Cell-Based Screens for Cancer:Targeting PTEN (RMI)

描述（由申请人提供）：由于认识到肿瘤抑制基因中的失活体细胞突变是驱动肿瘤发生过程的关键组成部分，癌症研究发生了革命性变化。 虽然这些肿瘤抑制基因的发现对鉴定罕见癌症易感家族中的高危个体具有深远的意义，并有助于更好地理解肿瘤进展的生物学机制，但到目前为止，它们导致了很少（如果有的话）新药物的发现。 学术界和制药公司的研究人员目前正在努力解决这个难题-什么是将肿瘤抑制基因的发现转化为靶向治疗的最佳方法？PTEN是一种原型肿瘤抑制基因，通常在胶质母细胞瘤、子宫内膜癌、黑色素瘤、前列腺癌和其他肿瘤类型中因突变而失活。 我们最近采用了人体细胞基因靶向来创建人HCT 116结肠癌细胞的等基因组，其差异仅在于其内源性野生型PTEN基因的存在或不存在。 在这里，我们建议采用这组细胞作为基于细胞的筛选的基础，以确定对PTEN缺陷细胞具有特异性细胞毒性或细胞生长抑制作用的小分子。 此类化合物将是用于研究PTEN肿瘤抑制途径的有用探针，并且可能形成用于治疗携带PTEN突变的癌症的治疗剂的基础。 此外，我们建议创建额外的等基因组的PTEN基因靶向的人癌细胞作为二次筛选，以确认在主要测定中获得的命中。 具体目标1：该研究的目的是建立一种基于细胞的筛选方法，用于鉴定特异性杀死PTEN缺陷型人类癌细胞的分子。 具体目标#2：采用人类体细胞基因靶向来创建仅在存在或不存在PTEN方面不同的人类癌细胞的额外等基因组。 在这些新细胞系中验证目标#1中获得的命中。

DESCRIPTION (provided by applicant): Cancer research has been revolutionized by the realization that inactivating somatic mutations in tumor suppressor genes are a key component that drives the process of tumorigenesis. While the discovery of such tumor suppressor genes have had profound implications for identification of at-risk individuals in rare cancer prone-families and have contributed to a better understanding of the biological mechanisms of tumor progression, thus far they have led to the discovery of few (if any) new drugs. Academic and pharmaceutical company researchers are currently grappling with this difficult question - what are the best ways to translate the discovery of tumor suppressor genes into therapeutics that target them? PTEN is a prototype tumor suppressor gene commonly inactivated by mutations in glioblastoma, endometrial cancer, melanoma, prostate cancer, and other tumor types. We have recently employed human somatic cell gene targeting to create isogenic sets of human HCT116 colon cancer cells that differ only in the presence or absence of their endogenous wild-type PTEN genes. Here we propose to employ this set of cells as the basis of a cell-based screen to identify small molecules that are specifically cytotoxic or cytostatic towards PTEN-deficient cells. Such compounds would be useful probes for study of the PTEN tumor suppressor pathway and might form the basis of therapeutics for treatment of cancers harboring mutations in PTEN. Furthermore, we propose to create additional isogenic sets of PTEN gene-targeted human cancer cells to function as secondary screens for confirmation of the hits obtained in the primary assay. Specific Aim #1: Validate and implement a cell-based screen for the identification of molecules that specifically kill PTEN-deficient human cancer cells. Specific Aim #2: Employ human somatic cell gene targeting to create additional isogenic sets of human cancer cells differing only in the presence or absence of PTEN. Validate the hits obtained in Aim #1 in these new cell lines.