Key roles of aquaporins in tumor biology

• Aquaporins are channels that facilitate the flow of water across the cell membrane.
• Most tumors have high levels of aquaporin expression.
• Aquaporins have roles in tumor growth, edema, angiogenesis and tumor cell migration.
• Aquaporin inhibitors or downregulators may be novel anti-cancer drugs.

Aquaporins are protein channels that facilitate the flow of water across plasma cell membranes in response to osmotic gradients. This review summarizes the evidence that aquaporins play key roles in tumor biology including tumor-associated edema, tumor cell migration, tumor proliferation and tumor angiogenesis. Aquaporin inhibitors may thus be a novel class of anti-tumor agents. However, attempts to produce small molecule aquaporin inhibitors have been largely unsuccessful. Recently, monoclonal human IgG antibodies against extracellular aquaporin-4 domains have become available and could be engineered to kill aquaporin-4 over-expressing cells in the malignant brain tumor glioblastoma. We conclude this review by discussing future directions in aquaporin tumor research. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.

Figure optionsDownload high-quality image (173 K)Download as PowerPoint slide