The Role of Bcl2L12 in the Genesis of Malignant Glioma

Bcl2L12 在恶性胶质瘤发生中的作用

基本信息

批准号：
7486342
负责人：
Alexander H. Stegh
金额：
$ 9万
依托单位：
DANA-FARBER CANCER INST
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-08-17 至 2009-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7486342
关键词：
19q Address Alleles Anaplastic astrocytoma Apoptosis Apoptotic Applications Grants Area Astrocytes Binding Biochemical Biological Biological Assay Biological Models Biology Brain Candidate Disease Gene Caspase Cell Lineage Cells Cessation of life Chromosomes Clinical Colon Complement Complementary DNA Computer Simulation Condition Coupled Cultured Cells Data Depth Development Diagnosis Disease Elements Engineering Essential Genes Event Extramural Activities Follicular Lymphoma Foundations Future Gastrointestinal Stromal Tumors Gene Expression Profile Gene Targeting Gene Transfer Techniques Genes Genetic Genetically Engineered Mouse Genome Genomics Genus Cola Glioblastoma Glioma Goals Growth Hodgkin Disease Human In Vitro Inhibition of Apoptosis Investigation Knock-out Knockout Mice Lead Lesion Lymphoma Maintenance Malignant - descriptor Malignant Glioma Malignant Neoplasms Malignant neoplasm of brain Mediating Mesothelioma Microvascular Proliferation Mitochondria Modality Modeling Modification Molecular Molecular Analysis Molecular Profiling Monitor Mus Necrosis Neurons Normal tissue morphology Nucleoplasm Oncogene Proteins Oncogenes Oncogenic Outcome Pathogenesis Pathway interactions Physiological Pliability Principal Investigator Property Prostate Protein p53 Proteins RNA Interference Reporting Research Resistance Role Sampling Signal Transduction Specimen Stem cells Structure Subgroup System TP53 gene Technology Testing Therapeutic Therapeutic Intervention Thyroid Gland Tissues Toxic effect Transactivation Transcriptional Activation Transcriptional Regulation Translations Transplantation Up-Regulation Validation base brain tissue c-myc Genes caspase-3 caspase-7 cell type chromatin immunoprecipitation drug development gain of function high throughput screening in vivo in vivo Model indexing inhibitor/antagonist large cell Diffuse non-Hodgkin&apos s lymphoma liposarcoma loss of function lung Carcinoma mouse model mutant neoplastic cell nerve stem cell novel polypeptide pre-clinical programs research study small molecule stem success therapeutic target tumor tumor growth tumor initiation tumorigenic

项目摘要

DESCRIPTION (provided by applicant): Glioblastoma multiforme (GBM), the most aggressive manifestation of malignant gliomas, are characterized by microvascular proliferation, necrosis, extreme resistance to all extant therapeutic modalities and a neurologically destructive course culminating in death often within 12 months of diagnosis. Major conceptual gaps remain on the mechanistic level including how the classical genetic lesions contribute to these phenotypic aspects. To address this issue, we performed oncogenomic analyses of a large panel of human GBMs by array-CGH and expression profiling in an effort to gain a more comprehensive view of the genetic events underlying GBM development. In the course of characterizing a region of gain on chromosome 19q, we identified Bcl2L12 (for Bcl2-Like-12) as a glioma oncogene that is over-expressed in virtually all GBM samples, yet low or absent in low-grade disease and normal tissue. Extensive biochemical studies have established that Bcl2L12 functions as an anti-apoptotic protein in primary astrocytic cultures by inhibiting post-mitochondrial caspase-3 and caspase-7 activation. Since inhibition of apoptosis at the post- mitochondrial level is known to block apoptosis but promotes necrosis, Bcl2L12 over-expression in GBM may provide a rational explanation for a prime paradox in the biology of this disease - apoptosis resistance yet florid necrosis - and points to Bcl2L12 up-regulation as a key progression event in malignant glioma. In addition to its cytosolic caspase-3/7 inhibitory activity, Bcl2L12 resides in the nucleoplasm where it interacts with p53 and blocks p53-mediated transactivation. To analyze Bcl2L12-modulated pathways in cell culture- based assays in more detail and to genetically validate these findings in vivo, this grant proposal aims to elucidate further the molecular basis of Bcl2L12's oncogenic activity through detailed structure-function analyses. We will employ cell culture-based assays and orthotopic SCID explant tumor models using genetically engineered neuronal stem cells and mature cortical astrocytes to dissect apoptosis- and p53 modulatory activities. Furthermore, we will characterize in depth the molecular mechanism of p53 inhibition that defines yet another oncogenic activity of Bcl2L12 through detailed studies of p53-mediated transcriptional regulation. Finally, the consequences of Bcl2L12 inactivation for the development of GBM will be assessed using conditional Bcl2L12 knockout mice that may serve as an in vivo platform on which to assess consequence of pharmacological inactivation of Bcl2L12 for malignant glioma therapy. The continued lack of success in treating high-grade gliomas has prompted a reevaluation of all aspects of glioma drug development. This grant proposal aims to specifically address the currently unmet needs in the development of effective glioma therapies by refining the molecular understanding of the disease and by developing more accurate in vitro and in vivo glioma model system.

