Acute myeloid leukemia (AML) is a heterogeneous malignant disease characterized by a collection of genetic and epigenetic changes. As a consequence, AML can evolve towards more aggressive subtypes during treatment, which require additional therapies to prevent future relapse. As we have previously detected double-stranded DNA (dsDNA) in tumor-derived extracellular vesicles (EVs), in this current study we attempted to evaluate the potential diagnostic applications of AML EV-dsDNA derived from primary bone marrow and peripheral blood plasma samples. EVs from plasma of 29 pediatric AML patients (at initial diagnosis or during treatment) were isolated by ultracentrifugation, after which dsDNA was extracted from obtained EVs and analyzed for leukemia-specific mutations using next generation sequencing (NGS) and GeneScan-based fragment-length analysis. In 18 out of 20 patients, dsDNA harvested from EVs mirrored the (leukemia-specific) mutations found in the genomic DNA obtained from primary leukemia cells. In the nanoparticle tracking analysis (NTA), a decrease in EV numbers was observed in patients after treatment compared with initial diagnosis. Following treatment, in 75 samples out of the 79, these mutations were no longer detectable in EV-dsDNA. In light of our results, we propose the use of leukemia-derived EV-dsDNA as an additional measure for mutational status and, potentially, treatment response in pediatric AML.

中文翻译：

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在儿童AML诊断中评估来自细胞外小泡（EVs）的dsDNA。

急性髓细胞性白血病（AML）是一种异质性恶性疾病，其特征是遗传和表观遗传学变化的集合。结果，在治疗过程中，AML可能演变为更具攻击性的亚型，这需要额外的治疗方法以防止将来复发。由于我们先前已在肿瘤来源的细胞外囊泡（EV）中检测到双链DNA（dsDNA），因此在本研究中，我们试图评估源自原代骨髓和外周血血浆样品的AML EV-dsDNA的潜在诊断应用。通过超速离心分离29例小儿AML患者血浆中的EV（在初始诊断或治疗期间），然后从获得的EV中提取dsDNA，并使用下一代测序（NGS）和基于GeneScan的片段长度分析白血病特异性突变分析。在20名患者中的18名患者中，从电动汽车中收集的dsDNA反映了从原发性白血病细胞获得的基因组DNA中发现的（白血病特异性）突变。在纳米颗粒追踪分析（NTA）中，与初始诊断相比，治疗后患者的EV值下降。处理后，在79个样本中的75个样本中，在EV-dsDNA中不再检测到这些突变。根据我们的结果，我们建议使用白血病来源的EV-dsDNA作为突变状态以及儿童AML潜在治疗反应的另一种测量方法。与初始诊断相比，治疗后患者的EV值下降。处理后，在79个样本中的75个样本中，在EV-dsDNA中不再检测到这些突变。根据我们的结果，我们建议使用白血病来源的EV-dsDNA作为突变状态以及儿童AML潜在治疗反应的另一种测量方法。与初始诊断相比，治疗后患者的EV值下降。处理后，在79个样本中的75个样本中，在EV-dsDNA中不再检测到这些突变。根据我们的结果，我们建议使用白血病来源的EV-dsDNA作为突变状态以及儿童AML潜在治疗反应的另一种测量方法。