Cvejic D, Savin S, Petrovic I, Paunovic I, Tatic S, Krgovic K, Havelka M
Institute for the Application of Nuclear Energy, INEP, University of Belgrade, Zumun, Belgrade, Serbia.
Histopathology. 2005 Aug;47(2):209-14. doi: 10.1111/j.1365-2559.2005.02199.x.
Galectin-3 is a beta-galactoside binding protein, recently recognized as a promising molecular marker of thyroid malignancy. As reported in several studies, galectin-3 is highly expressed in papillary thyroid carcinoma, but its expression has not been investigated in papillary microcarcinoma, which is a variant of papillary thyroid carcinoma.
Using a monoclonal antibody to galectin-3 and the avidin-biotin-peroxidase complex (ABC) immunohistochemical technique, we analysed galectin-3 expression in 63 cases of papillary microcarcinoma. The results showed immunohistochemical reactivity for galectin-3 in 51 (80.9%) cases. Intensity of staining varied from strong or moderate to weak. Galectin-3 localization was mostly cytoplasmic, but also membranous or nuclear in some cells. Immunohistochemical expression of galectin-3 was not found in 12 (19.1%) cases. Most galectin-3 negative microcarcinomas (10/12) were of the non-classical type, i.e. without papillary architecture. Neither the frequency nor the intensity of a positive reaction was related to tumour size.
Galectin-3 gene is expressed at the protein level in most papillary microcarcinomas, although with slightly lower frequency than that reported for clinically evident papillary thyroid carcinoma. The presence of galectin-3 in clinically silent microcarcinomas may indicate that galectin-3 is not related to growth or aggressiveness of papillary thyroid microcarcinomas but rather plays some other role in thyroid tumour biology.
半乳糖凝集素-3是一种β-半乳糖苷结合蛋白，最近被认为是甲状腺恶性肿瘤的一个有前景的分子标志物。正如几项研究所报道的，半乳糖凝集素-3在甲状腺乳头状癌中高表达，但尚未在甲状腺微小乳头状癌（甲状腺乳头状癌的一种变体）中研究其表达情况。
我们使用抗半乳糖凝集素-3单克隆抗体和抗生物素蛋白-生物素-过氧化物酶复合物（ABC）免疫组织化学技术，分析了63例甲状腺微小乳头状癌中半乳糖凝集素-3的表达情况。结果显示，51例（80.9%）病例对半乳糖凝集素-3呈免疫组织化学反应。染色强度从强或中度到弱不等。半乳糖凝集素-3的定位主要在细胞质中，但在一些细胞中也有膜性或核性定位。12例（19.1%）病例未发现半乳糖凝集素-3的免疫组织化学表达。大多数半乳糖凝集素-3阴性的微小癌（10/12）为非经典类型，即无乳头状结构。阳性反应的频率和强度均与肿瘤大小无关。
半乳糖凝集素-3基因在大多数甲状腺微小乳头状癌中在蛋白水平表达，尽管其频率略低于临床明显的甲状腺乳头状癌所报道的频率。临床上无症状的微小癌中存在半乳糖凝集素-3可能表明，半乳糖凝集素-3与甲状腺微小乳头状癌的生长或侵袭性无关，而是在甲状腺肿瘤生物学中发挥其他作用。
