Exosomes, a special type of membrane-bound extracellular vesicle regarded as an ideal carrier for intercellular messages, play an essential role in intercellular communication both locally and systematically. Recent studies have reported that circular RNAs (circRNAs), members of the noncoding RNA family, are abundant and stable in exosomes. As an essential mediator of intercellular communication within cancer cells or between cancer cells and noncancerous cells, exosomal circRNAs participate in multiple aspects of cancer. In this review, we summarize the biogenesis, properties and functions of exosomal circRNAs. In particular, we describe their intercellular transfer in the tumour microenvironment and associate their biological functions with different phenotypes of cancer. Finally, we discuss potential clinical applications in the future.

中文翻译：

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外泌体环状 RNA 的新见解：重新定义癌症生物学中的细胞间通讯

外泌体是一种特殊类型的膜结合细胞外囊泡，被认为是细胞间信息的理想载体，在局部和系统的细胞间通讯中发挥着重要作用。最近的研究报道，非编码 RNA 家族的成员环状 RNA (circRNA) 在外泌体中含量丰富且稳定。作为癌细胞内或癌细胞与非癌细胞之间细胞间通讯的重要介质，外泌体环状RNA参与癌症的多个方面。在这篇综述中，我们总结了外泌体 circRNA 的生物发生、特性和功能。特别是，我们描述了它们在肿瘤微环境中的细胞间转移，并将它们的生物学功能与癌症的不同表型联系起来。最后，我们讨论了未来潜在的临床应用。