Targeting the ubiquitin-proteasome system has emerged as a powerful therapeutic strategy in oncology, particularly through modulation of deubiquitinating enzymes that regulate the stability of oncogenic proteins. Among these, ubiquitin-specific protease 7 (USP7) has garnered considerable attention due to its ability to deubiquitinate and stabilize multiple cancer-relevant substrates, including MDM2, FOXP3, N-Myc, and PTEN. By controlling protein turnover and subcellular localization of substrates, USP7 contributes to tumor progression across diverse types of cancer, positioning it as an attractive therapeutic target. Here, we report the identification of novel small-molecule USP7 inhibitors from a high-throughput screening campaign employing the fluorogenic ubiquitin-rhodamine enzymatic assay. Screening of 2446 compounds led to the identification of five hit compounds with measurable inhibitory activity against recombinant USP7 in vitro. These hits were further evaluated for antiproliferative activity across a panel of human and murine cancer cell lines with distinct molecular backgrounds. Among the identified hits, YM155 displayed the highest activity across all cancer types tested, exhibiting nanomolar IC₅₀ values in the proliferation assays. Importantly, YM155 demonstrated significant tumor growth inhibition in lung and breast cancer mouse models, supporting its in vivo activity and pharmacological tractability in clinically relevant settings. Together, these findings expand the chemical space of USP7 inhibitors and identify YM155 as a hit for further optimization and mechanistic investigation toward USP7-targeted anticancer therapeutics.

2026-08-01·EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY

Development and validation of a fluorescence polarization-based assay for USP7: From probe design to inhibitor evaluation

Article

作者: Luo, Cheng ; Tao, Yunsu ; Zhong, Hui ; Chen, Siji ; Liu, Yiling ; Xiong, Huan ; Wang, Mingchen ; Li, Xinyuan ; Zeng, Yasi ; Chen, Shijie ; Yang, Xu

Ubiquitin-specific protease 7 (USP7) is a key member of the deubiquitinating enzyme family. It is abnormally overexpressed in various malignancies, including breast cancer, chronic lymphocytic leukemia, and prostate cancer. By regulating pathways such as the p53-MDM2 signaling axis, USP7 promotes tumorigenesis and progression, making it a highly promising therapeutic target for anticancer treatment. Although multiple USP7 inhibitors have been reported, existing screening and evaluation assays exhibit limitations: the ubiquitin-phospholipase A₂ (Ub-PLA₂) assay frequently produces false-positive results, while the ubiquitin-rhodamine (Ub-Rho) assay is susceptible to interference from compound autofluorescence. To address this challenge, we developed a fluorescence polarization (FP) assay. This employs a rationally designed strategy that exhibits excellent characteristics, making it a simple-to-operate and cost-effective method, suitable for the evaluation of compound bioactivity against USP7. To further validate the practicality and reliability of this FP assay, we conducted a structure-based drug design campaign involving two rounds of systematic structural optimization, yielding 51 novel derivatives featuring pyrazolo[4,3-d]pyrimidine and piperidol scaffolds. Following FP evaluation and Ub-Rho enzyme activity validation, we performed a comprehensive structure-activity relationship (SAR) analysis. Ultimately, in vitro cellular assays identified three compounds (LC-U7-44, LC-U7-48, and LC-U7-50) that exhibit potent USP7 inhibitory activity alongside favorable cellular anti-proliferative effects. Overall, the established FP assay in this study closes a methodological gap in the evaluation of USP7 inhibitors, and the detailed SAR analysis provides a foundation for the further development of potent USP7 inhibitors.

2026-07-03·Nanomedicine

Targeting USP7 - a nano-therapeutic approach to restore and reactivate P53 for promoting apoptosis in glioma therapy

Article

作者: Kumar, Sunny ; Ghosh, Mrinal K.

BACKGROUND:

Glioblastoma remains one of the most lethal brain malignancies due to its profound molecular heterogeneity, invasive biology, and poor drug penetration across the BBB. Clinically, USP7 is highly overexpressed and contributes to tumor aggressiveness in glioma.

METHODS:

Native USP7 inhibitors (P22077 and P5091) exhibit potent cytotoxicity but suffer from poor solubility, suboptimal pharmacokinetics, and limited BBB permeability, restricting their translational potential. To overcome these limitations, we developed PLGA-based nanoparticles of both inhibitors (nP22077 and nP5091) and observed efficient encapsulation with better pharmacokinetic profiles.

RESULTS:

Nano-encapsulation enhanced anti-glioma potency by ~10-fold, with nP5091 showing superior P53 restoration, MDM2 suppression, DNA damage induction, and apoptosis across in vitro, in vivo, and ex vivo assays. In subcutaneous xenografts and a stringent stereotactic orthotopic glioma model, nP5091 achieved substantial tumor regression, minimal systemic toxicity, and significantly prolonged survival, supported by strong molecular evidence of P53 reactivation and apoptotic signaling.

CONCLUSION:

Collectively, this work establishes nano-enabled delivery of USP7 inhibitors as a robust, mechanistically driven therapeutic strategy capable of overcoming key pharmacological barriers and offering a promising avenue for future glioma treatment.

100 项与 USP7 inhibitors (Hybrigenics) 相关的药物交易

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