Cell Shape and Integrin Signaling Regulate the Differentiation State of Mammary Epithelial Cells
When they are cultured on a reconstituted basement membrane gel, mammary epithelial cells round-up, aggregate, form cell-cell junctions, and undergo an apical/basal polarization that ultimately produces a central lumen. The resulting three-dimensional ‘mammospheres’ closely resemble lactational alveoli in vivo and they fully differentiate when they are maintained in an appropriate mileau of lactogenic hormones. Specifically, the cells express milk protein genes, package the products in secretory vesicles, transport the vesicles to the apical cell surface, and release the products into the central lumen. Therefore, dynamic and reciprocal interactions between epithelial cells and the surrounding basement membrane are key regulators of phenotypic change in the developing mammary gland (1, 2, 3, 4).
KeywordsBasement Membrane Lactogenic Hormone Mammary Epithelial Cell Differentiation Medium Central Lumen
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