Ubiquitin based therapy of aggressive cancer cell populations

描述（由申请人提供）：大多数细胞蛋白质的降解分别通过泛素E3连接酶和去泛素化酶（DUB）家族协调添加和去除泛素来调节。DUB从蛋白质中蛋白水解切割泛素分子，导致蛋白质活性、定位和功能的修饰。几种DUB在癌症中受到异常调节，包括研究最好的USP 7，其选择性抑制剂在癌症模型中具有活性。第二个DUB，USP 22，是另一个验证的抗癌靶点，是癌症死亡基因标签中的11个基因之一，是调节myc转录的人佐贺转录辅因子复合物的组分，也是p21、组蛋白脱乙酰酶Sirt 1和p53活性表达的调节因子。USP 22在口腔鳞状细胞癌、乳腺癌、非小细胞肺癌、结直肠癌和其他癌症中过表达，其表达与生存率呈负相关。与大多数其他DUB不同，USP 22仅作为多亚基复合物的组分表现出稳健的活性。最初的研究仅报道了作为2 MDa佐贺复合物的成员的活性，但最近已经证明USP 22在源自佐贺复合物的四蛋白DUB模块中表现出相似的活性。基于Progenra在DUB复合物方面的成功，本文建议开发一种HTS合规性测定法，以鉴定USP 22的新型抑制剂。在对Progenra的基于200 K成员多样性的小分子文库进行筛选后，将针对一组DUB和其他蛋白酶进一步表征感兴趣的化合物，并将通过测试一系列充分验证的药效学标志物的调节来探索细胞活性。主要目标是鉴定USP 22的新型抑制剂;具体里程碑包括：活性USP 22 DUB复合物的纯化、HTS合规USP 22测定格式的配置以及在细胞模型中鉴定具有活性的选择性USP 22抑制剂。最令人感兴趣的化合物将在第二阶段进行改进，以达到与DMPK和体内活性相关的药物化学优化。

DESCRIPTION (provided by applicant): The degradation of most cellular proteins is regulated by coordinated addition and removal of ubiquitin by families of ubiquitin E3 ligases and deubiquitylating enzymes (DUBs) respectively. DUBs proteolytically cleave ubiquitin molecules from proteins resulting in modifications of protein activity, localization and function. Several DUBs are aberrantly regulated in cancer, including the best studied, USP7, selective inhibitors of which are active in cancer models. A second DUB, USP22, is another validated anticancer target, being one of 11 genes in the death-from-cancer gene signature, a component of the human SAGA transcriptional cofactor complex regulating myc transcription, and a regulator of the expression of p21, the histone deacetylase Sirt 1, and p53 activity. USP22 is overexpressed in oral squamous cell carcinoma, breast, non-small cell lung, colorectal, and other cancers and its expression is inversely correlated with survival. Unlike most other DUBs, USP22 exhibits robust activity only as a component of a multi-subunit complex. Initial studies reported activity solely as a member of the 2MDa SAGA complex, but more recently it has been demonstrated that USP22 exhibits similar activity in a four-protein DUB module derived from the SAGA complex. Based on Progenra's success working with DUB complexes, it is proposed here to develop a HTS compliant assay to enable the identification of novel inhibitors of USP22. Following a screen of Progenra's 200K member diversity based library of small molecules, compounds of interest will be characterized further against a panel of DUBs and other proteases and cellular activity will be explored by testing the modulation of a series of well validated pharmacodynamic markers. The primary goal is to identify novel inhibitors of USP22; specific milestones include: purification of active USP22 DUB complex, configuration of an HTS compliant USP22 assay format and identification of selective USP22 inhibitors with activity in cellular models. The most interesting compounds will be advanced, in Phase II, to hit-to-lead medicinal chemistry optimization with associated DMPK and in vivo activity.