Abstract

Aquaporins (AQPs) are membrane channel proteins that regulate water and small solute transport and are widely expressed in the mammary gland. Beyond maintaining fluid balance and lipid transport, aquaporin isoforms, including AQP1, AQP3, AQP4, AQP5, and AQP7, contribute to breast cancer progression by influencing cell proliferation, migration, invasion, angiogenesis, and epithelial–mesenchymal transition. Their expression is associated with tumor aggressiveness, microenvironment remodeling, and patient prognosis. Aquaporins show promise as diagnostic and prognostic biomarkers and potential therapeutic targets, although selective clinical inhibitors remain under development.