虽然N4-乙酰胞苷（ac4C）修饰影响mRNA的稳定性和翻译，但其是否存在于非编码RNA中未知，其生物功能也不清楚。这里，通过核苷酸分辨率方法，对CTC-490G23.2 ac4C位点进行了分析，并进行了增益和失活实验，发现乙酰转移酶10（NAT10）负责长链非编码RNA（lncRNA）的ac4C修饰。 NAT10介导的ac4C修饰导致主食管鳞癌（ESCC）中lncRNA CTC-490G23.2的稳定性和过度表达，并在转移组织中进一步上调。 CTC-490G23.2在体外和体内显着促进了癌症侵入和转移。在机械方面，CTC-490G23.2作为一个支架，增加了CD44前mRNA与多聚嘧啶轨道结合蛋白1（PTBP1）的结合，并导致从标准型CD44s向变异型CD44v（8-10）的肿瘤剪切开关。 CD44v（8-10）而不是CD44s结合并增加vimentin的蛋白稳定性。CTC-490G23.2和CD44v（8-10）的表达水平可以预测癌症患者的预后不良。此外，针对CTC490G23.2的反义寡核苷酸（ASO）/ SV40-LAH4-L1肽自组装纳米复合物对癌症转移具有显着的抑制作用。本研究的结果将为lncRNA的ac4C修饰提供新的机制洞见，为新型系统治疗和预后生物标志物的开发提供有用线索。 © 2023.该作者（或者作者团体）独家授权给施普林格自然有限公司。

Although N4-acetylcytidine (ac4C) modification affects the stability and translation of mRNA, it is unknown whether it exists in noncoding RNAs, and its biological function is unclear. Here, nucleotide-resolution method for profiling CTC-490G23.2 ac4C sites and gain- and loss-of-function experiments revealed that N-acetyltransferase 10 (NAT10) is responsible for ac4C modification of long noncoding RNAs (lncRNAs). NAT10-mediated ac4C modification leads to the stabilization and overexpression of lncRNA CTC-490G23.2 in primary esophageal squamous cell carcinoma (ESCC) and its further upregulation in metastatic tissues. CTC-490G23.2 significantly promotes cancer invasion and metastasis in vitro and in vivo. Mechanistically, CTC-490G23.2 acts as a scaffold to increase the binding of CD44 pre-mRNA to polypyrimidine tract-binding protein 1 (PTBP1), resulting in a oncogenic splicing switch from the standard isoform CD44s to the variant isoform CD44v(8-10). CD44v(8-10), but not CD44s, binds to and increases the protein stability of vimentin. Expression levels of CTC-490G23.2 and CD44v(8-10) can predict poor prognosis in cancer patients. Furthermore, the antisense oligonucleotide (ASO)/SV40-LAH4-L1 peptide self-assembled nanocomplexes targeting CTC490G23.2 exerts a significantly suppressive effect on cancer metastasis. The outcome of this study will provide new mechanistic insight into the ac4C modification of lncRNAs and useful clues for the development of novel systemic therapies and prognostic biomarkers.© 2023. The Author(s), under exclusive licence to Springer Nature Limited.