Extrachromosomal DNA (ecDNA) is a small segment of circular DNA located outside the chromosome, which has the function of self-replication. Recently, amplification of oncogenes on ecDNA has been proved to be a common phenomenon in tumor cells, and has some characteristics worth studying, such as correlation with patients' poor prognosis. Multiple chromosomal events are involved in the formation of ecDNA, and its amplification can directly increase the number of DNA copies of extra-chromosomal oncogenes and accelerate the generation and development of tumors. Moreover, the segregation pattern of unequal transmission of parental ecDNA cells to offspring not only increases tumor heterogeneity, but also enhances tumor adaptation to environment and response to therapy. This article reviews the current status and potential significance of ecDNA in tumor cells. .
【中文题目：染色体外癌基因扩增特点与肿瘤发生发展】 【中文摘要：染色体外DNA（extrachromosomal DNA, ecDNA）是位于染色体外的小片段环状DNA，具有自我复制功能。已有研究证明癌基因在ecDNA上被扩增是肿瘤细胞中的常见现象，并且具有一些值得研究的特征，如与患者的不良预后相关。多种染色体事件参与ecDNA形成，且它的扩增能直接使染色体外癌基因DNA拷贝数增加，加速肿瘤产生和发展。并且，亲代ecDNA细胞不均等传递到子代的分离方式，不仅增加肿瘤异质性，同时增强肿瘤对环境的适应和对治疗的反应能力。本文对ecDNA在肿瘤细胞中的研究现状及其潜在意义作一综述。 】 【中文关键词：染色体外DNA；双微体；染色体外环状DNA；肿瘤】.
Keywords: Double minutes; Extrachromosomal DNA; Extrachromosomal circular DNA; Tumor.