Expression and correlation of sodium iodide symporter and thyroid stimulating hormone receptor in thyroid carcinoma

Objective To investigate the expression of sodium/iodide symporter(NIS) and thyroid stimulating hormone receptor(TSHR) as well as their correlation in thyroid carcinoma. Methods mRNA levels,quantified by real-time flurescent quanti-tive polymerase chain reaction, and protein evaluated by immunohistochemistry,were examined in surgical specimens of 18 normal thyroid tissue,27 nodular goiter and 23 thyroid carcinoma samples.Results The NIS and TSHR mRNA levels of thyroid carcinoma was significantly lower than in normal thyroid tissue and nodular goiter(P0.005).There was a positive correlation between NIS and TSHR in nodular goiter and normal thyroid samples(r =0.667 and 0.551,respectively,P0.005),there was no such correlation in thyroid carcinomas.The immunohistochemistry results of thyroid cancer showed that the NIS protein mainly located in cytoplasm,and was markedly higher than normal thyroid tissue and nodular goiter(P0.05).TSHR protein mainly located in cytoplasm and cytomembrane in thyroid carcinomas,and was significantly higher when compared with normal thyroid tissues(P0.001),but had no difference with nodular goiter.Through combination analysis of NIS mRNA concentrations and NIS immunostaining scores,among the thyroid carcinomas, reduction of NIS mRNA expression but with increment of intracellular protein was markedly higher than in nodular goiter(x~2 =4.428,P =0.035).Conclusion In thyroid carcinoma,NIS and TSHR mRNA levels were low,also there was no significant correlation.