Deciphering synergistic combinatorial targets in glioma

破译神经胶质瘤的协同组合靶点

• 批准号: 7893667
• 负责人: W K ALFRED Yung
• 金额: $ 26.54万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-08 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7893667
• 关键词: AEE 788; Animal Model; Animals; Apoptosis; CCI-779; Cell Death; Cell Proliferation; Cells; Clinical Trials; Combined Modality Therapy; Complex; Data; Disease; Dominant-Negative Mutation; Drug Combinations; Drug Delivery Systems; Effectiveness; Endothelial Cells; Epidermal Growth Factor Receptor; Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor; Erlotinib; Evaluation; Event; Gefitinib; Gene Silencing; Gene Targeting; Genes; Glioblastoma; Glioma; Gliomagenesis; Goals; Growth Factor; Implant; In Vitro; Individual; Knowledge; Laboratories; Lead; Lentivirus Vector; Libraries; Malignant - descriptor; Medicine; Methodology; Molecular; Molecular Profiling; Molecular Target; Mutation; Outcome; PI3K/AKT; Pathway Analysis; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Phenotype; Pilot Projects; Protein Tyrosine Kinase; Proteins; Proto-Oncogene Proteins c-akt; Receptor Protein-Tyrosine Kinases; Refractory; Research Personnel; Sampling; Screening procedure; Signal Pathway; Signal Transduction; Sirolimus; Small Interfering RNA; Staging; TP53 gene; Techniques; Testing; Therapeutic; Treatment Efficacy; Tumor Suppressor Genes; Vascular Endothelial Growth Factors; Work; angiogenesis; combinatorial; conventional therapy; drug testing; genome-wide; glioma cell line; improved; in vivo; inhibitor/antagonist; mTOR Inhibitor; meetings; neoplastic cell; novel; programs; prototype; receptor; response; small molecule; subcutaneous; success; therapeutic target; tumor

DESCRIPTION (provided by applicant): Glioblastomas is the most malignant form of primary gliomas. Despite the advance in medicine, it remains refractory to conventional therapies. Recent progress in understanding of molecular events leading to glioma genesis provides alternative therapeutic targets for management of gliomas. Several novel small molecules targeting various signaling nodes along receptor tyrosine kinases (RTKs) and PTEN-PI3K-akt pathway have been developed and are currently in different stages of testing, including EGFR inhibitors like Tarceva, Iressa, and AEE788 as well as mTOR inhibitors such as Rapamycin and CCI-779. However, they have met with only limited success in early phase l/ll clinical trials when used alone, most likely because other compensatory or collateral pathways negate the therapeutic efficacy of inhibiting a single signal node. The logical next step, is to identify drugs that would block these pathways so that when given in combination, they elicit enhanced anti-tumor effect. Our long-term goal is to identify specific molecular agents that, when used in combination, would improve the therapeutic outcome for glioblastoma. This proposal seeks to use modern siRNA gene-silencing techniques to identify targets whose inactivation when combined with small molecule inhibitors would confer synergistic anti-tumor activity. Following are specific aims to achieve this goal. Specific Aim 1: To identify the molecular targets or pathways whose disruption in combination with lead drug treatment will result in a lethal phenotype. Our working hypothesis is that silencing overlapping pathways or compensatory activated in response to treatment with a small molecule inhibitor (lead drug) will result in cell death. Using both a siRNA library and a signaling pathway drug, a genome-wide microarray screen will be employed to identify targets or pathways that when silenced will sensitize cells to drug-induced cell death. We expect to identify one or more targets for each of the four drugs tested. Specific Aim 2: To validate the targets or pathways whose inactivation sensitizes tumor cells to drug-induced cell death in vitro. Our working hypothesis is that inhibiting the targets identified in aim 1 will synergistically enhance the anti-tumor effect of the lead drug in vitro. Targets identified in aim 1 will be validated by 1) combining inactivation of targets by individual siRNA with lead drug treatment; 2) combining inactivation of targets with commercially available drug and lead drug treatment; 3) combining inactivation of targets by a dominant-negative constructs with lead drug treatment;. 4) assessment of lead drug effect on a battery of glioma cell lines; and 5) In vitro target evaluation with reverse phase protein lysate array (RPPA). Specific Aim 3: To evaluate the combined therapeutic efficacy of lead drug and target gene inactivation in vivo. Our working hypothesis is that one or more of the targets validated in vitro will exert drug-synergy when tested in animal models. The in vivo therapeutic efficacy of drug treatment with target gene inactivation will be tested in both intracranial and subcutaneous animal models. Tumor cells stably expressing siRNA against the target gene will be implanted into animals followed by lead drug treatment. For those targets whose inactivation could be achieved by using small molecules, animals receiving unmodified tumor cells will be treated with drug and small molecules. Tumor size and animal survival will be assessed to evaluate the therapeutic efficacy of combination treatments. The activity of downstream effector genes will be examined by reverse phase protein lysate array (RPPA). We expect that the results will not only advance our knowledge of the association between comp signal pathways and response to a particular targeted therapy but also increase the range of options for treating glioblastoma with combination therapy.

