Radioactive iodide uptake (RAIU) in thyroid follicular epithelial cells, mediated by the sodium iodide symporter (NIS), is the first rate-limiting step in iodide accumulation which provides a mechanism for effective radioiodide treatment for patients with thyroid cancer.
Several investigators have shown that gene transfer of NIS into a variety of cell types confers increased radioiodine uptake by up to several hundredfold that of controls in nonthyroid cancers as well as in thyroid cancer.
Sodium/iodide symporter (NIS) is a key protein in iodide transport by thyroid cells and this activity is a prerequisite for effective radioiodide treatment of thyroid cancer.
Radioiodide uptake (RAIU) in thyroid follicular epithelial cells, mediated by a plasma membrane transporter, sodium iodide symporter (NIS), provides a first step mechanism for thyroid cancer detection by radioiodide injection and effective radioiodide treatment for patients with invasive, recurrent, and/or metastatic thyroid cancers after total thyroidectomy.
The increased NIS expression and reduced PDS expression may make radioiodine therapy more effective in patients with thyroid cancer, especially when the tumors have no or low uptake of radioiodine.
The sodium/iodide symporter (NIS) gene is highly expressed in the thyroid gland and is important for the diagnosis and radioiodide therapy of differentiated thyroid cancers.
Radioiodine therapy, the most effective form of systemic radiotherapy available, is currently useful only for thyroid cancer because of thyroid-specific expression of the sodium iodide symporter (NIS).
These data showed that circulating Tg mRNA is not only a more sensitive marker of residual thyroid tissue or thyroid cancer than sTg, particularly in patients during T4 therapy and with positive antithyroglobulin antibodies, but also was more sensitive than NIS mRNA in all patients.
Apart from these therapeutic and diagnostic perspectives the availability of the NIS gene will also open new opportunities to develop sensitive and homologous diagnostic test systems to identify factors involved in autoimmune thyroid disease, evolution of goitre, adenoma and thyroid cancer as well as NIS-directed new drugs.
Retinoic acid increases sodium/iodide symporter mRNA levels in human thyroid cancer cell lines and suppresses expression of functional symporter in nontransformed FRTL-5 rat thyroid cells.