progenitors. Their high expression of α6 integrin and low expression of MUC1 suggests a basal position of these cells in the mammary epithelium in vivo. Serial passage in vitro of an enriched population of bipotent progenitors demonstrated that only myoepithelial-restricted progenitors could be readily generated under the culture conditions used. These results support a hierarchical branching model of HBEC progenitor differentiation from a primitive uncommitted cell to luminal- and myoepithelial-restricted progenitors.

cell cultureflow cytometryhuman mammary epithelial cellstem cells

Copyright information

© Kluwer Academic Publishers 2001