尤因肉瘤是一种未分化的小圆细胞肉瘤。尽管对EWSR1-ETS融合蛋白如EWSR1-FLI1进行分子检测可以明确诊断,如果无法进行分子诊断,则可能会出现严重的混乱。基于常规免疫组织化学标记CD99的诊断由于其在形态模拟物中的丰富表达而不可靠。鉴定尤文肉瘤的新诊断免疫组织化学标记物,我们在768个肿瘤中进行了比较表达分析,这些肿瘤代表21个实体,包括尤文样肉瘤,这证实了CIC-DUX4-,BCOR-CCNB3-,EWSR1-NFATc2-,和EWSR1-ETS易位肉瘤是不同的实体,并显示ATP1A1,BCL11B,和GLG1构成尤文肉瘤的特异性标志物。通过免疫组织化学验证了它们的高表达,并证明依赖于EWSR1-FLI1与高活性近端超增强子的结合。在包含174个样品的组织微阵列中的自动截点发现和组合测试表明,检测到高BCL11B和/或GLG1表达足以达到尤因肉瘤的96%特异性。虽然88%的受测尤因样肉瘤表现出强烈的CD99免疫反应性,没有一个显示出强的BCL11B-和GLG1-免疫反应性。总的来说,我们发现ATP1A1,BCL11B,GLG1是EWSR1-FLI1靶标,其中BCL11B和GLG1提供了一个快速的,简单,以及通过免疫组织化学诊断尤文肉瘤的经济有效方法。这些标记物可以显著减少误诊患者的数量,从而改善患者护理。
Ewing sarcoma is an undifferentiated small-round-cell sarcoma. Although molecular detection of pathognomonic EWSR1-ETS fusions such as EWSR1-FLI1 enables definitive diagnosis, substantial confusion can arise if molecular diagnostics are unavailable. Diagnosis based on the conventional immunohistochemical marker CD99 is unreliable due to its abundant expression in morphological mimics. To identify novel diagnostic immunohistochemical markers for Ewing sarcoma, we performed comparative expression analyses in 768 tumors representing 21 entities including Ewing-like sarcomas, which confirmed that CIC-DUX4-, BCOR-CCNB3-, EWSR1-NFATc2-, and EWSR1-ETS-translocated sarcomas are distinct entities, and revealed that ATP1A1, BCL11B, and
GLG1 constitute specific markers for Ewing sarcoma. Their high expression was validated by immunohistochemistry and proved to depend on EWSR1-FLI1-binding to highly active proximal super-enhancers. Automated cut-off-finding and combination-testing in a tissue-microarray comprising 174 samples demonstrated that detection of high BCL11B and/or
GLG1 expression is sufficient to reach 96% specificity for Ewing sarcoma. While 88% of tested Ewing-like sarcomas displayed strong CD99-immunoreactivity, none displayed combined strong BCL11B- and
GLG1-immunoreactivity. Collectively, we show that ATP1A1, BCL11B, and
GLG1 are EWSR1-FLI1 targets, of which BCL11B and
GLG1 offer a fast, simple, and cost-efficient way to diagnose Ewing sarcoma by immunohistochemistry. These markers may significantly reduce the number of misdiagnosed patients, and thus improve patient care.