Identification of quiescent and spatially restricted mammary stem cells that are hormone responsive Academic Article uri icon

abstract

  • Despite accumulating evidence for a mammary differentiation hierarchy, the basal compartment comprising stem cells remains poorly characterized. Through gene expression profiling of Lgr5+ basal epithelial cells, we identify a new marker, Tetraspanin8 (Tspan8). Fractionation based on Tspan8 and Lgr5 expression uncovered three distinct mammary stem cell (MaSC) subsets in the adult mammary gland. These exist in a largely quiescent state but differ in their reconstituting ability, spatial localization, and their molecular and epigenetic signatures. Interestingly, the deeply quiescent MaSC subset (Lgr5+Tspan8hi) resides within the proximal region throughout life, and has a transcriptome strikingly similar to that of claudin-low tumours. Lgr5+Tspan8hi cells appear to originate from the embryonic mammary primordia before switching to a quiescent state postnatally but can be activated by ovarian hormones. Our findings reveal an unexpected degree of complexity within the adult MaSC compartment and identify a dormant subset poised for activation in response to physiological stimuli.

authors

  • Fu, Nai Yang
  • Rios, Anne C
  • Pal, Bhupinder
  • Law, Charity W
  • Jamieson, Paul
  • Liu, Ruijie
  • Vaillant, François
  • Jackling, Felicity
  • Liu, Kevin He
  • Smyth, Gordon K
  • Lindeman, Geoffrey J
  • Ritchie, Matthew E
  • Visvader, Jane E

publication date

  • 2017