Santos Giscle Caravina, Carvalho Kátia Candido, Falzoni Roberto, Simoes Ana Carolina Q, Rocha Rafael Malagoli, Lopes Ademar, Vassallo Jose, Reis Luiz Fernando Lima, Soares Fernando Augusto, da Cunha Isabela Werneck
Department of Pathology, Hospital do Cancer de Barretos, Barretos, SP, Brazil.
Mod Pathol. 2009 Oct;22(10):1321-7. doi: 10.1038/modpathol.2009.99. Epub 2009 Aug 7.
Glial fibrillary acidic protein (GFAP) is a member of the intermediary filament protein family. It is an important component of astrocytes and a known diagnostic marker of glial differentiation. GFAP is expressed in other neural tumors and pleomorphic adenoma and, less frequently, in cartilage tumors, chordomas, and soft tissue myoepitheliomas. The aim of this study was to evaluate the role of GFAP and its reliability in nonglial tumors as an immunohistochemical marker. We evaluated GFAP gene and protein expression using Q-PCR and immunohistochemistry, respectively, in 81 and 387 cases of soft tissue, bone tumors, and salivary pleomorphic adenomas. Immunohistochemistry staining for GFAP was observed in all osteosarcomas (8 cases), all pleomorphic adenomas (7 cases), in 5 of 6 soft tissue myoepitheliomas, and in 21 of 76 chondrosarcomas. By Q-PCR, GFAP was highly expressed in pleomorphic adenomas and, to a lesser extent, chondrosarcomas, soft tissue myoepitheliomas, and chondroblastic osteosarcomas. The results that we obtained by immunohistochemistry and Q-PCR were well correlated. GFAP is a potential marker for tumors with cartilaginous differentiation, supported by evidence that GFAP is expressed in certain cases of myoepithelial tumors by immunohistochemistry, including soft tissue myoepitheliomas, which are related to cartilaginous differentiation. These findings contribute significantly to the diagnosis of soft tissue myoepitheliomas with cartilaginous differentiation and chondroblastic osteosarcoma in mesenchymal tumors.
胶质纤维酸性蛋白（GFAP）是中间丝蛋白家族的成员。它是星形胶质细胞的重要组成部分，也是胶质细胞分化的已知诊断标志物。GFAP在其他神经肿瘤和多形性腺瘤中表达，在软骨肿瘤、脊索瘤和软组织肌上皮瘤中表达较少。本研究的目的是评估GFAP在非胶质肿瘤中作为免疫组化标志物的作用及其可靠性。我们分别使用Q-PCR和免疫组化方法评估了81例软组织、骨肿瘤和唾液腺多形性腺瘤以及387例病例中的GFAP基因和蛋白表达。在所有骨肉瘤（8例）、所有多形性腺瘤（7例）、6例软组织肌上皮瘤中的5例以及76例软骨肉瘤中的21例中观察到了GFAP的免疫组化染色。通过Q-PCR检测，GFAP在多形性腺瘤中高表达，在软骨肉瘤、软组织肌上皮瘤和成软骨细胞性骨肉瘤中表达程度较低。我们通过免疫组化和Q-PCR获得的结果具有良好的相关性。GFAP是具有软骨分化肿瘤的潜在标志物，免疫组化显示GFAP在某些肌上皮肿瘤病例中表达，包括与软骨分化相关的软组织肌上皮瘤，这为该结论提供了证据。这些发现对间叶性肿瘤中具有软骨分化的软组织肌上皮瘤和成软骨细胞性骨肉瘤的诊断有重要贡献。
