Xiangya School of Pharmaceutical Sciences in Central South University, Changsha, Hunan 410013, China.
Nucleic Acids Res. 2024 Sep 23;52(17):e83. doi: 10.1093/nar/gkae693.
CircRNA, an essential RNA molecule involved in various biological functions and diseases, often exhibits decreased expression in tumor tissues, playing a role as a tumor suppressor, and suggesting therapeutic potential for cancer. However, current methods for promoting circRNA production are limited. This study introduces a novel approach for enhancing circRNA biogenesis, termed circRNA promoting RNA (cpRNA). CpRNA is designed to complement the flanking sequences of reverse complementary matches (RCMs) within pre-mRNA, thereby facilitating circRNA formation through improved exon circularization. Using a split-GFP reporter system, we demonstrated that cpRNA significantly enhance circGFP production. Optimization identified the best conditions for cpRNA to promote circRNA biogenesis, and these cpRNAs were then used to augment the production of endogenous circRNAs. These results indicate that cpRNAs can specifically increase the production of endogenous circRNAs with RCMs, such as circZKSCAN1 and circSMARCA5 in cancer cells, thereby inhibiting cell proliferation and migration by modulating circRNA-related pathways, showcasing the therapeutic potential of cpRNAs. Mechanistic studies have also shown that cpRNA promotes circRNA biogenesis, in part, by antagonizing the unwinding function of DHX9. Overall, these findings suggest that cpRNA represents a promising strategy for circRNA overexpression, offering a potential treatment for diseases marked by low circRNA levels.
环状 RNA（circRNA）是一种参与多种生物学功能和疾病的重要 RNA 分子，其在肿瘤组织中常表现出低表达，作为肿瘤抑制因子发挥作用，提示其在癌症治疗方面具有潜力。然而，目前促进 circRNA 产生的方法有限。本研究提出了一种增强 circRNA 生物发生的新方法，称为环状 RNA 促进 RNA（cpRNA）。cpRNA 旨在补充前体 mRNA 中反向互补匹配（RCM）侧翼序列，从而通过提高外显子环化来促进 circRNA 的形成。使用分裂 GFP 报告系统，我们证明 cpRNA 可显著增强 circGFP 的产生。通过优化确定了 cpRNA 促进 circRNA 生物发生的最佳条件，然后使用这些 cpRNA 来增加内源性 circRNA 的产生。这些结果表明，cpRNA 可以特异性地增加具有 RCM 的内源性 circRNA 的产生，例如癌细胞中的 circZKSCAN1 和 circSMARCA5，从而通过调节 circRNA 相关途径抑制细胞增殖和迁移，展示了 cpRNA 的治疗潜力。机制研究还表明，cpRNA 通过拮抗 DHX9 的解旋功能促进 circRNA 生物发生。总之，这些发现表明 cpRNA 是一种有前途的 circRNA 过表达策略，为低 circRNA 水平标记的疾病提供了一种潜在的治疗方法。
