Extrachromosomal circular DNA (eccDNA), a chromosome-independent circular DNA, has garnered significant attention due to its widespread distribution and intricate biogenesis in carcinoma. Existing research findings propose that multiple eccDNAs contribute to drug resistance in cancer treatments through complex and interrelated regulatory mechanisms. The unique structure and genetic properties of eccDNA increase tumor heterogeneity. This increased diversity is a result of eccDNA's ability to stimulate oncogene remodeling and participate in anomalous splicing processes through chimeric cyclization and the reintegration of loop DNA back into the linear genome. Such actions promote oncogene amplification and silencing. eccDNA orchestrates protein interactions and modulates protein degradation by acting as a regulatory messenger. Moreover, it plays a pivotal role in modeling the tumor microenvironment and intensifying the stemness characteristics of tumor cells. This review presented detailed information about the biogenesis, distinguishing features, and functions of eccDNA, emphasized the role and mechanisms of eccDNA during cancer treatment, and further proposed the great potential of eccDNA in inspiring novel strategies for precision cancer therapy and facilitating the discovery of prognostic biomarkers for cancer.

染色体外环状DNA（eccDNA）是一种独立于染色体的环状DNA，由于其在癌症中的广泛分布和复杂的生物发生而引起了人们的广泛关注。现有的研究结果表明，多种 eccDNA 通过复杂且相互关联的调节机制导致癌症治疗中的耐药性。eccDNA 独特的结构和遗传特性增加了肿瘤的异质性。这种增加的多样性是由于 eccDNA 能够刺激癌基因重塑并通过嵌合环化和环 DNA 重新整合回线性基因组来参与异常剪接过程。这些行为促进癌基因扩增和沉默。eccDNA 通过充当调节信使来协调蛋白质相互作用并调节蛋白质降解。此外，它在模拟肿瘤微环境和增强肿瘤细胞的干性特征方面发挥着关键作用。该综述详细介绍了 eccDNA 的生物发生、显着特征和功能，强调了 eccDNA 在癌症治疗中的作用和机制，并进一步提出了 eccDNA 在激发癌症精准治疗新策略和促进预后发现方面的巨大潜力。癌症的生物标志物。