Huang S H, Wu J C, Chang K J, Liaw K Y, Wang S M
Department of Surgery, College of Medicine, National Taiwan University, Taipei, Republic of China.
Thyroid. 1999 Nov;9(11):1095-103. doi: 10.1089/thy.1999.9.1095.
E-cadherin is a member of the cadherin family that plays a major role in epithelial integrity and tumorigenesis. Catenins are a group of cytoplasmic proteins that regulate the intracellular anchorage of cadherin and are required for the linkage between cadherin and the actin cytoskeleton. Loss of E-cadherin contributes to the pathogenesis in tumor invasion and gives a poor prognosis. In order to investigate the adhesion property of intercellular junctions in thyroid tumors, expression of alpha-,beta, and gamma-catenin should also be studied. A correlation between these molecular markers and malignancy would be useful as a preoperative diagnostic test for thyroid neoplasms. The expression of E-cadherin, alpha-, beta-, and gamma-catenin were studied in normal and neoplastic thyroid tissue by immunofluorescence microscopy and Western blot analysis. In the normal thyroid and in nodular goiter, and follicular adenoma, staining for E-cadherin, alpha-, beta-, and gamma-catenin was seen mainly at the lateral surface of epithelial cells in the follicle and the presence of these molecules was confirmed by Western blot analysis. Follicular carcinoma tissue stained positive for E-cadherin and alpha-catenin, but the results of beta- and gamma-catenin immunostaining were highly variable, with beta-catenin being absent in most follicular carcinomas (8/10) and gamma-catenin being absent in some follicular carcinomas (3/10). These results suggest that E-cadherin expression was not reduced during the pathogenesis of differentiated thyroid malignancies. Impairment of the cadherin-catenin complex at the cell junction may contribute to the malignant progression of differentiated thyroid neoplastic tissue.
E-钙黏蛋白是钙黏蛋白家族的一员，在维持上皮完整性和肿瘤发生过程中起主要作用。连环蛋白是一组细胞质蛋白，可调节钙黏蛋白的细胞内锚定，是钙黏蛋白与肌动蛋白细胞骨架之间连接所必需的。E-钙黏蛋白的缺失会导致肿瘤侵袭的发病机制，并预示着不良预后。为了研究甲状腺肿瘤细胞间连接的黏附特性，还应研究α-、β-和γ-连环蛋白的表达。这些分子标志物与恶性肿瘤之间的相关性作为甲状腺肿瘤的术前诊断测试将很有用。通过免疫荧光显微镜和蛋白质印迹分析研究了正常和肿瘤性甲状腺组织中E-钙黏蛋白、α-、β-和γ-连环蛋白的表达。在正常甲状腺、结节性甲状腺肿和滤泡性腺瘤中，E-钙黏蛋白、α-、β-和γ-连环蛋白的染色主要见于滤泡上皮细胞的侧面，蛋白质印迹分析证实了这些分子的存在。滤泡癌组织E-钙黏蛋白和α-连环蛋白染色呈阳性，但β-和γ-连环蛋白免疫染色结果差异很大，大多数滤泡癌（8/10）中β-连环蛋白缺失，部分滤泡癌（3/10）中γ-连环蛋白缺失。这些结果表明，在分化型甲状腺恶性肿瘤的发病过程中，E-钙黏蛋白的表达并未降低。细胞连接处钙黏蛋白-连环蛋白复合物的受损可能导致分化型甲状腺肿瘤组织的恶性进展。
