Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, PA, USA.
Am J Clin Pathol. 2013 Jun;139(6):765-70. doi: 10.1309/AJCPBSLP8XHSWLOW.
Microsatellite instability (MSI) contributes to the tumorigenesis of upper urinary tract urothelial carcinomas (UUT-UCs). In this study, we first used MLH1 and MSH2 immunohistochemistry to identify patients with loss of expression of either or both of these proteins in 132 UUT-UCs. We found a total loss of MSH2 expression in 4 patients. MSI was evaluated using 5 markers in these 4 cases. All of the tumors had high MSI (MSI-H) status. Trans-activation responsive RNA-binding protein 2, an integral component of DICER1-containing complex, was a putative target of DNA mismatch repair deficiency. Truncating mutation has been identified in gastrointestinal cancers with MSI. No previous study has evaluated the mutation status of this gene in MSI UUT-UCs. In this study, we analyze the mutation of TARBP2 in MSI-H UUT-UCs with reverse transcription polymerase chain reaction. No truncating mutations were identified in the MSI-H UUT-UCs.
微卫星不稳定性（MSI）有助于上尿路上皮癌（UUT-UC）的肿瘤发生。在这项研究中，我们首先使用 MLH1 和 MSH2 免疫组织化学在 132 例 UUT-UC 中鉴定出丢失表达这些蛋白中的任一种或两种蛋白的患者。我们发现 4 例患者的 MSH2 表达完全缺失。在这 4 例中，使用 5 个标志物评估 MSI。所有肿瘤均具有高 MSI（MSI-H）状态。反式激活反应性 RNA 结合蛋白 2 是 DICER1 包含复合物的一个组成部分，是 DNA 错配修复缺陷的潜在靶标。具有 MSI 的胃肠道癌症中已鉴定出截断突变。以前的研究尚未评估 MSI UUT-UC 中该基因的突变状态。在这项研究中，我们通过逆转录聚合酶链反应分析了 MSI-H UUT-UC 中 TARBP2 的突变。在 MSI-H UUT-UC 中未发现截断突变。
