Netea-Maier Romana T, Hunsucker Stephen W, Hoevenaars Brigiet M, Helmke Steve M, Slootweg Pieter J, Hermus Ad R, Haugen Bryan R, Duncan Mark W
Department of Endocrinology, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
Cancer Res. 2008 Mar 1;68(5):1572-80. doi: 10.1158/0008-5472.CAN-07-5020.
Distinguishing between benign follicular thyroid adenoma (FTA) and malignant follicular thyroid carcinoma (FTC) by cytologic features alone is not possible. Molecular markers may aid distinguishing FTA from FTC in patients with indeterminate cytology. The aim of this study is to define protein abundance differences between FTC from FTA through a discovery (proteomics) and validation (immunohistochemistry) approach. Difference gel electrophoresis (DIGE) and peptide mass fingerprinting were performed on protein extracts from five patients with FTC and compared with six patients with FTA. Individual gel comparisons (i.e., each FTC extract versus FTA pool) were also performed for the five FTC patients. Immunohistochemical validation studies were performed on three of the identified proteins. Based on DIGE images, 680 protein spots were matched on individual gels. Of these, 102 spots showed statistically significant differences in abundance between FTC and FTA in the individual gel analyses and were therefore studied further. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify 54 of these protein spots. Three candidates involved in protein folding (heat shock protein gp96, protein disulfide isomerase A3, and calreticulin) were studied by immunohistochemistry. Moderate calreticulin immunohistochemical staining was the best single marker with a high negative predictive value (88%); combining all three markers (any marker less than moderate staining) had the best positive predictive value (75%) while still retaining a good negative predictive value (68%). With DIGE, we identified 54 proteins differentially abundant between FTC and FTA. Three of these were validated by immunohistochemistry. These findings provide further insights into the diagnosis, prognosis, and pathophysiology of follicular-derived thyroid neoplasms.
仅通过细胞学特征来区分良性滤泡性甲状腺腺瘤（FTA）和恶性滤泡性甲状腺癌（FTC）是不可能的。分子标志物可能有助于在细胞学结果不确定的患者中区分FTA和FTC。本研究的目的是通过探索性（蛋白质组学）和验证性（免疫组织化学）方法来确定FTC与FTA之间的蛋白质丰度差异。对5例FTC患者的蛋白质提取物进行了差异凝胶电泳（DIGE）和肽质量指纹分析，并与6例FTA患者进行了比较。还对这5例FTC患者进行了个体凝胶比较（即每个FTC提取物与FTA混合样本）。对其中3种已鉴定的蛋白质进行了免疫组织化学验证研究。基于DIGE图像，在个体凝胶上匹配了680个蛋白质斑点。其中，102个斑点在个体凝胶分析中显示出FTC和FTA之间在丰度上有统计学显著差异，因此进行了进一步研究。使用基质辅助激光解吸/电离飞行时间质谱法鉴定了其中54个蛋白质斑点。通过免疫组织化学研究了3种参与蛋白质折叠的候选蛋白（热休克蛋白gp96、蛋白质二硫键异构酶A3和钙网蛋白）。中等强度的钙网蛋白免疫组织化学染色是最佳的单一标志物，具有较高的阴性预测值（88%）；联合使用所有3种标志物（任何标志物染色强度低于中等）具有最佳的阳性预测值（75%），同时仍保留良好的阴性预测值（68%）。通过DIGE，我们鉴定出54种在FTC和FTA之间丰度有差异的蛋白质。其中3种通过免疫组织化学得到了验证。这些发现为滤泡性甲状腺肿瘤的诊断、预后和病理生理学提供了进一步的见解。