描述（申请人提供）：胶质母细胞瘤是原发性胶质瘤中最恶性的一种。尽管医学上取得了进步，但传统疗法仍然难以治愈。最近对导致胶质瘤发生的分子事件的了解进展为胶质瘤的治疗提供了替代的治疗靶点。一些靶向受体酪氨酸激酶（rtk）和PTEN-PI3K-akt通路上各种信号节点的新型小分子已经开发出来，目前处于不同的测试阶段，包括EGFR抑制剂如特罗凯、易瑞沙和AEE788，以及mTOR抑制剂如雷帕霉素和CCI-779。然而，当单独使用时，它们在早期i /ll期临床试验中只取得了有限的成功，很可能是因为其他代偿或侧枝通路否定了抑制单个信号节点的治疗效果。顺理成章的下一步是找出能够阻断这些通路的药物，这样当联合用药时，它们就能产生更强的抗肿瘤效果。我们的长期目标是确定特定的分子药物，当联合使用时，将改善胶质母细胞瘤的治疗结果。该建议寻求使用现代siRNA基因沉默技术来鉴定靶标，当与小分子抑制剂联合使用时，其失活将赋予协同抗肿瘤活性。以下是实现这一目标的具体目标。特异性目标1：确定分子靶点或途径，其破坏与铅药物治疗联合将导致致命表型。我们的工作假设是，沉默重叠通路或补偿激活响应于小分子抑制剂（先导药物）的治疗将导致细胞死亡。使用siRNA文库和信号通路药物，全基因组微阵列筛选将被用来识别靶点或途径，当沉默时将使细胞对药物诱导的细胞死亡敏感。我们期望为四种测试药物中的每一种确定一个或多个靶点。特异性目的2：在体外验证其失活使肿瘤细胞对药物诱导的细胞死亡致敏的靶点或途径。我们的工作假设是，抑制aim 1中确定的靶点将协同增强体外先导药物的抗肿瘤作用。在目标1中确定的靶标将通过以下方式进行验证：1)将单个siRNA灭活靶标与先导药物治疗相结合；2)将靶标失活与市售药物和先导药物治疗相结合；3)优势阴性结构体灭活靶点与先导药物治疗相结合；4)脑胶质瘤细胞系铅类药物效应评价；5)反相蛋白裂解物阵列（RPPA）体外靶点评价。特异性目的3：评价铅药联合靶基因灭活在体内的联合治疗效果。我们的工作假设是，在体外验证的一个或多个靶点在动物模型中测试时将发挥药物协同作用。靶基因失活药物治疗的体内治疗效果将在颅内和皮下动物模型中进行测试。将稳定表达针对靶基因的siRNA的肿瘤细胞植入动物体内，然后进行先导药物治疗。对于那些可以通过小分子实现失活的靶点，接受未修饰肿瘤细胞的动物将使用药物和小分子治疗。将评估肿瘤大小和动物存活率，以评估联合治疗的疗效。下游效应基因的活性将通过反相蛋白裂解物阵列（RPPA）检测。我们期望这一结果不仅能提高我们对比较信号通路与特定靶向治疗反应之间关系的认识，而且还能增加用联合治疗胶质母细胞瘤的选择范围。