Infrequent SMARCB1/INI1 gene alteration in epithelioid sarcoma: a useful tool in distinguishing epithelioid sarcoma from malignant rhabdoid tumor
Infrequent SMARCB1/INI1 gene alteration in epithelioid sarcoma: a useful tool in distinguishing epithelioid sarcoma from malignant rhabdoid tumor
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DOI：
10.1016/j.humpath.2008.08.007
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发表时间：
2009-03-01
期刊：
影响因子：
3.3
通讯作者：
Tsuneyoshi, Masazumi
中科院分区：
文献类型：
--
作者：
Kohashi, Kenichi;Izumi, Teiyu;Tsuneyoshi, Masazumi
SMARCB 1/INI 1蛋白表达的缺失被认为可用于确认恶性横纹肌样瘤的组织学诊断。然而，SMARCB 1/INI 1蛋白表达的丧失最近也在其他肿瘤中报道，包括少数上皮样肉瘤病例。此外，近端型上皮样肉瘤和恶性横纹肌样瘤之间的组织病理学差异还没有最终确定。我们分析了SMARCB 1/INI 1蛋白在54例上皮样肉瘤（近端型，25例;远端型，29例）中的表达，并检测了SMARCB 1/INI 1基因在蛋白表达缺失的病例中的改变。我们发现19例（76.0%）近端型上皮样肉瘤和27例（93.1%）远端型上皮样肉瘤显示SMARCB 1/INI 1蛋白表达缺失。对39例蛋白表达缺失的病例进行分析，发现4例（10.3%）SMARCB 1/INI 1基因在DNA水平发生改变（纯合缺失，2例; 1或2 bp缺失，2例），可能导致基因产物的缺失，所有4例均为近端型上皮样肉瘤。因此，上皮样肉瘤与SMARCB 1/INI 1蛋白表达丢失的高频率相关，与恶性横纹肌样肿瘤相似。然而，SMARCB 1/INI 1基因改变的频率在近端型上皮样肉瘤的DNA水平上显着低于恶性横纹肌样肿瘤。此外，恶性横纹肌样瘤患者的预后明显差于近端型上皮样肉瘤患者（P = 0.001）。因此，近端型上皮样肉瘤和恶性横纹肌样瘤被认为是独特的肿瘤方面的SMARCB 1/INI 1蛋白表达的损失的机制。SMARCB 1/INI 1基因的改变分析可能是一个有用的诊断工具，以区分近端型上皮样肉瘤恶性横纹肌样瘤。(c)2009 Elsevier Inc. All rights reserved.
Loss of SMARCB1/INI1 protein expression is considered useful for confirming a histologic diagnosis of malignant rhabdoid tumor. However, loss of SMARCB1/INI1 protein expression has recently been reported in other tumors as well, including a few cases of epithelioid sarcoma. In addition, the histopathologic differences between proximal-type epithelioid sarcoma and malignant rhabdoid tumor have not been conclusively defined. We analyzed SMARCB1/INI1 protein expression in 54 epithelioid sarcoma (proximal-type, 25; distal-type, 29) and examined alterations of the SMARCB1/INI1 gene in the cases lacking protein expression. We found that 19 (76.0%) proximal-type epithelioid sarcoma and 27 (93.1%) distal-type epithelioid sarcoma showed loss of SMARCB1/INI1 protein expression. Analysis of 39 cases with loss of protein expression revealed 4 cases (10.3%) with SMARCB1/INI1 gene alterations at the DNA level (homozygous deletion, 2; 1- or 2-bp deletion, 2) that could have induced the loss of gene products, and all 4 of these were proximal-type epithelioid sarcoma. Epithelioid sarcoma was thus associated with a high frequency of loss of SMARCB1/INI1 protein expression similar to that in malignant rhabdoid tumor. However, the frequency of SMARCB1/INI1 gene alteration at the DNA level in proximal-type epithelioid sarcoma was significantly lower than that in malignant rhabdoid tumor. In addition, the prognosis of patients with malignant rhabdoid tumor is significantly worse than that of patients with proximal-type epithelioid sarcoma (P = .001). Therefore, proximal-type epithelioid sarcoma and malignant rhabdoid tumor are suggested to be distinctive tumors with respect to the mechanism of the loss of SMARCB1/INI1 protein expression. Analysis of alterations in the SMARCB1/INI1 gene may thus be a useful diagnostic tool to distinguish proximal-type epithelioid sarcoma from malignant rhabdoid tumor. (c) 2009 Elsevier Inc. All rights reserved.