BACKGROUND AND AIMS Base editing has shown great potential for treating human diseases with mutated genes. However, its potential for treating hepatocarcinoma (HCC) has not yet explored. APPROACH AND RESULTS We employed adenine base editors (ABEs) to correct a TERT promoter mutation, which frequently occurs in various human cancers, including HCC. The mutated TERT promoter -124 C>T is corrected to -124 C by a single guide (sg) RNA-guided and deactivated Campylobacter jejuni Cas9 (CjCas9)-fused adenine base editor (CjABE). This edit impairs the binding of the ETS (ETS/TCF) transcription factor family, including ETS1 and GABPA, to the TERT promoter, leading to suppressed TERT promoter and telomerase activity, decreased TERT expression and cell proliferation, and increased cell senescence. Importantly, injection of adeno-associated viruses expressing sgRNA-guided CjABE or employment of lipid nanoparticle-mediated delivery of CjABE mRNA and sgRNA inhibits the growth of liver tumors harboring TERT promoter mutations. CONCLUSIONS These findings demonstrate that a sgRNA-guided CjABE efficiently converts the mutated TERT promoter -124 C>T to -124 C in HCC cells and underscore the potential to treat HCC by the base editing-mediated correction of TERT promoter mutations.

中文翻译：

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突变的 TERT 启动子的碱基编辑可抑制肝肿瘤的生长。

背景和目的 碱基编辑已显示出治疗突变基因人类疾病的巨大潜力。然而，其治疗肝癌（HCC）的潜力尚未被探索。方法和结果我们采用腺嘌呤碱基编辑器 (ABE) 来纠正 TERT 启动子突变，这种突变经常发生在各种人类癌症中，包括 HCC。突变的 TERT 启动子 -124 C>T 通过单向导 (sg) RNA 引导且失活的空肠弯曲菌 Cas9 (CjCas9) 融合腺嘌呤碱基编辑器 (CjABE) 校正为 -124 C。这种编辑会损害 ETS (ETS/TCF) 转录因子家族（包括 ETS1 和 GABPA）与 TERT 启动子的结合，导致 TERT 启动子和端粒酶活性受到抑制，TERT 表达和细胞增殖减少，并增加细胞衰老。重要的是，注射表达 sgRNA 引导的 CjABE 的腺相关病毒或使用脂质纳米颗粒介导的 CjABE mRNA 和 sgRNA 递送可抑制含有 TERT 启动子突变的肝肿瘤的生长。结论 这些发现表明，sgRNA 引导的 CjABE 在 HCC 细胞中有效地将突变的 TERT 启动子 -124 C>T 转化为 -124 C，并强调了通过碱基编辑介导的 TERT 启动子突变校正来治疗 HCC 的潜力。