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（由申请人提供）：美国每年诊断为恶性原发性脑肿瘤的18，000名患者中有一半以上患有胶质母细胞瘤（GBM），这是成人中最常见和最具侵袭性的原发性恶性脑肿瘤。在过去的二十年中，GBM治疗的重大突破是将DNA烷化剂替莫唑胺（TMZ）添加到标准治疗（手术和放射）中，使中位生存期从12.1个月增加到14.6个月。尽管取得了这一进展，但90%的GBM患者在5年内死亡，这是一个巨大的失败，归因于TMZ耐药。GBM对TMZ反应的主要预测因素之一是MGMT启动子甲基化状态。这种酶去除由TMZ诱导的DNA加合物，导致细胞存活。因此，患者的肿瘤有转录沉默的MGMT基因，启动子甲基化介导的，是最有可能受益于TMZ。鉴于所有胶质母细胞瘤复发的肿瘤病变获得性耐药TMZ，新的辅助治疗可能是非常有益的GBM患者。最近，研究表明，一种称为胶质母细胞瘤干细胞（GSC或肿瘤起始细胞）的肿瘤细胞亚群负责肿瘤复发和对常规疗法的抗性。在这项提案中，我们将使用一种多重分泌报告系统进行高通量筛选，以找到与TMZ协同作用于新诊断和复发肿瘤的GBM干细胞的药物，无论MGMT状态如何，或者杀死特定的GBM干细胞亚型。我们将在同一孔中同时筛选作用于三种不同GBM干细胞亚群的药物：（1）从新诊断的具有甲基化MGMT启动子的肿瘤获得;（2）新诊断的具有未甲基化MGMT启动子的GBM;（3）复发性TMZ耐药肿瘤。我们将使用从患者肿瘤切片中分离的原代GBM干细胞，并将其生长为神经球，其保持原始肿瘤的表型/基因型。我们的药物命中的剂量和时间依赖性实验将使用培养物中的二次筛选测定进行和验证。将购买一套最有希望的命中类似物，如果可以在商业上获得，或通过药物化学合成，使这些药物“适合目的”，以促进其研究 在细胞中，并用于下拉测定以找到药物命中的靶点。最后，将使用培养的一组正常细胞和干细胞测试药物对胶质母细胞瘤的特异性。