去泛素化酶在肿瘤发生发展过程中发挥着关键的调控作用。USP15是去泛素化酶之一，在多种肿瘤中表达异常，导致TGFbeta等信号通路过度激活，加速肿瘤的发生发展与转移，因此被认为是一个新型抗肿瘤药物靶点。但目前还未见特异性USP15抑制剂报道，本课题前期研究发现一类新型四氢-beta-咔啉类化合物可作为潜在的特异性USP15抑制剂。本项目拟在前期工作基础上设计、合成与优化此类酰基四氢-beta-咔啉类化合物，并在体内外评价其抗肿瘤作用及探索分子作用机制：首先是构建结构多样性的酰基四氢-beta-咔啉类化合物，通过结构优化总结构效关系；其次是考察目标化合物对去泛素化水平的影响及对肿瘤细胞增殖和迁移等的抑制作用；重点评估候选化合物在数个小鼠生长和转移模型中的效果。最终获得一类USP15选择性抑制剂作为抗肿瘤先导化合物并系统阐明相关的分子机制，为候选药物的系统临床前研究奠定坚实基础。

Deubiquitinating enzymes (DUBs) play a crucial modulating role against tumorigenesis and development. Ubiquitin specific protease 15 (USP15), as one of key deubiquitinating enzymes, is overexpressed in many cancers and led to excessive activation of TGFbeta as well as other cancer associated signaling pathways, which would accelerate tumorigenesis and progression, therefore USP15 is regarded as one of novel anticancer drug targets. However, No specific USP15 inhibitor is reported up to date, our previous research results indicated that a novel type of potential specific USP15 inhibitors was discovered through screening and structure optimization. Based on those results, the objective of this proposal is to design, synthesis and optimization of novel tetrahydro-beta-carbolines for developing lead compound of one type of specific USP15 inhibitors as well as evaluating its effects and mechanisms against tumor growth and metastasis in vitro and in vivo: firstly a novel series of aryl tetrahydro-beta-carbolines with structure-diversity will be designed and synthesized and the structure-activity relationship will be summarized. Secondly the effects of candidate compounds will be explored against deubiquitinase level of target proteins and inhibition of tumor cell proliferation and migration. Their in vivo effects will be further evaluated on several tumor growth and metastasis mice models and one type of specific USP15 inhibitors as novel anticancer lead compound will be finally identified and their molecular mechanisms will be explored in detail, which will lay a solid preclinical foundation for the drug candidate.