The Multifunctional Roles of Aquaporins in Tumors: Focusing on Metabolism, Migration, and Regulation of the Tumor Microenvironment

Aquaporins (AQPs) are transmembrane channel proteins that transport water and small solutes. Their dysregulation in cancer reveals functions beyond maintaining osmotic balance. This review summarizes that AQPs drive tumor progression through three core mechanisms: metabolic reprogramming, enhanced motility, and remodeling of the immune microenvironment. Specifically, AQP3, AQP7, and AQP9 serve as metabolic hubs for glycerol, while AQP3 and AQP8 help maintain redox homeostasis. AQP1 and AQP4 facilitate cell migration via hydrodynamic mechanisms, and AQP5 promotes invasion through signaling pathways such as Ras/NF-κB. In immune regulation, AQP9 and AQP3 modulate immune cell function by transporting metabolites, and AQP1 influences angiogenesis. Other isoforms, including AQP0, AQP2, AQP6, AQP10, and AQP11, also play roles in malignancy. Collectively, AQPs form a multifunctional network linking tumor metabolism, physical properties, and immunity, offering insights for novel diagnostic and therapeutic strategies. However, tissue-specific functions, complex regulatory mechanisms, and challenges in developing targeted therapies remain significant hurdles in translational medicine.