Human Mammary Epithelial Cells, Adult

Description

Human Mammary Epithelial Cells, Adult reside within the ducts and lobules of the breast and play essential roles in maintaining mammary gland function, including milk synthesis and secretion during lactation. Morphologically, these cells display cuboidal to columnar epithelial shapes and form tight junctions, contributing to the epithelial barrier. HMECs undergo dynamic remodeling in response to hormonal changes during puberty, menstrual cycles, pregnancy, lactation, and involution (post-weaning). They grow adherently in vitro and express epithelial markers such as cytokeratins (CK7, CK8/18), E-cadherin, and epithelial cell adhesion molecule (EpCAM). The key regulators include hormones (Estrogen, Prolactin) and cytokines. Genetically, HMECs generally have a stable karyotype but can accumulate mutations during malignant transformation. This hormone-responsive plasticity makes the mammary epithelium particularly susceptible to oncogenic mutations, leading to breast cancer. In normal breast architecture, mammary epithelial cells are organized within the mammary epithelium and are supported by an underlying myoepithelial cell layer, which together regulate tissue polarity, contractility, and epithelial integrity.