Novel Effectors of Colon Tumorigenesis

结肠肿瘤发生的新效应器

• 批准号: 8827270
• 负责人: Robert E. Lewis
• 金额: $ 30.96万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-12 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8827270
• 关键词: Actinobacteria class; Affect; Biological; Biological Assay; Biological Factors; Cell Survival; Cells; Characteristics; Chemicals; Colon Carcinoma; Colonic Neoplasms; Data; Development; Epithelial Cells; Epithelium; Evaluation; Exhibits; Future; Gene Expression; Gene Targeting; Genes; Goals; Growth; Habitats; Human; Knowledge; Lead; Libraries; Maintenance; Malignant Neoplasms; Marines; Mediating; Modeling; Molecular; Mus; Mutate; Neoplasm Metastasis; Normal Cell; Normal tissue morphology; Oncogenic; Outcome; Pathway interactions; Phenotype; Proteins; RNA Interference; Reference Standards; Research; Research Proposals; Resistance; Role; Scaffolding Protein; Screening Result; Signal Pathway; Signal Transduction; Small Interfering RNA; Testing; Therapeutic; Toxic effect; Tumor Cell Line; base; cancer therapy; cell growth; cell transformation; colon tumorigenesis; effective therapy; genome-wide analysis; high throughput screening; human KSR protein; in vitro testing; in vivo; inhibitor/antagonist; intercalation; microbial; neoplastic cell; new therapeutic target; novel; novel strategies; ras Proteins; scaffold; small molecule; targeted treatment; therapeutic target; tumor; tumorigenesis; tumorigenic

DESCRIPTION (provided by applicant): The central hypothesis of this research proposal is that new targets and compounds for cancer therapy can be coordinately revealed by a high throughput screen for genes and small molecules that mimic the effects of the molecular scaffold Kinase Suppressor of Ras 1 (KSR1). KSR1-/- mice and cells derived from those mice grow and develop normally but are resistant to tumorigenesis and transformation by oncogenic Ras. These observations suggest that KSR1, gene products downstream of KSR1, or gene products with functional characteristics similar to KSR1, may serve as targets for therapeutic manipulation in tumors bearing oncogenic Ras, but with reduced or minimal toxicity to normal tissue. We developed a Gene Expression High Throughput Screen (GE-HTS) that can coordinately identify effectors mimicking KSR1 function and small molecule inhibitors of those targets that selectively inhibit tumor cell growth, but not growth of normal colonic epithelium. Subsequent analysis demonstrated that human colon tumor cell lines expressing mutated, activated Ras exhibit KSR1-dependent expression of transcriptional regulators essential for maintenance of the transformed phenotype. Immortalized normal human colonic epithelial cells did not express these regulators. These data identify a previously unrecognized signaling network that promotes colon tumor cell survival. RNAi based GE- HTS will be used to define that network and test its potential as a therapeutic target by characterizing the role of transcriptional regulators and the identification of additional network effectors regulating KSR1-dependent tumorigenic potential. GE-HTS using a natural products library will be used to identify small molecule inhibitors of network effectors. These effectors and small molecules will be tested in vitro and in in vivo orthotopic tumor models to validate their ability to regulate tumor development and maintenance.

描述（由申请人提供）：本研究提案的中心假设是，通过高通量筛选模拟 Ras 1 分子支架激酶抑制剂作用的基因和小分子，可以协调揭示癌症治疗的新靶点和化合物（KSR1）。 KSR1-/- 小鼠和源自这些小鼠的细胞正常生长和发育，但对致癌 Ras 的肿瘤发生和转化具有抵抗力。这些观察结果表明，KSR1、KSR1下游的基因产物或具有与KSR1相似的功能特征的基因产物，可以作为具有致癌Ras的肿瘤的治疗操作靶点，但对正常组织的毒性降低或最小。我们开发了一种基因表达高通量筛选 (GE-HTS)，它可以协调识别模拟 KSR1 功能的效应子和那些选择性抑制肿瘤细胞生长但不抑制正常结肠上皮生长的靶标的小分子抑制剂。随后的分析表明，表达突变、激活的 Ras 的人类结肠肿瘤细胞系表现出 KSR1 依赖性转录调节因子的表达，这对于维持转化的表型至关重要。永生化的正常人结肠上皮细胞不表达这些调节因子。这些数据确定了以前未被识别的促进结肠肿瘤细胞存活的信号网络。基于 RNAi 的 GE-HTS 将用于定义该网络，并通过表征转录调节因子的作用和鉴定调节 KSR1 依赖性致瘤潜力的其他网络效应器来测试其作为治疗靶点的潜力。使用天然产物库的 GE-HTS 将用于识别网络效应器的小分子抑制剂。这些效应器和小分子将在体外和体内原位肿瘤模型中进行测试，以验证它们调节肿瘤发展和维持的能力。