A mosaic activating mutation in AKT1 associated with the Proteus syndrome.
A mosaic activating mutation in AKT1 associated with the Proteus syndrome.
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DOI：
10.1056/nejmoa1104017
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发表时间：
2011-08-18
期刊：
影响因子：
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通讯作者：
Biesecker LG
中科院分区：
文献类型：
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作者：
Lindhurst MJ;Sapp JC;Teer JK;Johnston JJ;Finn EM;Peters K;Turner J;Cannons JL;Bick D;Blakemore L;Blumhorst C;Brockmann K;Calder P;Cherman N;Deardorff MA;Everman DB;Golas G;Greenstein RM;Kato BM;Keppler-Noreuil KM;Kuznetsov SA;Miyamoto RT;Newman K;Ng D;O'Brien K;Rothenberg S;Schwartzentruber DJ;Singhal V;Tirabosco R;Upton J;Wientroub S;Zackai EH;Hoag K;Whitewood-Neal T;Robey PG;Schwartzberg PL;Darling TN;Tosi LL;Mullikin JC;Biesecker LG
变形综合征的特征是皮肤、结缔组织、脑和其他组织的过度生长。据推测，该综合征是由体细胞嵌合体引起的突变，在非嵌合状态下是致命的。我们对从变形综合征患者获得的活检样品进行了DNA外显子组测序，并将所得DNA序列与从相同患者获得的未受影响的组织的DNA序列进行了比较。我们使用自定义限制性内切酶分析法分析了29例变形综合征患者的158份样本的DNA，证实并扩展了观察到的相关性。然后，我们用磷酸化特异性抗体对蛋白质印迹法检测了受影响组织中AKT蛋白的活化。在29例变形综合征患者中，26例在编码AKT 1激酶的癌基因AKT 1中存在体细胞激活突变（c.49G→A，p.Glu17Lys），AKT 1激酶是一种已知介导细胞增殖和凋亡等过程的酶。变形综合征患者的组织和细胞系中含有1%至约50%的突变等位基因混合物。突变细胞系显示出更大的AKT磷酸化比对照细胞系。从相同的起始培养物建立的一对单细胞克隆，其突变状态不同，具有不同的AKT磷酸化水平。Proteus综合征是由AKT 1的体细胞激活突变引起的，证明了体细胞嵌合体的假设，并在这种疾病的过度生长和肿瘤易感性的特征性临床发现中涉及PI 3 K-AKT通路的激活。（由国家人类基因组研究所校内研究计划资助。
The Proteus syndrome is characterized by the overgrowth of skin, connective tissue, brain, and other tissues. It has been hypothesized that the syndrome is caused by somatic mosaicism for a mutation that is lethal in the nonmosaic state. We performed exome sequencing of DNA from biopsy samples obtained from patients with the Proteus syndrome and compared the resultant DNA sequences with those of unaffected tissues obtained from the same patients. We confirmed and extended an observed association, using a custom restriction-enzyme assay to analyze the DNA in 158 samples from 29 patients with the Proteus syndrome. We then assayed activation of the AKT protein in affected tissues, using phosphorylation-specific antibodies on Western blots. Of 29 patients with the Proteus syndrome, 26 had a somatic activating mutation (c.49G→A, p.Glu17Lys) in the oncogene AKT1, encoding the AKT1 kinase, an enzyme known to mediate processes such as cell proliferation and apoptosis. Tissues and cell lines from patients with the Proteus syndrome harbored admixtures of mutant alleles that ranged from 1% to approximately 50%. Mutant cell lines showed greater AKT phosphorylation than did control cell lines. A pair of single-cell clones that were established from the same starting culture and differed with respect to their mutation status had different levels of AKT phosphorylation. The Proteus syndrome is caused by a somatic activating mutation in AKT1, proving the hypothesis of somatic mosaicism and implicating activation of the PI3K–AKT pathway in the characteristic clinical findings of overgrowth and tumor susceptibility in this disorder. (Funded by the Intramural Research Program of the National Human Genome Research Institute.)