Activating Mutations in PTPN3 Promote Cholangiocarcinoma Cell Proliferation and Migration and Are Associated With Tumor Recurrence in Patients
Activating Mutations in PTPN3 Promote Cholangiocarcinoma Cell Proliferation and Migration and Are Associated With Tumor Recurrence in Patients
复制标题
PTPN3 的激活突变可促进胆管癌细胞增殖和迁移，并与患者的肿瘤复发相关。
DOI：
10.1053/j.gastro.2014.01.062
复制
发表时间：
2014-05-01
期刊：
影响因子：
29.4
通讯作者：
Fan, Jia
中科院分区：
文献类型：
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作者：
Gao, Qiang;Zhao, Ying-Jun;Fan, Jia
背景和目标
肝内胆管细胞癌(ICC)是第二大常见的肝癌，其发病机制目前尚不清楚，其发病率在全球范围内呈上升趋势。我们在人类ICC肿瘤样本中寻找突变，并研究它们如何影响ICC细胞功能。
方法
我们对7对ICC肿瘤及其周围非肿瘤组织进行了全外显子组测序，以检测体细胞的变化。然后，我们筛选了124对ICC和非肿瘤样本中的这些突变，包括7个外显子。我们比较了124名患者中PTPN3基因突变与肿瘤复发的关系，以及322名患者中PTPN3表达水平与肿瘤复发的关系(86名患者同时使用这两种方法)。通过RNA干扰和在胆管癌细胞系(RBE、HCCC-9810和Huh28)中的转基因表达来确定PTPN3变异的功能效应。
结果
根据外显子组测序，在ICC样本中，调节蛋白质磷酸化的途径是最常见的改变之一，编码蛋白酪氨酸磷酸酶(PTPs)的基因是最频繁突变的基因之一。我们在7个ICC外显子中的4个发现了9个编码PTPs的基因突变。在124对配对样本的患病率筛查中，51.6%的ICC在9个PTP基因中至少有1个存在体细胞突变；41.1%的ICC存在PTPN3突变。PTPN3在细胞系中的转基因表达增加了细胞的增殖、集落形成和迁移。在ICC样本中经常检测到的PTPN3(L232R)和PTPN3(L384H)被发现是功能获得突变；它们在细胞系中的表达进一步促进了细胞的增殖、克隆形成和迁移。与ICC相关的PTPN3变异体改变了磷酸酶活性。肿瘤含有激活突变或PTPN3蛋白水平高于非肿瘤组织的患者比不具有这些特征的肿瘤患者的疾病复发率更高。
结论
使用患者ICC样本的整个外显子组测序，我们发现超过40%的人含有PTPN3的体细胞突变。PTPN3的激活突变和高表达水平与肿瘤复发有关。
BACKGROUND & AIMS
The pathogenesis of intrahepatic cholangiocarcinoma (ICC), the second most common hepatic cancer, is poorly understood, and the incidence of ICC is increasing worldwide. We searched for mutations in human ICC tumor samples and investigated how they affect ICC cell function.
METHODS
We performed whole exome sequencing of 7 pairs of ICC tumors and their surrounding nontumor tissues to detect somatic alterations. We then screened 124 pairs of ICC and nontumor samples for these mutations, including 7 exomes. We compared mutations in PTPN3 with tumor recurrence in 124 patients and PTPN3 expression levels with recurrence in 322 patients (the combination of both in 86 patients). The functional effects of PTPN3 variations were determined by RNA interference and transgenic expression in cholangiocarcinoma cell lines (RBE, HCCC-9810, and Huh28).
RESULTS
Based on exome sequencing, pathways that regulate protein phosphorylation were among the most frequently altered in ICC samples and genes encoding protein tyrosine phosphatases (PTPs) were among the most frequently mutated. We identified mutations in 9 genes encoding PTPs in 4 of 7 ICC exomes. In the prevalence screen of 124 paired samples, 51.6% of ICCs contained somatic mutations in at least 1 of 9 PTP genes; 41.1% had mutations in PTPN3. Transgenic expression of PTPN3 in cell lines increased cell proliferation, colony formation, and migration. PTPN3(L232R) and PTPN3(L384H), which were frequently detected in ICC samples, were found to be gain-of-function mutations; their expression in cell lines further increased cell proliferation, colony formation, and migration. ICC-associated variants of PTPN3 altered phosphatase activity. Patients whose tumors contained activating mutations or higher levels of PTPN3 protein than nontumor tissues had higher rates of disease recurrence than patients whose tumors did not have these characteristics.
CONCLUSIONS
Using whole exome sequencing of ICC samples from patients, we found that more than 40% contain somatic mutations in PTPN3. Activating mutations in and high expression levels of PTPN3 were associated with tumor recurrence.