尽管去泛素酶（DUB）在肝脏肿瘤发生中已经得到了很好的描述，但它们的潜在作用和机制尚未完全了解。在这项研究中，我们确定泛素特异性蛋白酶 1 (USP1) 是一种癌基因，在肝细胞癌 (HCC) 进展过程中发挥重要作用。 USP1 具有升高的表达水平和临床意义，在多个生物信息学数据集中被确定为 HCC 的中心 DUB。从功能上讲，USP1过表达显着增强了体外肝癌细胞系和球体以及体内斑马鱼模型和异种移植模型的恶性行为。相比之下，USP1 的基因消除或药理学抑制会显着损害 HCC 细胞的表型。具体来说，异位USP1通过调节线粒体动力学增强HCC细胞的侵袭性和代谢重编程。从机制上讲，USP1 通过去泛素化和细胞周期蛋白依赖性激酶 5 (CDK5) 的稳定（可被 E3 连接酶 NEDD4L 降解）来增强 Drp1 Ser616 的磷酸化，从而诱导线粒体裂变。 USP1/CDK5调节轴在HCC组织中被激活，这与HCC患者的不良预后相关。此外，通过广泛的计算研究与实验验证相结合，普拉格雷被确定为针对 HCC 表型的候选 USP1 抑制剂。总而言之，USP1 通过以 CDK5 介导的 Drp1 磷酸化方式调节线粒体动力学来诱导恶性表型和代谢重编程，从而恶化 HCC 进展。© 2024。作者获得 ADMC Associazione Differenziamento e Morte Cellulare 的独家许可。

Although deubiquitinases (DUBs) have been well described in liver tumorigenesis, their potential roles and mechanisms have not been fully understood. In this study, we identified ubiquitin-specific protease 1 (USP1) as an oncogene with essential roles during hepatocellular carcinoma (HCC) progression. USP1, with elevated expression levels and clinical significance, was identified as a hub DUB for HCC in multiple bioinformatics datasets. Functionally, USP1 overexpression significantly enhanced the malignant behaviors in HCC cell lines and spheroids in vitro, as well as the zebrafish model and the xenograft model in vivo. In contrast, genetic ablation or pharmacological inhibition of USP1 dramatically impaired the phenotypes of HCC cells. Specifically, ectopic USP1 enhanced aggressive properties and metabolic reprogramming of HCC cells by modulating mitochondrial dynamics. Mechanistically, USP1 induced mitochondrial fission by enhancing phosphorylation of Drp1 at Ser616 via deubiquitination and stabilization of cyclin-dependent kinase 5 (CDK5), which could be degraded by the E3 ligase NEDD4L. The USP1/CDK5 modulatory axis was activated in HCC tissues, which was correlated with poor prognosis of HCC patients. Furthermore, Prasugrel was identified as a candidate USP1 inhibitor for targeting the phenotypes of HCC by an extensive computational study combined with experimental validations. Taken together, USP1 induced malignant phenotypes and metabolic reprogramming by modulating mitochondrial dynamics in a CDK5-mediated Drp1 phosphorylation manner, thereby deteriorating HCC progression.© 2024. The Author(s), under exclusive licence to ADMC Associazione Differenziamento e Morte Cellulare.