Chen Christopher, Addepalli Kush, Soldan Samantha S, Castro-Munoz Leonardo Josue, Preston-Alp Sarah, Patel Rishi J, Albitz Coltin J, Tang Hsin-Yao, Tempera Italo, Lieberman Paul M
The Wistar Institute, Philadelphia, Pennsylvania, USA.
University of Pennsylvania, Philadelphia, Pennsylvania, USA.
J Med Virol. 2025 Jan;97(1):e70168. doi: 10.1002/jmv.70168.
Epstein-Barr virus (EBV) is a ubiquitous human ɣ-herpesvirus implicated in various malignancies, including Burkitt's lymphoma and gastric carcinomas. In most EBV-associated cancers, the viral genome is maintained as an extrachromosomal episome by the EBV nuclear antigen-1 (EBNA1). EBNA1 is considered to be a highly stable protein that interacts with the ubiquitin-specific protease 7 (USP7). Here, we show that pharmacological inhibitors and small interfering RNA (siRNA) targeting USP7 reduce EBNA1 protein levels in a proteosome-dependent manner. Proteomic analysis revealed that USP7 inhibitor GNE6776 altered the EBNA1 protein interactome, including disrupting USP7 association with EBNA1. GNE6776 also inhibited EBNA1 binding to EBV oriP DNA and reduced viral episome copy number. Transcriptomic studies revealed that USP7 inhibition affected chromosome segregation and mitotic cell division pathways in EBV cells. Finally, we show that GNE6776 selectively inhibited EBV gastric and lymphoid cell proliferation in cell culture and slowed EBV tumor growth in mouse xenograft models. These findings suggest that USP7 inhibitors perturb EBNA1 stability and function and may be exploited to treat EBV latent infection and tumorigenesis.
爱泼斯坦-巴尔病毒（EBV）是一种普遍存在的人类γ-疱疹病毒，与包括伯基特淋巴瘤和胃癌在内的多种恶性肿瘤有关。在大多数与EBV相关的癌症中，病毒基因组通过EBV核抗原1（EBNA1）维持为染色体外附加体。EBNA1被认为是一种高度稳定的蛋白质，可与泛素特异性蛋白酶7（USP7）相互作用。在这里，我们表明，靶向USP7的药理抑制剂和小干扰RNA（siRNA）以蛋白酶体依赖性方式降低EBNA1蛋白水平。蛋白质组学分析显示，USP7抑制剂GNE6776改变了EBNA1蛋白相互作用组，包括破坏USP7与EBNA1的结合。GNE6776还抑制EBNA1与EBV oriP DNA的结合并降低病毒附加体拷贝数。转录组学研究表明，USP7抑制影响EBV细胞中的染色体分离和有丝分裂细胞分裂途径。最后，我们表明GNE6776在细胞培养中选择性抑制EBV胃和淋巴细胞增殖，并减缓小鼠异种移植模型中EBV肿瘤的生长。这些发现表明，USP7抑制剂会干扰EBNA1的稳定性和功能，可能被用于治疗EBV潜伏感染和肿瘤发生。
