Ubiquitin based therapy of aggressive cancer cell populations

描述（由申请人提供）：大多数细胞蛋白的降解是由泛素E3连接酶和去泛素化酶（DUBs）家族分别协调添加和去除泛素来调节的。DUBs蛋白水解地从蛋白质中切割泛素分子，从而改变蛋白质的活性、定位和功能。一些dub在癌症中被异常调节，包括研究得最好的USP7，它的选择性抑制剂在癌症模型中是活跃的。第二个DUB， USP22，是另一个被证实的抗癌靶点，是癌症死亡基因标志中的11个基因之一，是调节myc转录的人类SAGA转录辅助因子复合体的一个组成部分，也是p21表达、组蛋白去乙酰化酶sirt1和p53活性的调节剂。USP22在口腔鳞状细胞癌、乳腺癌、非小细胞肺癌、结直肠癌等癌症中过表达，其表达与生存呈负相关。与大多数其他dub不同，USP22仅作为多亚基复合物的组成部分表现出强大的活性。最初的研究报告仅作为2MDa SAGA复合物的成员具有活性，但最近已经证明USP22在SAGA复合物衍生的四蛋白DUB模块中具有类似的活性。基于Progenra在DUB复合物方面的成功，本文建议开发一种符合HTS的检测方法，以鉴定新的USP22抑制剂。在对Progenra的200K成员多样性小分子文库进行筛选后，将根据dub和其他蛋白酶进一步对感兴趣的化合物进行表征，并通过测试一系列经过验证的药效学标记物的调节来探索细胞活性。主要目标是鉴定新的USP22抑制剂；具体里程碑包括：活性USP22 DUB复合物的纯化，符合HTS标准的USP22检测格式的配置，以及在细胞模型中具有活性的选择性USP22抑制剂的鉴定。最有趣的化合物将在II期进行先导药物化学优化，并具有相关的DMPK和体内活性。

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.