BioProject

To get molecular insight into age- and compartment-specific changes in telomere maintenance and associated properties in human mammary gland, we analyzed distinct subsets of normal human mammary epithelial cells. More...

To get molecular insight into age- and compartment-specific changes in telomere maintenance and associated properties in human mammary gland, we analyzed distinct subsets of normal human mammary epithelial cells. The cells were isolated by fluorescent activated cell sorting (FACS) directly from mammary tissue obtained from normal women undergoing reduction mammoplasties with concomitant removal of hematopoietic and endothelial cells by depletion of CD45pos and CD31pos cells. The three epithelial cell populations then isolated were: (i) CD49fhiEPCAMneg/low cells, (ii) CD49fposEPCAMpos cells and (iii) CD49fnegEPCAMpos cells. The CD49fhiEPCAM-/low cells are selectively enriched in mammary stem cells with functional mammary gland regenerating activity in suitably transplanted immunodeficient mice, bipotent progenitors that form colonies of adherent myoepithelial and luminal cells in vitro, myoepithelial-restricted progenitors that form colonies of exclusively adherent myoepithelial cells in vitro, and mature myoepithelial cells that are not clonogenic (collectively referred to as basal cells, BCs). The CD49fposEPCAMpos cells are selectively enriched in luminal progenitors (referred to as luminal progenitors, LPs); and the CD49fnegEPCAMpos cells are selectively enriched in mature luminal cells (referred to as luminal cells, LCs). Differences in gene expression in general and telomere associated genes in particular were elucidated by analyzing mammary epithelial subpopulations. Overall design: Total RNA was isolated from 24 samples obtained from FACS purification of mammary epithelial subpopulations from 9 reduction mammoplasty breast tissues. Global gene expression profiling was performed by array. Less...