Sodium/iodide symporter (NIS) and pendrin are expressed differently in hot and cold nodules of thyroid toxic multinodular goiter

Abstract

Objective: The expression of two iodide transporters, the sodium/iodide symporter (NIS) and pendrin, was analyzed in thyroid tissues of patients with toxic multinodular goiter (TMNG) and non-toxic multinodular goiter (MNG). Methods: The levels of NIS and pendrin proteins were analyzed in total protein extracts from nodular and non-nodular tissues by Western blot. Results: In tissue samples from TMNG, we found an increased expression of NIS (2.5-fold) in the hot nodules, and similar levels between cold nodules and non-nodular tissues. In contrast, the levels of pendrin were slightly increased in both hot and cold nodules from TMNG, and decreased (about twofold) in cold nodules from MNG. We also noticed that there was no relationship between NIS and pendrin expression.Conclusions: Our data demonstrate that hot nodules from TMNG express a higher number of iodide transporters (mainly NIS), whereas cold nodules from TMNG, but not from MNG, show levels of the two proteins comparable with normal tissue, suggesting a role in vivo of TSH in maintaining the expression of NIS and pendrin protein in normal thyroid tissue. Finally, different mechanisms are involved in the regulation of NIS and pendrin expression.

Pendrin immunoreactivity in the gill epithelium of a euryhaline elasmobranch

“…Immunoblotting with an anti-human pendrin antibody demonstrated the presence of an ϳ144-kDa protein in gill membrane enrichments from Atlantic stingrays (Fig. 1), a molecular mass that is slightly greater than the reported size of 95-115 kDa for pendrin in mammals (24,25,27,31). The difference in size may indicate that the pendrin-like protein in elasmobranchs is composed of more amino acids and/or that the protein is heavily glycosylated in elasmobranchs compared with mammals.…”

Stimulation of iodide uptake by human chorionic gonadotropin in FRTL-5 cells: effects on sodium/iodide symporter gene and protein expression

“…Electroblotting to a Hybond ECL-polyvinylidene difluoride nitrocellulose membrane (Amersham Pharmacia Biotech) was performed for 2 h at 12 5 mA using a Mini TRANS BLOT electroblotting system (Bio-Rad Laboratories S.r.l.). After 2 h of blocking at room temperature with TTBS/milk (Tris-buffered saline, 1% Tween 20, and 5% non-fat dry milk), the membrane was incubated overnight at 4 8C in TTBS/milk with a 1/1000 dilution of affinity-purified rabbit anti-NIS (18,19) polyclonal antibody or a 1/5000 dilution of mouse monoclonal anti-human b-actin antibody (Sigma-Aldrich S.r.l.). After one 5-min and two 5-min washes in TTBS, the membrane was incubated with a 1/2000 dilution of horseradish peroxidase-conjugated anti-rabbit or anti-mouse antibody (Amersham Pharmacia Biotech) in TTBS/milk.…”

Redifferentiation Therapy in Thyroid Cancer

“…These tumors lack the ability to uptake iodide and are thereby refractory to radioiodine therapy. (62,63) Investigators have tried to restore NIS expression in thyroid cancer cells. (9,23,57) There are two remarkable advances in this field i.e.…”