Structure Based Discovery of AKT Inhibitors

描述(由申请人提供)： AKT1(蛋白激酶B)是v-AKT癌基因的细胞同源基因，并且 代表多基因蛋白质的三种异构体之一-丝氨酸/苏氨酸 蛋白水解酶家族。一个或多个Akt基因的扩增和/或过表达 在胃癌、脑癌、乳腺癌、前列腺癌、 卵巢和胰腺。AKT活性高在伴有 肿瘤抑制基因PTEN的突变或缺失 作为一种磷脂酰肌醇3-磷酸酶。野生型PTEN在人中的表达 人胰腺癌/坏死瘤中肿瘤细胞系及AKT2反义基因的表达 异种移植显著地减少了细胞和肿瘤的生长，这表明 AKT作为治疗靶点的作用。这样做的总体目标是 因此，应用是开发AKT的异构体特异性抑制剂 通过使用分子建模和虚拟筛选化合物 文库与基于同源二聚化的独特筛选试验相结合 AKT的/Soform特异的N-末端DNAAIN(AH域)。先导药物 在此筛查中确定的将被评估其抑制肿瘤的能力 细胞生长，诱导细胞凋亡，阻断AKT激活 转磷酸化。此应用程序将解决以下假设 AKT二聚体的阻断将抑制其活性和下游 抑制肿瘤细胞增殖的效应通路和 激活细胞凋亡。这一假设将通过以下方式得到解决 具体目标：1)完善我们的AKT1模型并将其用于构建 由AH结构域相互作用产生的同源二聚体，2)鉴定 位于AKT界面的AKT AH结构域的结构区域 同源二聚体和使用化合物文库(NCI、ACD)的虚拟筛选 识别能够与这些二聚作用相互作用的小分子 区域，以及3)测试那些显示出最佳评分功能的化合物 与AH结构域结合以抑制AKT二聚化的能力，以及 因此，AKT在体外被激活。基于后一种结果， 结构-活性关系(SAR)数据将通过化学方法生成 修饰先导分子以提高化合物的活性。 对AKT1 AH结构域结合口袋的活性结构建模将为 以迭代的方式用于指导化合物合成以及建议 利用组合化学建立可能的化合物文库 方法：研究方法。

DESCRIPTION (provided by applicant): AKT1 (protein kinase B) is the cellular homolog of the v-akt oncogene, and represents one of three isoforms of a multigene protein-serine/threonine kinase family. Gene amplification and/or overexpression of one or more Akt isoforms have been noted in cancers of the stomach, brain, breast, prostate, ovary and pancreas. High AKT activity is particularly evident in tumors with mutations or deletion of the tumor suppressor, PTEN, which functions primarily as a phosphoinositide 3-phosphatase. Expression of wild-type PTEN in human tumor cell lines or an AKT2 antisense cDNA in a human pancreatic carc/noma xenograft dramatically reduced cell and tumor growth, respectively, suggesting the utility of AKT as a therapeutic target. The broad objective of this application, therefore, is to develop isoform-specific inhibitors of AKT through the use of molecular modeling and virtual screening of compound libraries coupled with a unique screening assay based on homodimerization of the/soform-specific N-terminal donaain (AH domain) of AKT. Lead drugs identified in this screen will be assessed for their ability to inhibit tumor cell growth, induce apoptosis and block AKT activation via transphosphorylation. This application will address the hypothesis that interruption of AKT dimerization will inhibit its activity and downstream effector pathways leading to inhibition of tumor cell proliferation and activation of apoptosis. This hypothesis will be addressed by the following Specific Aims: 1) To refine our AKT1 model and to use it in construction of the homodimer resulting from interaction of the AH domains, 2) To identify structural regions in the AKT AH domain located at the interface of the AKT homodimer and to use virtual screening of compound libraries (NCI, ACD) to identify small molecules capable of interacting with these dimerization regions, and 3) To test those compounds showing the best scoring function for binding to the AH domain for their ability to inhibit AKT dimerization, and thus, activation of AKT in vitro. Based upon the latter results, structure-activity relationship (SAR) data will be generated by chemical modificationm of the lead molecules in order to improve compound activity. Modeling of active structures to the AKT1 AH domain binding pocket will be used in an iterative manner to guide compound synthesis as well as to suggest possible compound libraries to be created using combinatorial chemistry methods.