Screening for adjuvant gliobalstoma therapeutics

胶质母细胞瘤辅助治疗的筛选

• 批准号: 9244081
• 负责人: BAKHOS A TANNOUS
• 金额: $ 37.41万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9244081
• 关键词: Adjuvant; Adjuvant Therapy; Adult; Alkylating Agents; Apoptosis; Biological Assay; Cell Survival; Cells; Central Nervous System Neoplasms; Cessation of life; Chemicals; DNA; DNA Adducts; DNA Repair; Data Analyses; Diagnosis; Dose; Drug Targeting; Drug resistance; Enzymes; Failure; Fibroblasts; Futile Cycling; Genetic; Genetic Transcription; Genotype; Glioblastoma; Glioma; Guanine; Lead; Lesion; Libraries; Luciferases; Malignant - descriptor; Malignant neoplasm of brain; Mediating; Methylation; Molecular; Newly Diagnosed; Normal Cell; Operative Surgical Procedures; Patients; Pharmaceutical Chemistry; Pharmaceutical Preparations; Phase II Clinical Trials; Phenotype; Positioning Attribute; Preclinical Drug Evaluation; Primary Brain Neoplasms; Progression-Free Survivals; Radiation; Randomized; Recurrence; Recurrent tumor; Reporter; Resistance; Source; Specificity; Stem cells; System; Testing; Therapeutic; Time; Transferase; Triage; Tumor Initiators; Update; Validation; analog; astrocyte progenitor; base; cell killing; conventional therapy; counterscreen; cytotoxicity; drug candidate; experimental study; high throughput screening; killings; neoplastic cell; novel; novel therapeutics; phase 3 study; promoter; public health relevance; relating to nervous system; response; screening; small molecule; standard of care; stem cell population; stem cell therapy; success; temozolomide; tumor; tumor initiation

 DESCRIPTION (provided by applicant): More than half of the 18,000 patients diagnosed with malignant primary brain tumors in the U.S. each year have glioblastoma (GBM), the most common and most aggressive primary malignant brain tumor in adults. Over the last two decades, the major breakthrough in the treatment for GBM has been the addition of the DNA alkylating agent temozolomide (TMZ) to the standard of care (surgery and radiation) yielding an increase in the median survival from 12.1 months to 14.6 months. Despite this advancement, 90% of GBM patients die within 5 years, a colossal failure attributed to TMZ resistance. One of the major predictor of GBM response to TMZ is the MGMT promoter methylation status. This enzyme removes the DNA adduct, induced by TMZ, leading to cell survival. Thus, patients whose tumors have transcriptional silencing of the MGMT gene, mediated by promoter methylation, are most likely to benefit from TMZ. Given that all glioblastomas recur to a tumor lesion with acquired resistance to TMZ, novel adjuvant therapies could be highly beneficial to GBM patients. Recently, it was shown that a subpopulation of tumor cells, called glioblastoma stem cells (GSCs or tumor initiating cells), are responsible for tumor recurrence and resistance to conventional therapies. In this proposal, we will use a multiplex secreted reporter system for high-throughput screening to find drugs that either synergizes with TMZ on GBM stem cells from both newly diagnosed and recurrent tumors, irrespective of the MGMT status, or that kills a specific GBM stem cells subtype. We will simultaneously screen in the same well for drugs which act on three different GBM stem cells subpopulations: (1) obtained from newly diagnosed tumors with methylated MGMT promoter; (2) newly diagnosed GBM with unmethylated MGMT promoter; (3) recurrent TMZ-resistant tumors. We will use primary GBM stem cells dissociated from patient tumors sections and grow them as neural spheres which maintain the phenotype/genotype of the original tumor. Dose- and time-dependent experiments of our drug hits will be performed and validated using secondary screening assays in culture. A set of analogues of the most promising hits will be purchased, if available commercially, or synthesized by medicinal chemistry to make these drugs "fit-for-purpose", to facilitate their study in cells, and for pull down assays to find targets of drug hits. Finally, specificity of drug hits o glioblastoma will be tested using a panel of normal cells and stem cells in culture.

 描述(申请人提供)：在美国每年确诊的18,000名恶性原发脑瘤患者中，超过一半的人患有胶质母细胞瘤(GBM)，这是成人最常见和最具侵袭性的原发恶性脑瘤。在过去的二十年里，治疗GBM的主要突破是将DNA烷化剂替莫唑胺(TMZ)添加到治疗标准(手术和放射治疗)中，使中位生存期从12.1个月增加到14.6个月。尽管取得了这些进展，但90%的GBM患者在5年内死亡，这是一个巨大的失败，可归因于对TMZ的耐药性。MGMT启动子甲基化状态是GBM对TMZ反应的主要预测因子之一。这种酶去除TMZ诱导的DNA加合物，导致细胞存活。因此，由启动子甲基化介导的MGMT基因转录沉默的肿瘤患者最有可能受益于TMZ。考虑到所有胶质母细胞瘤都复发于对TMZ获得性耐药的肿瘤病变，新的辅助治疗对GBM患者可能非常有益。最近，有研究表明，肿瘤细胞的一个亚群，称为胶质母细胞瘤干细胞(GSCs或肿瘤启动细胞)，与肿瘤复发和对传统治疗的耐药性有关。在这项提案中，我们将使用多重分泌报告系统进行高通量筛选，以寻找与TMZ对来自新诊断和复发的肿瘤的GBM干细胞的协同作用的药物，无论MGMT状态如何，或者杀死特定的GBM干细胞亚型。我们将同时筛选作用于三种不同GBM干细胞亚群的药物：(1)来自新诊断的具有MGMT启动子甲基化的肿瘤；(2)新诊断的具有未甲基化MGMT启动子的GBM；(3)复发的TMZ耐药肿瘤。我们将使用从患者肿瘤切片分离的原代GBM干细胞，并将它们培养成神经球，保持原始肿瘤的表型/基因。我们的药物点击将进行剂量和时间依赖的实验，并使用培养中的二次筛选试验进行验证。将购买一套最有希望的热门药物的类似物，如果可以从商业上获得，或通过药物化学合成，使这些药物“适合用途”，以促进他们的研究。 在细胞中，并用于下拉分析以寻找药物靶点。最后，将使用一组正常细胞和培养中的干细胞来测试胶质母细胞瘤药物的特异性。