Characterization of small-molecule inhibitors of the sodium iodide symporter

The sodium/iodide symporter (NIS) mediates the active transport of iodide from the bloodstream into thyrocytes. NIS function is strategic for the diagnosis and treatment of various thyroid diseases. In addition, a promising anti-cancer strategy based on targeted NIS gene transfer in non-thyroidal cells is currently developed. However, only little information is available concerning the molecular mechanism of NIS-mediated iodide translocation. Ten small molecules have recently been identified using a high-throughput screening method for their inhibitory effect on iodide uptake of NIS-expressing mammalian cells. In the present study, we analyzed these compounds for their rapid and reversible effects on the iodide-induced current in NIS-expressing Xenopus oocytes. Four molecules almost completely inhibited the iodide-induced current; for three of them the effect was irreversible, for one compound the initial current could be fully re-established after washout. Three molecules showed a rapid inhibitory effect of about 75%, half of which was reversible. Another three compounds inhibited the iodide-induced current from 10 to 50%. Some molecules altered the membrane conductance by themselves, i.e. in the absence of iodide. For one of these molecules the observed effect was also found in water-injected oocytes whereas for some others the iodide-independent effect was associated with NIS expression. The tested molecules show a surprisingly high variability in their possible mode of action, and thus are promising tools for further functional characterization of NIS on a molecular level, and they could be useful for medical applications.

• Fecha de publicación: 2009
• Institución: Universidad del Rosario
• Repositorio: Repositorio EdocUR - U. Rosario
• Idioma: eng
• OAI Identifier: oai:repository.urosario.edu.co:10336/27355
• Acceso en línea: https://doi.org/10.1677/JOE-08-0246; https://repository.urosario.edu.co/handle/10336/27355
• Palabra clave: Symporters; antagonists & inhibitors; Molecular structure; Drug evaluation; preclinical; Oocytes; metabolism
• License: Abierto (Texto Completo)