Basal, luminal and myoepithelial cells: immunophenotypical and molecular characterization

Although experimental data clearly confirm the existence of self-renewing mammary stem cells, the characteristics of such progenitor cells have never been satisfactorily defined. Using a double immunofluorescence technique for simultaneous detection of the basal cytokeratin 5, the glandular cytokeratins 8/18 and the myoepithelial differentiation marker smooth muscle actin (SMA), the presence of CK5+ cells in human adult breast epithelium could be demonstrated [1]. As proposed more than a decade ago [2], these cells have the potential to differentiate to either glandular (CK8/18+) or myoepithelial cells (SMA+) th…