The tumour microenvironment (TME) constitutes the area surrounding the tumour during its development and has been demonstrated to play roles in cancer-related diseases through crosstalk with tumour cells. Circular RNAs (circRNAs) are a subpopulation of endogenous noncoding RNAs (ncRNAs) that are ubiquitously expressed in eukaryotes and have multiple biological functions in the regulation of cancer onset and progression. An increasing number of studies have shown that circRNAs participate in the multifaceted biological regulation of the TME. However, details on the mechanisms involved have remained elusive until now. In this review, we analyse the effects of circRNAs on the TME from various perspectives, including immune surveillance, angiogenesis, hypoxia, matrix remodelling, exo-circRNAs and chemoradiation resistance. Currently, the enormous potential for circRNA use in targeted therapy and as noninvasive biomarkers have drawn our attention. We emphasize the prospect of targeting circRNAs as an essential strategy to regulate TME, overcome cancer resistance and improve therapeutic outcomes.

中文翻译：

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circRNA在肿瘤微环境中的作用。

肿瘤微环境（TME）构成了肿瘤发展过程中的周围区域，并已通过与肿瘤细胞的串扰证明在肿瘤相关疾病中发挥作用。环状RNA（circRNA）是内源非编码RNA（ncRNA）的一个亚群，在真核生物中普遍表达，并在调控癌症的发生和发展中具有多种生物学功能。越来越多的研究表明，circRNA参与了TME的多方面生物学调控。但是，有关机制的细节至今仍难以捉摸。在这篇综述中，我们从各种角度分析了circRNAs对TME的影响，包括免疫监视，血管生成，缺氧，基质重塑，exo-circRNAs和化学辐射抗性。目前，circRNA在靶向治疗中的巨大潜力以及作为非侵入性生物标志物已引起我们的关注。我们强调靶向circRNA作为调节TME，克服癌症耐药性和改善治疗效果的基本策略的前景。