Institute for Infection Prevention and Hospital Epidemiology; Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany.
German Cancer Consortium (DKTK), Partner Site Freiburg and German Cancer Research Center (DKFZ), Heidelberg, Germany.
Nanomedicine. 2018 Apr;14(3):875-882. doi: 10.1016/j.nano.2017.12.009. Epub 2017 Dec 27.
Clinical evidence in oncology argues for the advantages of performing molecular analysis of blood biomarkers to provide information about systemic changes and tumor heterogeneity. Whereas the diagnostic value of cell-free circulating DNA (fcDNA) has successfully been demonstrated in several studies, DNA enclosed in extracellular vesicles (EV) has only recently been described, and its potential diagnostic value is unclear. We established a protocol for separation of EV and fc fractions and tested for presence of mutant BRAFV600E mediating resistance to Vemurafenib and cKITD816V mediating resistance to Imatinib in blood of patients with melanoma and mastocytosis. Our results show that EV contain significantly higher amounts of total DNA as compared to the fc fraction. However, about ten-fold higher copy numbers of the wild type and mutant BRAF and cKIT were detected in the fcDNA fraction supporting its diagnostic value and pointing to differences in fc and EV DNA content.
肿瘤学的临床证据表明，进行血液生物标志物的分子分析具有提供有关全身变化和肿瘤异质性信息的优势。虽然游离循环 DNA（fcDNA）的诊断价值已在多项研究中得到成功证实，但最近才描述了包含在细胞外囊泡（EV）中的 DNA，其潜在的诊断价值尚不清楚。我们建立了一种分离 EV 和 fc 部分的方案，并检测了黑色素瘤和肥大细胞增多症患者血液中导致vemurafenib 耐药的 BRAFV600E 突变体和导致 imatinib 耐药的 cKITD816V 的存在。我们的结果表明，与 fc 部分相比，EV 中总 DNA 的含量明显更高。然而，在 fcDNA 部分中检测到野生型和突变型 BRAF 和 cKIT 的拷贝数高十倍左右，这支持了其诊断价值，并指出了 fc 和 EV DNA 含量的差异。
