Role of MYCN inhibition in NBL Tumor Progression

MYCN 抑制在 NBL 肿瘤进展中的作用

基本信息

批准号：
7405342
负责人：
LOUIS CHESLER
金额：
$ 6.2万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-04-01 至 2010-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7405342
关键词：
1-Phosphatidylinositol 3-Kinase Ablation Accounting Address Advisory Committees Animals Antibodies Antisense RNA Apoptosis Attention Automobile Driving Cell Cycle Cell Line Cell Proliferation Cell physiology Cells Cessation of life Child Childhood Clinical Congresses Development Disease regression Down-Regulation Doxycycline Failure Gene Mutation Goals Growth Human Image In Vitro Inhibition of Apoptosis Laws Lead Link Luciferases MYCN gene Malignant - descriptor Malignant Childhood Neoplasm Malignant Neoplasms Mediating Modeling Molecular Weight Mus National Cancer Institute Neuroblastoma Neurologic New Agents Oncogenes Outcome Pathway interactions Patients Pharmaceutical Preparations Pharmacologic Substance Phosphatidylinositide 3-Kinase Inhibitor Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide Phosphorylation Play Pre-Clinical Model Protein Overexpression Proteins RNA Interference Reagent Relapse Research Personnel Resistance Risk Role Solid Neoplasm System Testing Therapeutic Transgenic Model Transgenic Organisms Vascularization Work Xenograft Model Xenograft procedure c-myc Genes cell growth chemotherapy in vivo inhibitor/antagonist mouse model mutant neoplastic cell novel novel strategies pre-clinical prevent programs protein expression response transgene expression tumor tumor growth tumor progression

项目摘要

DESCRIPTION (provided by applicant): Neuroblastoma (NBL), a devastating neurologic solid tumor of children, accounts for 15% of yearly pediatric oncologic deaths. While most NBL patients are cured with multi-modal chemotherapy, 30% carry a genetic mutation -- MYCN oncogene amplification, which is tightly linked to therapeutic failure, tumor progression and relapse. The broad goal of this study is to assess the role of MYCN inhibition in preventing the progression of MYCN-amplified tumors in this high risk group of patients with few therapeutic choices. The study focuses in two specific aims on a novel role for the PI3-kinase pathway in stabilization of Mycn protein, and the efficacy of specific low-molecular weight pathway inhibitors for preventing NBL cell proliferation and tumor progression. The significance of the work is in the potential identification of a practical new approach to therapy of high-risk patients, and in the development of a new NBL transgenic mouse model ideal for the pre-clinical testing of new agents as they are developed by others in the field. In aim I, the role of the PI3-kinase pathway in regulating Mycn protein expression is mechanistically studied in vitro using established MYCN-amplified and unamplified cell lines. Specific attention is focused on Mycn protein phosphorylation, using two unique reagents: an antibody to phospho-Mycn and phospho-Mycn point mutants. The effects of Mycn inhibition on cell cycling, proliferation, apoptosis and differentiation. The effects of pathway inhibitors are compared to that of specific MYCN ablation by RNAi. In aim II, the effects of pharmacologic Mycn suppression on NBL tumor growth is assessed in human xenografts, a native TH-MYCN transgenic mouse model of NBL, and a new TRE-MYCN-Luc model of NBL in which MYCN expression is regulable and tumors are detectable in vivo using Xenogen imaging. The effects of pathway inhibition are compared to that of regulated suppression of MYCN expression using doxycycline (Dox) in the TRE-MYCN-Luc model and in xenografts of SHEP-tet21 cells, which suppress MYCN expression in response to Dox.

描述（由申请人提供）：神经母细胞瘤（NBL）是一种毁灭性的儿童神经系统实体瘤，占年龄肿瘤学死亡的15％。虽然大多数NBL患者均使用多模式化疗治愈，但30％的患者携带遗传突变 - MyCN癌基因扩增，这与治疗衰竭，肿瘤进展和复发密切相关。这项研究的广泛目的是评估MYCN抑制在预防MYCN放大肿瘤进展中的作用，而治疗选择很少。该研究重点是两个特定的目的，是PI3-激酶途径在MYCN蛋白稳定中的新作用，以及特异性低分子重量途径抑制剂在防止NBL细胞增殖和肿瘤进展方面的疗效。这项工作的意义在于潜在地鉴定一种实用的高危患者治疗方法，以及开发新的NBL转基因小鼠模型，非常适合对新药物进行临床前测试的理想，因为它们是由该领域的其他人开发的。在AIM I中，使用已建立的MYCN扩增和未膨胀的细胞系在体外研究了PI3-激酶途径在调节MYCN蛋白表达中的作用。使用两种独特的试剂：一种磷酸化和磷酸化点突变体的抗体。 MYCN抑制对细胞循环，增殖，凋亡和分化的影响。将途径抑制剂的作用与RNAi特定的MYCN消融的作用进行了比较。在AIM II中，在人异种移植物，NBL的天然TH-MYCN转基因小鼠模型中评估了药理学MYCN抑制对NBL肿瘤生长的影响，并且NBL的新型TRE-MYCN-LUC模型在该模型中可调节MyCN表达，并且可以使用Xenogen Imaging在体内检测到肿瘤。将途径抑制的影响与在TRE-MYCN-LUC模型中使用强力霉素（DOX）和Shep-TET21细胞的异种移植物中使用强力霉素（DOX）进行了比较，从而抑制MYCN的表达，以响应DOX。