NIS蛋白表达对甲状腺癌诊断及^(131)I疗效预测的相关性研究

Investigation of Value of Na^+/I^- Symporter Expression on Diagnosis of Thyroid Carcinoma and Prediction of ^(131)Ⅰ Therapeutic Effects

目的探讨钠碘同向转运体(Na+/I-symporter,NIS)蛋白表达在甲状腺癌诊断及术后131Ⅰ治疗效果预测方面的临床应用价值。方法选取我院1998~2006年病理诊断为甲状腺癌的31例患者,采用免疫组化法检测NIS蛋白在细胞中的表达部位、阳性细胞数及表达强度,并以免疫组化评分(immunohistochemical scores,I HS)表示,研究在不同病理类型甲状腺癌原发灶及转移灶中NIS蛋白的表达情况。结果阳性对照Grave病甲状腺组织中NIS蛋白呈强表达,定位于甲状腺滤泡上皮细胞基底部质膜或周边质膜;阴性对照不表达。31例甲状腺癌原发灶细胞胞浆均为NIS阳性表达,其中80.65%的患者IHS≥4分;30例转移灶中,除2例不表达外,其余为胞浆阳性。转移灶与原发灶中NIS蛋白表达具有正相关;甲状腺癌原发灶NIS蛋白表达与甲状腺癌病理类型有关,在乳头状癌(PTC)中最强,滤泡状腺癌(FTC)中次之,滤泡型乳头状癌(fvPTC)中表达较弱。结论NIS蛋白表达在甲状腺癌中主要定位于胞浆,其摄碘障碍可能主要是错误定位的结果。NIS蛋白在不同甲状腺疾病组织中的表达差异有助于甲状腺良、恶性疾病,尤其是FTC与滤泡型腺瘤的鉴别诊断,也有助于不同病理类型甲状腺癌的鉴别。原发灶NIS蛋白表达水平对预测转移灶131I疗效有帮助,NIS蛋白的免疫组化检测有广阔的临床应用前景。

Objective To study the clinical value of Na^＋/I^- symporter （NIS） expression on thyroid carcinoma diagnosis and ^131I therapeutic effects prediction. Methods Thirty-one cases of thyroid carcinomas enrolled in this hospital from 1998 to 2006 were included. Using immunohistochemical method, NIS expression location, positive cell staining and expression intensity were observed, which was calculated by immunohistochemical scores （IHS） and NIS expression level was compared between primary and metastatic carcinoma. Results NIS was over-expressed on the basolateral membrane in positive control--Grave disease tissue, and showed no staining in negative control. NIS was expressed in cytoplasm in all 31 primary carcinomas, and IHS was over or equaled to 4 in 80.65% of them. Except for 2 no staining, NIS was expressed in cytoplasm in the rest 28 metastatic carcinomas. NIS expression was related to the pathological type of thyroid carcinoma, the strongest in PTC, then FTC, and the weakest in fvPTC. NIS expression in metastatic carcinoma was related to that in primary carcinoma. Conclusion NIS is over-expressed in cytoplasm in most thyroid carcinoma, and the iodide uptaking defect is mainly due to its wrong location. It has great potential to be applied in clinic by that it can help with the differential diagnosis of benign and malignant thyroid diseases, especially between FTA and FTC, and that it can help predict the therapeutic effects of ^131I therapy following thyroid operation.