Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland.
Mod Pathol. 2011 Jun;24(6):829-35. doi: 10.1038/modpathol.2011.6.
Melanoma-associated gene C2 (MAGEC2) is a recently identified cancer testis antigen expressed in normal testicular and placental tissue. It has been detected in some human carcinomas, but its expression in primary testicular germ cell tumors is unknown. Immunohistochemistry was used to study MAGEC2 protein in 325 primary testicular germ cell tumors, including 94 mixed germ cell tumors. Seminomatous and non-seminomatous components were separately arranged and evaluated on tissue microarrays. MAGEC2 expression was compared with POU5F1 (OCT3/4), SOX2, SOX17, KIT and TNFRSF8 (CD30). The mouse monoclonal anti-MAGEC2 antibody (clone LX-CT10.5) revealed a nuclear MAGEC2 expression with little or no background staining. MAGEC2 expression was found in 238 of 254 seminomas (94%), but not in embryonal carcinomas (n=89). POU5F1 (OCT3/4) was positive in 97% of seminomas and all embryonal carcinomas. In contrast, KIT was positive in 94% of seminoma but also in 8% of embryonal carcinomas. TNFRSF8 (CD30) and SOX2 were negative in seminoma and positive in embryonal carcinoma (96 and 90%, respectively). SOX17 was positive in 94% of seminoma and negative in embryonal carcinoma. We conclude that MAGEC2 allows a reliable distinction of seminoma from embryonal carcinomas. Therefore, MAGEC2 represents an additional tool for the differential diagnosis of testicular germ cell tumors.
黑色素瘤相关基因 C2（MAGEC2）是一种新发现的癌症睾丸抗原，在正常睾丸和胎盘组织中表达。它已在一些人类癌中检测到，但在原发性睾丸生殖细胞肿瘤中的表达尚不清楚。免疫组织化学法用于研究 325 例原发性睾丸生殖细胞肿瘤中的 MAGEC2 蛋白，包括 94 例混合性生殖细胞肿瘤。在组织微阵列上分别排列和评估精原细胞瘤和非精原细胞瘤成分。比较 MAGEC2 表达与 POU5F1（OCT3/4）、SOX2、SOX17、KIT 和 TNFRSF8（CD30）。鼠单克隆抗 MAGEC2 抗体（克隆 LX-CT10.5）显示核 MAGEC2 表达，背景染色很少或没有。在 254 例精原细胞瘤中有 238 例（94%）表达 MAGEC2，但在胚胎癌中无表达（n=89）。POU5F1（OCT3/4）在 97%的精原细胞瘤和所有胚胎癌中均为阳性。相比之下，KIT 在 94%的精原细胞瘤中阳性，但在 8%的胚胎癌中阳性。TNFRSF8（CD30）和 SOX2 在精原细胞瘤和胚胎癌中均为阴性（分别为 96%和 90%）。SOX17 在 94%的精原细胞瘤中阳性，在胚胎癌中阴性。我们得出结论，MAGEC2 可可靠地区分精原细胞瘤和胚胎癌。因此，MAGEC2 是睾丸生殖细胞肿瘤鉴别诊断的另一种工具。
