Polyclonality of BRAF Mutations in Acquired Melanocytic Nevi
Polyclonality of BRAF Mutations in Acquired Melanocytic Nevi
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DOI：
10.1093/jnci/djp309
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发表时间：
2009-10-21
影响因子：
10.3
通讯作者：
Saida, Toshiaki
中科院分区：
文献类型：
--
作者：
Lin, Jingrong;Takata, Minoru;Saida, Toshiaki
黑色素细胞痣被认为是黑素细胞的衰老克隆，获得了致癌的BRAF突变。BRAF突变被认为是启动黑素细胞转化的关键步骤。然而，使用免疫磁分离或激光捕获显微切割，我们检测了从13名患者的获得性黑色素细胞痣分离的大约50个单细胞中的BRAF突变，发现大量含有野生型BRAF的痣细胞与含有BRAF(V600E)的痣细胞混合。此外，我们同时扩增了BRAF外显子15和邻近的单核苷酸多态(SNP)rs7801086，该SNP来自4名杂合子的患者。聚合酶链式反应产物的亚克隆和测序表明，两个SNP等位基因都含有BRAF(V600E)突变，表明相同的BRAF(V600E)突变来自不同的细胞。获得性黑素细胞痣中BRAF突变的多克隆性提示BRAF突变可能不是黑素细胞转化的初始事件。
Melanocytic nevi are thought to be senescent clones of melanocytes that have acquired an oncogenic BRAF mutation. BRAF mutation is considered to be a crucial step in the initiation of melanocyte transformation. However, using immunomagnetic separation or laser-capture microdissection, we examined BRAF mutations in sets of approximately 50 single cells isolated from acquired melanocytic nevi from 13 patients and found a substantial number of nevus cells that contained wild-type BRAF mixed with nevus cells that contained BRAF(V600E). Furthermore, we simultaneously amplified BRAF exon 15 and a neighboring single nucleotide polymorphism (SNP), rs7801086, from nevus cell samples obtained from four patients who were heterozygous for this SNP. Subcloning and sequencing of the polymerase chain reaction products showed that both SNP alleles harbored the BRAF(V600E) mutation, indicating that the same BRAF(V600E) mutation originated from different cells. The polyclonality of BRAF mutations in acquired melanocytic nevi suggests that mutation of BRAF may not be an initial event in melanocyte transformation.