The mammary gland is dynamically remodelled during its postnatal
development and the reproductive cycles. This inherent plasticity has
been suggested to increase the susceptibility of the organ to
carcinogenesis. Morphological changes in the mammary epithelium involve
cell proliferation, differentiation, apoptosis, and migration which, in
turn, are affected by cell adhesion to the extracellular matrix (ECM).
Integrin adhesion receptors function in the sensing of the biochemical
composition, patterning and mechanical properties of the ECM surrounding
the cells, and strongly influence cell fate. This review aims to
summarize the existing literature on how different aspects of
integrin-mediated adhesion and mechanosensing, including ECM
composition; stiffness and topography; integrin expression patterns;
focal adhesion assembly; dynamic regulation of the actin cytoskeleton;
and nuclear mechanotransduction affect mammary gland development,
function and homeostasis. As the mechanical properties of a complex
tissue environment are challenging to replicate in vitro, emphasis has
been placed on studies conducted in vivo or using organoid models.
Outright, these studies indicate that mechanosensing also contributes to
the regulation of mammary gland morphogenesis in multiple ways.