Molecular study of the sodium-iodide symporter (NIS): A new field in thyroidology

The active transport of iodide into the thyroid is mediated by the Na+-I- symporter (NIS), an intrinsic membrane protein. NIS plays key roles in thyroid pathophysiology as the route by which I- reaches the gland for thyroid hormone biosynthesis, and as a means for diagnostic scintigraphic imaging and for radioiodide therapy in thyroid cancer. The molecular characterization of NIS started with the isolation in 1996 of a cDNA encoding vat NIS, and has subsequently Zed to a virtually new field in thyroidology. The research reviewed in this article clearly has far-reaching implications in the areas of structure/function Of transport proteins, thyroid pathophysiology, hormone action mechanisms, cell differentiation and cancer.