The Normal Microenvironment Directs Mammary Gland Development

Abstract

Normal development of the mammary gland is a multidimensional process that is controlled in part by its mammary microenvironment. The mammary microenvironment is a defined location that encompasses mammary somatic stem cells, neighboring signaling cells, the basement membrane and extracellular matrix, mammary fibroblasts as well as the intercellular signals produced and received by these cells. These dynamic signals take numerous forms including growth factors, steroids, cell-cell or cell-basement membrane physical interactions. Cellular growth and differentiation of the mammary gland throughout the developmental stages are regulated by changes in these signals and interactions. The purpose of this review is to summarize current information and research regarding the role of the mammary microenvironment during normal glandular development.

Stromal matrix metalloproteinase-11 is involved in the mammary gland postnatal development

“…6,14 However, how adipocyte-related MMP-11 acts at the physiological level remains largely unknown. As stromal cells are potent mediators in the proper development and maintenance of mammary ductal morphogenesis, [15][16][17][18][19][20] we hypothetized that MMP-11 might participate in this biological process.…”

Expression of NGF, BDNF and their high-affinity receptors in ovine mammary glands during development and lactation

“…Intercellular signals of mammary microenvironment essential for normal development have been described, but they are not fully elucidated (McCave et al 2010;Brisken and Ataca 2015). Interactions between parenchyma and mammary fat pad are also demonstrated in prepubertal ewes (Hovey et al 1998), suggesting the presence of epithelial paracrine factors that would exert a positive feedback on the surrounding stroma.…”

Junctional Adhesion Molecules (JAMs) - New Players in Breast Cancer?

“…In contrast, myoepithelial cells exert functions broadly considered as tumour-suppressive. Fibroblasts are an important structural component of the extracellular environment in the normal breast, where they help control the development of the breast epithelium (McCave et al 2010). Their secretion of extracellular matrix components and cytokines has also implicated them in tumorigenic growth associated with invasive breast cancer (Orimo et al, 2005), and differences in cellular responsiveness to normal versus tumour-derived fibroblasts have been noted (Sadlonova et al, 2005).…”