Screening for adjuvant gliobalstoma therapeutics

胶质母细胞瘤辅助治疗的筛选

基本信息

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
项目类别：
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

项目摘要

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（由适用提供）：每年在美国诊断出患有恶性原发性脑肿瘤的18,000例患者中，有超过一半的患者患有胶质母细胞瘤（GBM），这是成年人中最常见和最具侵略性的原发性恶性脑肿瘤。在过去的二十年中，GBM治疗的主要突破是将DNA烷基化剂替莫唑胺（TMZ）添加到护理标准（手术和辐射）中，其中位生存率从12.1个月增加到14.6个月。尽管有这一进步，但90％的GBM患者在5年内死亡，这归因于TMZ耐药性。 GBM对TMZ响应的主要预测指标之一是MGMT启动子甲基化状态。该酶消除了由TMZ诱导的DNA加合物，导致细胞存活。那就是由肿瘤对MGMT基因进行转录沉默的患者，该基因介导的甲基化介导的患者最有可能受益于TMZ。鉴于所有具有对TMZ耐药性的肿瘤病变复发的胶质母细胞瘤，新型调整疗法可能对GBM患者非常有益。最近，结果表明，称为胶质母细胞瘤干细胞（GSC或肿瘤引发的细胞）的肿瘤细胞的亚群是导致肿瘤复发和对常规疗法的抗性。在此提案中，我们将使用多重分泌的报告基因系统进行高通量筛查，以查找来自新诊断和复发性肿瘤的GBM干细胞上与TMZ协同作用的药物，而与MGMT状态无关，或者杀死特定的GBM干细胞。我们将简单地筛选出对三种不同GBM干细胞亚群作用的药物的筛选：（1）从新诊断为甲基化的MGMT启动子的肿瘤中获得；（2）新诊断为使用未甲基化的MGMT启动子的GBM；（3）复发性TMZ耐药性肿瘤。我们将使用与患者肿瘤切片分离的原代GBM干细胞，并作为维持原始肿瘤表型/基因型的神经球体生长。使用培养物中的二级筛选测定法，将对我们的药物打击的剂量和时间依赖性实验进行验证。如果商业上可用或由医学化学合成，以使这些药物“适合用途”，以促进他们的研究在细胞中，用于下拉测定以找到毒品击中的靶标。最后，将使用一组正常细胞和培养物中的干细胞来测试药物命中的特异性O胶质母细胞瘤。