新颖USP7抑制剂Parthenolide的发现及抗结直肠肿瘤研究

	新颖USP7抑制剂Parthenolide的发现及抗结直肠肿瘤研究; Identification and anti-colorectal tumor study of novel USP7 inhibitor Parthenolide
	李雪
导师	李艳
摘要	It has been well established that the ubiquitin proteasome system (UPS) is one of the most important molecular targets for drug development. Deubiquitinating enzyme ubiquitin-specific peptidase 7 (USP7) is closely involved in various tumorigenesis by up-regulating multiple crucial cellular pathways, including Wnt/β-catenin, Sonic Hedgehog, NF-??B and Hippo signaling. USP7 inhibitors have shown great potential in suppressing tumor initiation and development by regulating the abundance and function of various oncoproteins and tumor suppressor protenins. Therefore, identifying and developing novel USP7 inhibitors is of great significance for tumor therapy. In this thesis, we performed an in vitro high throughput screen against numbers of small molecule chemicals and obtained a series of active compounds. Among them, the natural sesquiterpene lactone parthenolide (PTL) is a new type of chemical structure skeleton of USP7 inhibitors. Using fluorogenic Ub-AMC/Ub-Rho110, Ub-VME/Ub-PA labeling and Di-Ub hydrolysis assays, we proved that PTL can selectively inhibit USP7 activity. Further investigations using cellular thermal shift (CETSA), surface plasmon resonance (SPR), and mass spectrum (MS) assays revealed that PTL directly interacts with USP7. Consistent with the role of USP7 in stimulating Wnt signaling and carcinogenesis, PTL treatment inhibited the activity of Wnt signaling partly via increasing ubiquitination of β-catenin and accelerating the degradation of β-catenin through the proteasome. Moreover, using cell viability assay and cell apoptois assay, we found that PTL suppresses the proliferation of colorectal cancer cells and induces apoptosis in these cells. Additionally, we examined the effects of two other sesquiterpene lactones (costunolide and α-santonin) on USP7 and Wnt signaling and found that α-methylene-γ-butyrolactone might be the functional group of sesquiterpene lactone to inhibit USP7, which provides an important theoretical basis for the structural modification of PTL to improve its characteristic for the clinical application of PTL. PTL is a natural sesquiterpene lactone with many important pharmacological activities, especially the anti-tumor activity. It is of great importance to elucidate its mechanisms and molecular targets for promoting its clinical research and application. Our findings in this thesis revealed that PTL inhibits USP7 activity and Wnt/β-catenin signaling, identifying a potential mechanism by which PTL suppresses tumor growth. Our study not only enriched the antitumor mechanism of PTL, but also provided that sesquiterpene lactones might represent a novel suitable scaffold for developing USP7 inhibitors.
	2020-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74147
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	李雪. 新颖USP7抑制剂Parthenolide的发现及抗结直肠肿瘤研究, Identification and anti-colorectal tumor study of novel USP7 inhibitor Parthenolide[D],2020.

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