GENETIC PATHWAYS TOWARD GLIOMAGENESIS

描述(申请人描述)：新生胶质母细胞瘤患者 在目前的治疗下，Multiforme的中位生存期为9个月 可用的治疗方法。尽管低级别星形细胞瘤的预后是 明显更好，在至少50%的病例中，这些肿瘤将 中级(间变性)星形细胞瘤的进展 多形性胶质母细胞瘤。骨质疏松症发病机制的研究进展 这些致命的脑瘤由于缺乏真正的动物而受到阻碍。 该模型概括了这种疾病的遗传学和生物学。细胞遗传学 对临床胶质瘤标本的分析发现了多个遗传性病变 已知参与致癌/肿瘤抑制通路。 申请者的工作假设是不同的遗传途径 管理两种临床亚型胶质母细胞瘤的发展。那些 从低级别或中等级别的星形细胞瘤发展而来的累积突变 随着时间的推移，参与生长、分化、凋亡和 血管生成，产生逐渐更具侵略性的表型。相比之下， 新生胶质母细胞瘤的产生是由于 突变的初始表型是最高级别的肿瘤。这个 DePinho实验室已经改造出并广泛表征了 有几个基因缺失的小鼠可能参与了 这些不同的疾病实体的发病机制。这些产品的可用性 结合实验室在转基因和基因敲除方面的专业知识的小鼠 技术，为申请人提供了一个独特的机会来探索 胶质瘤发生的遗传机制，建立自发性脑胶质瘤小鼠模型 胶质母细胞瘤，并在这些领域获得概念和技术经验。 目的1：建立表达荧光标记的转基因小鼠 中间丝，GFAP和Nestin，可用作 在所有实验中，分别是星形胶质细胞和干细胞。目标2：评估 癌基因EGFR过表达在卵巢癌发病机制中的作用 胶质母细胞瘤。目的3：研究KEY基因已知突变的生物学效应 肿瘤抑制分子调控肿瘤生长、分化和生存的途径 以及这些突变如何与激活的EGFR在功能上相互作用。 目的4：确定与已知癌基因和肿瘤协同作用的基因 抑制子在恶性胶质瘤发生和/或进展中的作用 久负盛名的逆转录病毒植入方法。

DESCRIPTION (Applicant's Description): Patients with de novo glioblastoma multiforme have a median survival of nine months when treated with currently available therapy. Although the prognosis for low-grade astrocytomas is significantly better, in at least 50 percent of cases, these tumors will progress to intermediate-grade (anaplastic) astrocytomas and finally to glioblastoma multiforme. Progress in the understanding of the pathogenesis of these deadly brain tumors has been hampered by the lack of a bonafide animal model that recapitulates the genetics and biology of this disease. Cytogenetic analysis of clinical glioma specimens has identified multiple genetic lesions known to be involved in oncogenic/tumor suppressor pathways. The working hypothesis of the applicant is that distinct genetic pathways govern the development of the two clinical subtypes of glioblastoma. Those that develop from low- or intermediate-grade astrocytomas accumulate mutations over time in key pathways involved in growth, differentiation, apoptosis and angiogenesis, producing progressively more aggressive phenotypes. In contrast, de novo glioblastomas arise as a consequence of a critical combination of mutations in which the initial phenotype is the highest grade tumor. The DePinho laboratory has engineered and extensively characterized strains of mice with deletions of several of the genes which likely participate in the pathogenesis of these distinct disease entities. The availability of these mice coupled with the laboratory's expertise in transgenic and knockout technology, provides the applicant with a unique opportunity to probe the genetic mechanisms of gliomagenesis, develop a spontaneous mouse model of glioblastoma, and gain conceptual and technical experience in these areas. Aim 1: To generate a transgenic mouse that expresses fluorescently-labeled intermediate filaments, GFAP and nestin, to be used as specific markers of astrocytes and stem cells, respectively, in all experiments. Aim 2: To assess the role of overexpression of the oncogene, EGFR, in the pathogenesis of glioblastoma. Aim 3: To study the biological effects of known mutations in key tumor suppressor pathways governing growth, differentiation and survival of glial cells and how such mutations functionally interact with activated EGFR. Aim 4: To identify genes that cooperate with known oncogenes and tumor suppressors in the development and/or progression of malignant gliomas using a well-established retroviral insertional approach.