甲状腺癌钠／碘转运蛋白及促甲状腺激素受体表达及相关性研究

目的研究甲状腺癌钠／碘转运蛋白（NIS）和促甲状腺激素受体（TSHR）的表达特征及其相关性。方法收集正常甲状腺组织52例、结节性甲状腺肿58例和甲状腺癌56例，通过荧光定量分析和免疫组化法研究NIS和TSHR的表达。结果甲状腺癌NISmRNA和TSHRmRNA的表达显著低于正常甲状腺组织和结节性甲状腺肿（P〈0．001），正常甲状腺组织和结节性甲状腺肿NIS和TSHR的表达呈正相关（r=0．758和0．653，P=0．006和0．005），而在甲状腺癌中无显著相关性（r=0．389，P=0．136）。免疫组化结果表明甲状腺癌NIS阳性产物主要定位于细胞质，TSHR阳性产物定位于细胞质和细胞膜。甲状腺癌和结节性甲状腺肿NIS及TSHR蛋白表达显著高于正常甲状腺（P〈0．001）；同正常甲状腺组织相比，甲状腺癌NIS及TSHRmRNA表达下降同时伴有细胞质蛋白表达升高的分别为45例和47例（80％，85％）。结论甲状腺癌NIS和TSHR表达具有非相关性以及在转录和翻译水平上具有矛盾性，NIS蛋白非功能定位于细胞质，因而不能发挥正常的运输及聚碘功能。

Expression of sodium/iodide symporter and thyroid stimulating hormone receptor in thyroid

Objective To investigate the expression of sodimn/iodide symporter （NIS） and thyroid stimulating hormone receptor （TSHR）in human thyroid carcinoma. Methods Samples of normal thyroid tissues （52 cases）, nodular goiters （58 cases） and thyroid carcinoma （56 cases） were collected to examine the expression of NIS and TSHR by quantitative fluorescence analysis and immunohistoehemistry. Results NIS and TSHR mRNA level were significantly lower in thyroid carcinoma than in normal thyroid tissues and nodular goiters （P 〈 0.001 ）. In addition, there was a positive correlation between NIS and TSHR in normal thyroid tissues and nodular goiters （ r = 0. 758 and 0. 653 respectively, P = 0. 006 and 0. 005 respectively） , whereas there was no such correlation in thyroid carcinoma（r = 0. 389, P = 0. 136）. Immunohistochemistry results showed NIS protein of thyroid cancer was mainly located in cytoplasm, and TSHR protein was mainly located in cytoplasm as well as cytomembrane. The expression of NIS and TSHR protein was markedly higher in thyroid carcinoma and nodular goiter than in normal thyroid tissues（P 〈 0. 001 ）. Combined analysis of mRNA concentration and immunostaining scores showed that reduction of NIS and TSHR mRNA expression with increasement of intracellular protein was found in 80% （45/56） and 85% （47/56） of the samples in thyroid carcinomas when compared with normal tissues. Conclusions In thyroid carcinomas, there is expressed contradiction and non-correlation between NIS and TSHR expression. NIS protein is mainly located in cytoplasm and lack the ability of iodine transportation and absorption.