Over the past decade, circular RNA (circRNA) research has evolved into a bona fide research field shedding light on the functional consequence of this unique family of RNA molecules in cancer. Although the method of formation and the abundance of circRNAs can differ from their cognate linear mRNA, the spectrum of interacting partners and their resultant cellular functions in oncogenesis are analogous. However, with 10 times more diversity in circRNA variants compared with linear RNA variants, combined with their hyperstability in the cell, circRNAs are equipped to influence every stage of oncogenesis. This is an opportune time to address the breadth of circRNA in cancer focused on their spatiotemporal expression, mutations in biogenesis factors and contemporary functions through each stage of cancer. In this Review, we highlight examples of functional circRNAs in specific cancers, which satisfy critical criteria, including their physical co-association with the target and circRNA abundance at stoichiometrically valid quantities. These considerations are essential to develop strategies for the therapeutic exploitation of circRNAs as biomarkers and targeted anticancer agents.

在过去的十年中，环状 RNA (circRNA) 研究已发展成为一个真正的研究领域，揭示了这一独特的 RNA 分子家族在癌症中的功能后果。尽管 circRNA 的形成方法和丰度可能与其同源线性 mRNA 不同，但相互作用伙伴的范围及其在肿瘤发生中产生的细胞功能是相似的。然而，与线性 RNA 变体相比，circRNA 变体的多样性高出 10 倍，再加上它们在细胞中的超稳定性，circRNA 能够影响肿瘤发生的每个阶段。现在是解决癌症中 circRNA 广泛性的好时机，重点关注其时空表达、生物发生因子的突变以及癌症各个阶段的当代功能。在这篇综述中，我们重点介绍了特定癌症中功能性 circRNA 的例子，这些例子满足关键标准，包括它们与靶标的物理共关联性以及化学计量有效量的 circRNA 丰度。这些考虑因素对于制定将 circRNA 作为生物标志物和靶向抗癌药物进行治疗利用的策略至关重要。