Ominato Jun, Fukuchi Takeo, Sato Ayako, Yamaguchi Naoyuki, Kobayashi Kazue, Cho Hiroyuki, Oyama Tokuhide, Ajioka Yoichi
Division of Molecular and Diagnostic Pathology.
Division of Ophthalmology and Visual Science, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
Appl Immunohistochem Mol Morphol. 2018 Oct;26(9):658-663. doi: 10.1097/PAI.0000000000000505.
GNAQ and GNA11 mutations are thought to be important for the tumorigenesis of uveal melanoma. Although previous studies have reported on mutation rates in cases of uveal melanoma, presently, no such report for the Japanese population exists. In this study, we examined the frequency of GNAQ and GNA11 somatic mutations in cases of uveal melanoma in Japan and their relationship with clinicopathologic features or Ki-67-positive cell rates (Ki-67 labeling index: Ki-67 LI) using immunofluorescence methods. The study involved 19 cases of uveal melanoma. We extracted the template DNA from formalin-fixed, paraffin-embedded specimens using a DNA extraction kit. We amplified the DNA sequences of GNAQ and GNA11 using polymerase chain reaction and analyzed mutations by direct sequencing. We evaluated Ki-67 LI using immunofluorescence methods. The frequencies of GNAQ and GNA11 somatic mutations were 26.3% (5/19) and 31.6% (6/19), respectively. The GNAQ and GNA11 mutations were mutually exclusive, as indicated in previous reports. The frequency of GNA11 mutations was significantly higher in epithelioid cells; however, no significant association between GNAQ mutations and cell type was evident, and there was no significant difference in Ki-67 LI between the mutation-positive and mutation-negative tumors. GNAQ and GNA11 mutations were identified in cases of uveal melanoma in Japan, although at lower frequencies than in white counterparts. The mutation frequency of GNA11 was significantly higher in epithelioid cells.
GNAQ和GNA11突变被认为对葡萄膜黑色素瘤的肿瘤发生很重要。尽管先前的研究报告了葡萄膜黑色素瘤病例的突变率，但目前尚无针对日本人群的此类报告。在本研究中，我们使用免疫荧光方法检测了日本葡萄膜黑色素瘤病例中GNAQ和GNA11体细胞突变的频率及其与临床病理特征或Ki-67阳性细胞率（Ki-67标记指数：Ki-67 LI）的关系。该研究纳入了19例葡萄膜黑色素瘤病例。我们使用DNA提取试剂盒从福尔马林固定、石蜡包埋的标本中提取模板DNA。我们使用聚合酶链反应扩增GNAQ和GNA11的DNA序列，并通过直接测序分析突变。我们使用免疫荧光方法评估Ki-67 LI。GNAQ和GNA11体细胞突变的频率分别为26.3%（5/19）和31.6%（6/19）。如先前报告所示，GNAQ和GNA11突变相互排斥。GNA11突变在上皮样细胞中的频率显著更高；然而，GNAQ突变与细胞类型之间无明显关联，且突变阳性和突变阴性肿瘤之间的Ki-67 LI无显著差异。在日本的葡萄膜黑色素瘤病例中发现了GNAQ和GNA11突变，尽管其频率低于白人患者。GNA11的突变频率在上皮样细胞中显著更高。
