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.
Elucidation of the regulation of human sodium-iodide symporter (hNIS) gene expression is critical to understanding its effects on iodide concentration abilities of thyroid and thyroid carcinomas.
Expression of the Na+/I- symporter (NIS) gene was investigated by RT-PCR in a selected series of 26 primary thyroid carcinomas (19 papillary, 5 follicular, and 2 anaplastic).
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.
Study of NIS gene expression in the metastatic lymph nodes, therefore, may provide useful information in the management of patients with thyroid carcinoma.
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.
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).
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.
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.
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.
Deficient CRE-like sequence binding protein(s) that bind to the hNUE in normal thyroid cells may be responsible for reduced NIS gene expression in some thyroid carcinomas.
A mammalian NIS expression vector was constructed and used to generate six stable NIS-expressing cancer cell lines (three derived from thyroid carcinoma, two from colon carcinoma, one from glioblastoma).
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.
Our results have indicated for the first time that reduced levels of CREB expression are a feature of thyroid carcinomas, and confirm that different factors are likely to modulate NIS expression.
NIS is a target for radioiodide imaging and therapeutic ablation of thyroid carcinomas and has the potential for similar use in breast cancer treatment.