Study of potential inhibitors of thyroid iodide uptake by using CHO cells stably expressing the human sodium/iodide symporter (hNIS) protein

Background : Thyroid gland is highly dependent on dietary intake of iodine for normal function, so it is particularly subjected to “endocrine disruptor” action. The human sodium/iodide symporter (hNIS) is an integral plasma membrane glycoprotein mediating the active transport of iodide into thyroid follicular cells, a crucial step for thyroid hormone biosynthesis. Beyond to perchlorate and thyocianate ions a few other inhibitors of iodide uptake have been described. Aim : The aim of this study was to investigate if 10 substances usually used as drugs in clinical practice were able to inhibit NIS-mediated iodide uptake in vitro. Materials and methods : A CHO cell line stably expressing hNIS was used to test any inhibition of NIS-mediated iodide uptake exerted by drugs. Perchlorate and thyocianate ions were used as positive controls. Results : None of the analyzed substances was able to significantly inhibit iodide uptake in our system. As we expected, perchlorate and thyocianate ions were able to inhibit iodide uptake in a dose-dependent manner. Conclusions : In conclusion, we carried out an in vitro assay to evaluate the potential inhibitory effect of common drugs on NIS-mediated iodide uptake by using CHO-hNIS cells. None of the analyzed substances was able to inhibit iodide uptake; only perchlorate and thyocianate were able to inhibit iodide uptake in a dose-dependent manner.