描述（由申请人提供）：多形性胶质母细胞瘤 (GBM) 是恶性胶质瘤最具侵袭性的表现，其特征是微血管增殖、坏死、对所有现有治疗方式的极度抵抗以及神经系统破坏性病程，通常在诊断后 12 个月内最终导致死亡。主要的概念差距仍然存在于机械层面，包括经典的遗传损伤如何影响这些表型方面。为了解决这个问题，我们通过阵列 CGH 和表达谱对大量人类 GBM 进行了肿瘤基因组分析，以便更全面地了解 GBM 发育的遗传事件。在表征 19q 染色体增益区域的过程中，我们将 Bcl2L12（Bcl2-Like-12）确定为一种神经胶质瘤癌基因，该基因在几乎所有 GBM 样本中都过度表达，但在低度疾病和正常样本中表达较低或不存在。组织。广泛的生化研究已证实，Bcl2L12 通过抑制线粒体后 caspase-3 和 caspase-7 激活，在原代星形胶质细胞培养物中发挥抗凋亡蛋白的作用。由于已知在线粒体后水平抑制细胞凋亡可阻止细胞凋亡但促进坏死，因此 GBM 中的 Bcl2L12 过度表达可能为该疾病生物学中的主要悖论（细胞凋亡抵抗但华丽坏死）提供合理的解释，并指出Bcl2L12 上调是恶性神经胶质瘤的关键进展事件。除了其胞质 caspase-3/7 抑制活性外，Bcl2L12 还存在于核质中，与 p53 相互作用并阻断 p53 介导的反式激活。为了更详细地分析基于细胞培养的检测中 Bcl2L12 调节的通路，并在体内对这些发现进行基因验证，本拨款提案旨在通过详细的结构功能分析进一步阐明 Bcl2L12 致癌活性的分子基础。我们将采用基于细胞培养的测定和原位 SCID 外植体肿瘤模型，使用基因工程神经元干细胞和成熟皮质星形胶质细胞来剖析细胞凋亡和 p53 调节活性。此外，我们将通过对 p53 介导的转录调控的详细研究，深入描述 p53 抑制的分子机制，该机制定义了 Bcl2L12 的另一种致癌活性。最后，将使用条件性 Bcl2L12 敲除小鼠评估 Bcl2L12 失活对 GBM 发展的影响，该小鼠可作为体内平台，评估 Bcl2L12 药理失活对恶性神经胶质瘤治疗的影响。治疗高级别神经胶质瘤的持续缺乏成功促使人们重新评估神经胶质瘤药物开发的各个方面。该拨款提案旨在通过完善对疾病的分子理解并开发更准确的体外和体内神经胶质瘤模型系统，专门解决目前在开发有效神经胶质瘤疗法方面未满足的需求。