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

描述(由申请人提供)：癌症研究已经发生了革命性的变化，因为人们认识到，使肿瘤抑制基因的体细胞突变失活是驱动肿瘤发生过程的关键组成部分。虽然这种肿瘤抑制基因的发现对识别罕见的癌症易感家庭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，它们几乎没有发现(如果有的话)新药。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--将肿瘤抑制基因的发现转化为针对它们的疗法的最佳方法是什么？PTEN是一种典型的肿瘤抑制基因，通常在胶质母细胞瘤、子宫内膜癌、黑色素瘤、前列腺癌和其他类型的肿瘤中被突变失活。我们最近利用人体细胞基因打靶技术创建了人HCT116结肠癌细胞的等基因集，这些细胞集仅在存在或不存在内源性野生型PTEN基因时有所不同。在这里，我们建议使用这组细胞作为基于细胞的筛选的基础，以识别对PTEN缺陷细胞具有特异性细胞毒或细胞抑制作用的小分子。这些化合物将是研究PTEN抑癌途径的有用探针，并可能形成治疗PTEN突变癌症的基础。此外，我们建议创建额外的以PTEN基因为靶点的人类癌细胞的等基因组，作为第二次筛查，以确认在初步检测中获得的命中。具体目标#1：验证和实施基于细胞的筛选，以识别特定杀死PTEN缺陷的人类癌细胞的分子。具体目标#2：利用人类体细胞基因打靶来创造额外的等基因组人类癌细胞，只有在存在或不存在PTEN的情况下才不同。在这些新的细胞系中验证AIM#1中获得的命中结果。

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.