Characterization of Bipotent Mammary Epithelial Progenitor Cells in Normal Adult Human Breast Tissue

Breast Cancer Res Treat. 2001 May;67(2):93-109. doi: 10.1023/a:1010615124301.

Abstract

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), alpha6 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 alpha6 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / biosynthesis
  • Biomarkers / analysis
  • Breast / cytology*
  • Cell Adhesion Molecules / biosynthesis
  • Cell Culture Techniques
  • Cell Differentiation*
  • Epithelial Cell Adhesion Molecule
  • Epithelial Cells / physiology*
  • Female
  • Flow Cytometry
  • Gene Expression Regulation
  • Humans
  • Integrins / biosynthesis
  • Mucin-1 / biosynthesis
  • Stem Cells / physiology*

Substances

  • Antigens, Neoplasm
  • Biomarkers
  • Cell Adhesion Molecules
  • Epithelial Cell Adhesion Molecule
  • Integrins
  • Mucin-1