Mammary

The mammary gland is a dynamic organ that undergoes extensive morphological changes through development, puberty, pregnancy, lactation and involution. See MoreDuring pregnancy, the steroid hormones estrogen, progesterone and prolactin regulate the development of alveolar sacs (lobules) lined with luminal cells that produce and secrete milk. Elongated myoepithelial cells form a layer between the luminal cells and the basement membrane, thus constituting the basal cell population. After lactation, the gland involutes, losing much of the complex lobular structure to resemble its virgin state. This process is regulated by mammary stem cells (MaSCs) and lineage-restricted progenitors, which both function to maintain glandular homeostasis while also being poised to undergo extensive expansion and differentiation when required. The hierarchical arrangement and molecular regulation of these MaSCs and progenitors is not fully understood. The ability to prospectively identify, isolate and culture human mammary stem and progenitor cells will improve our understanding of the development of this unique organ and our success in defining therapeutic strategies for targeting cells-of-origin in breast cancer.

Read this mini-review to learn more about mammary stem cells.