Specific Biochemical Inactivation of Oncogenic Ras

致癌 Ras 的特异性生化灭活

• 批准号: 6815288
• 负责人: JEFFREY E SETTLEMAN
• 金额: $ 31.89万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6815288
• 关键词: biochemistry; cell transformation; disease /disorder model; enzyme activity; gel filtration chromatography; genetically modified animals; guanine nucleotide binding protein; guanosinetriphosphatases; high throughput technology; laboratory mouse; neoplastic process; nucleoside diphosphate kinase; oncogenes; phosphotransferases; protein protein interaction; protein structure function; small molecule; tissue /cell culture; transfection

DESCRIPTION (provided by applicant): The Ras oncogene is a causative agent in about one-third of all human cancers, and there are no effective drug-based treatments available that specifically target the oncogenic Ras protein. We detected an activity in a crude E. coli extract that efficiently converts GTP-bound oncogenic Ras proteins to an inactive GDP bound form. The activity was purified and a single protein responsible for the activity was identified as nucleoside diphosphate kinase (NDK). We find that NDK can specifically inactivate several oncogenic Ras proteins, but not wild-type Ras, in vitro and in vivo. We propose to extend these findings to test the feasibility of biochemically inactivating oncogenic Ras in vivo as a means of inhibiting tumorigenesis. The Specific Aims of the proposed studies are: I. To establish the biochemical mechanism by which NDK promotes the specific inactivation of oncogenic forms of the Ras GTPase. This is expected to provide insights into the biochemical defect associated with oncogenic Ras proteins and potential strategies for promoting specific Ras inactivation. II. To assess the ability of NDK to antagonize the oncogenic actions of Ras in cell culture transformation assays and in a mouse model of K-Ras-induced tumors. Here, NDK will be utilized as a tool for examining the feasibility of promoting biochemical inactivation of Ras in vivo as a therapeutic strategy. III. To test the hypothesis that selective loss of NM23 (the human ortholog of NDK, which has been identified previously as a tumor/metastasis suppressor of unknown function) in human tumors is associated with increased potency of oncogenic forms of Ras. IV. To utilize a high throughput biochemical screening strategy to identify small molecules with the potential to facilitate inactivation of oncogenic forms of Ras. This will be performed in close collaboration with the Harvard Institute of Chemistry and Chemical Biology. Together, the proposed studies are expected to lead to the eventual development of a novel therapeutic approach for achieving specific targeting of human tumors that harbor oncogenic mutant forms of Ras.

描述（由申请人提供）：Ras 致癌基因是大约三分之一的人类癌症的致病因子，目前还没有专门针对致癌 Ras 蛋白的有效药物治疗方法。我们检测到大肠杆菌粗提取物中的一种活性，可有效地将 GTP 结合的致癌 Ras 蛋白转化为无活性的 GDP 结合形式。该活性被纯化，并且负责该活性的单一蛋白质被鉴定为核苷二磷酸激酶（NDK）。我们发现，在体外和体内，NDK 可以特异性地灭活几种致癌 Ras 蛋白，但不能灭活野生型 Ras。我们建议扩展这些发现，以测试体内生化灭活致癌 Ras 作为抑制肿瘤发生的手段的可行性。拟议研究的具体目标是： I. 建立 NDK 促进 Ras GTP 酶致癌形式特异性失活的生化机制。预计这将有助于深入了解与致癌 Ras 蛋白相关的生化缺陷以及促进特定 Ras 失活的潜在策略。二.旨在评估 NDK 在细胞培养转化试验和 K-Ras 诱导肿瘤小鼠模型中拮抗 Ras 致癌作用的能力。在这里，NDK 将被用作检查促进 Ras 体内生化失活作为治疗策略的可行性的工具。三．测试人类肿瘤中 NM23（NDK 的人类直系同源物，之前已被鉴定为功能未知的肿瘤/转移抑制因子）的选择性缺失与 Ras 致癌形式的效力增强相关的假设。四．利用高通量生化筛选策略来鉴定具有促进 Ras 致癌形式失活潜力的小分子。这将与哈佛大学化学与化学生物学研究所密切合作进行。总之，拟议的研究预计将最终开发出一种新的治疗方法，以实现针对含有 Ras 致癌突变形式的人类肿瘤的特异性靶向。