Matsuoka Taeko, Kawai Koji, Ando Satoshi, Sugita Shintaro, Kandori Shuya, Kojima Takahiro, Miyazaki Jun, Nishiyama Hiroyuki
Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba.
Department of Urology, Faculty of Medicine, University of Tsukuba, Tsukuba
Jpn J Clin Oncol. 2016 May;46(5):475-81. doi: 10.1093/jjco/hyw012. Epub 2016 Feb 24.
DNA methyltransferase 3-like plays an important role in germ cell development. The aim of this study was to analyse the DNA methyltransferase 3-like protein expression in testicular germ cell tumors.
The immunohistochemical expression of DNA methyltransferase 3-like was examined in 86 testicular germ cell tumor specimens in various clinical settings. The association between DNA methyltransferase 3-like expression and disease stage was analyzed.
DNA methyltransferase 3-like was strongly expressed in seven of the eight pure embryonal carcinomas (87.5%). Partial DNA methyltransferase 3-like expression was observed in 6 of 23 (26.1%) pure seminomas. Various degrees of DNA methyltransferase 3-like expression was observed in all four pure yolk sac tumors, of which three were prepubertal yolk sac tumors. In mixed germ cell tumors, DNA methyltransferase 3-like protein was expressed in various degrees in elements of the embryonal carcinoma (14/18, 77.8%), seminoma (4/11, 36.4%), teratoma (4/7, 57.1%) and choriocarcinoma (3/3, 100%) but not in the yolk sac tumors (0/4). When DNA methyltransferase 3-like expression was analyzed according to disease stages, it was significantly correlated with advanced seminoma rather than Stage I seminoma (46.2 vs. 0%, P = 0.019), whereas there was no significant difference in the DNA methyltransferase 3-like-positive proportion between Stage I and advanced disease in the mixed germ cell tumors.
Our findings suggest that DNA methyltransferase 3-like protein may play roles not only in the development of embryonal carcinoma but also in the development of advanced pure seminoma and pure yolk sac tumor.
DNA甲基转移酶3样蛋白在生殖细胞发育中起重要作用。本研究旨在分析睾丸生殖细胞肿瘤中DNA甲基转移酶3样蛋白的表达情况。
检测86例不同临床分期的睾丸生殖细胞肿瘤标本中DNA甲基转移酶3样蛋白的免疫组化表达情况，并分析其表达与疾病分期的关系。
在8例纯胚胎癌中有7例（87.5%）DNA甲基转移酶3样蛋白呈强表达。23例纯精原细胞瘤中有6例（26.1%）出现部分DNA甲基转移酶3样蛋白表达。4例纯卵黄囊瘤均出现不同程度的DNA甲基转移酶3样蛋白表达，其中3例为青春期前卵黄囊瘤。在混合性生殖细胞肿瘤中，胚胎癌成分（14/18，77.8%）、精原细胞瘤成分（4/11，36.4%）、畸胎瘤成分（4/7，57.1%）和绒毛膜癌成分（3/3，100%）中DNA甲基转移酶3样蛋白均有不同程度表达，而卵黄囊瘤成分中未出现表达（0/4）。根据疾病分期分析DNA甲基转移酶3样蛋白表达情况时，其与晚期精原细胞瘤显著相关，而非I期精原细胞瘤（46.2%对0%，P = 0.019），而在混合性生殖细胞肿瘤中，I期和晚期疾病的DNA甲基转移酶3样蛋白阳性比例无显著差异。
我们的研究结果表明，DNA甲基转移酶3样蛋白可能不仅在胚胎癌的发生中起作用，还在晚期纯精原细胞瘤和纯卵黄囊瘤的发生中起作用。
