Gain-of-function mutations in DNMT3A in patients with paraganglioma
Gain-of-function mutations in DNMT3A in patients with paraganglioma
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DOI：
10.1038/s41436-018-0003-y
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发表时间：
2018-12-01
影响因子：
8.8
通讯作者：
Cascon, Alberto
中科院分区：
文献类型：
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作者：
Remacha, Laura;Curras-Freixes, Maria;Cascon, Alberto
目的：嗜铬细胞瘤/副神经节瘤携带生殖系突变的患者比例很高，这使得嗜铬细胞瘤/副神经节瘤成为所有肿瘤中最具遗传性的。然而，仍有一些病例无法用已知基因的突变来解释。我们的目的是确定强烈怀疑有遗传性tumors.Methods的患者的遗传病因：全外显子组测序应用于生殖系的父母先证者三人。全基因组甲基化组分析、RNA-seq、CRISPR/Cas9基因编辑和靶向测序也进行了。结果：我们在DNMT 3A中鉴定了一种新的从头生殖系突变，影响了一个高度保守的残基，该残基位于与三甲基化组蛋白H3结合的芳香笼附近。DNMT 3A突变的肿瘤表现出显着的含同源框基因的高甲基化，表明突变的激活作用。HeLa细胞中CRISPR/Cas9介导的基因敲入导致甲基化的整体变化，为DNMT 3A改变功能提供了证据。靶向测序显示另外6个副神经节瘤的亚克隆体细胞突变。最后，第二个生殖系DNMT 3A突变，也导致全球肿瘤DNA超甲基化，被发现在一个病人的家族史pheochromocytoma.Conclusion：我们的研究结果表明，DNMT 3A可能是一个易感基因副神经节瘤，如果在未来的研究中得到证实，将代表第一个例子的功能获得性突变影响的DNA甲基转移酶基因参与癌症易感性。
Purpose: The high percentage of patients carrying germline mutations makes pheochromocytomas/paragangliomas the most heritable of all tumors. However, there are still cases unexplained by mutations in the known genes. We aimed to identify the genetic cause of disease in patients strongly suspected of having hereditary tumors.Methods: Whole-exome sequencing was applied to the germlines of a parent-proband trio. Genome-wide methylome analysis, RNA-seq, CRISPR/Cas9 gene editing, and targeted sequencing were also performed.Results: We identified a novel de novo germline mutation in DNMT3A, affecting a highly conserved residue located close to the aromatic cage that binds to trimethylated histone H3. DNMT3A-mutated tumors exhibited significant hypermethylation of homeobox-containing genes, suggesting an activating role of the mutation. CRISPR/Cas9-mediated knock-in in HeLa cells led to global changes in methylation, providing evidence of the DNMT3A-altered function. Targeted sequencing revealed subclonal somatic mutations in six additional paragangliomas. Finally, a second germline DNMT3A mutation, also causing global tumor DNA hypermethylation, was found in a patient with a family history of pheochromocytoma.Conclusion: Our findings suggest that DNMT3A may be a susceptibility gene for paragangliomas and, if confirmed in future studies, would represent the first example of gain-of-function mutations affecting a DNA methyltransferase gene involved in cancer predisposition.