CircRNAs are crucial in tumorigenesis and metastasis, and are comprehensively downregulated in hepatocellular carcinoma (HCC). Previous studies demonstrated that the back-splicing of circRNAs was closely related to 3′-end splicing. As a core executor of 3′-end cleavage, we hypothesized that CPSF3 modulated circRNA circularization. Clinical data were analyzed to establish the prognostic correlations. Cytological experiments were performed to determine the role of CPSF3 in HCC. A fluorescent reporter was employed to explore the back-splicing mechanism. The circRNAs regulated by CPSF3 were screened by RNA-seq and validated by PCR, and changes in downstream pathways were explored by molecular experiments. Finally, the safety and efficacy of the CPSF3 inhibitor JTE-607 were verified both in vitro and in vivo. The results showed that CPSF3 was highly expressed in HCC cells, promoting their proliferation and migration, and that a high CPSF3 level was predictive of a poor prognosis. A mechanistic study revealed that CPSF3 enhanced RNA cleavage, thereby reducing circRNAs, and increasing linear mRNAs. Furthermore, inhibition of CPSF3 by JET-607 suppressed the proliferation of HCC cells. Our findings indicate that the increase of CPSF3 in HCC promotes the shift of pre-mRNA from circRNA to linear mRNA, leading to uncontrolled cell proliferation. JTE-607 exerted a therapeutic effect on HCC by blocking CPSF3.
环状RNA在肿瘤发生和转移中起关键作用，且在肝细胞癌中普遍下调。先前研究表明，环状RNA的反向剪接与3′末端剪接密切相关。作为3′末端切割的核心执行因子，我们推测CPSF3可能调控环状RNA的环化过程。通过分析临床数据，我们建立了其与预后的相关性。细胞实验用于验证CPSF3在肝细胞癌中的作用机制。利用荧光报告系统探索反向剪接机制，通过RNA测序筛选CPSF3调控的环状RNA并经PCR验证，同时采用分子实验探究下游通路变化。最后，在体外和体内实验中验证了CPSF3抑制剂JTE-607的安全性和疗效。结果显示，CPSF3在肝细胞癌细胞中高表达，能促进细胞增殖和迁移，且高表达水平提示不良预后。机制研究表明，CPSF3通过增强RNA切割减少环状RNA生成，同时增加线性mRNA。此外，JTE-607对CPSF3的抑制能有效抑制肝细胞癌细胞增殖。本研究揭示肝细胞癌中CPSF3的升高可促使前体RNA从环状RNA向线性mRNA转化，导致细胞增殖失控，而JTE-607通过阻断CPSF3发挥治疗作用。
CPSF3 Promotes Pre-mRNA Splicing and Prevents CircRNA Cyclization in Hepatocellular Carcinoma
肿瘤(癌症)患者之家