Interplay between low levels of GAS7 expression and MYCN overexpression and its impact on neuroblastoma metastasis

GAS7低水平表达与MYCN过表达之间的相互作用及其对神经母细胞瘤转移的影响

基本信息

批准号：
10647655
负责人：
Shizhen Zhu
金额：
$ 35.64万
依托单位：
MAYO CLINIC ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-15 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10647655
关键词：
17p 17p13.1 Acceleration Accounting Adaptor Signaling Protein Adhesions Age Months Animal Model Attenuated Binding Biochemical Bioinformatics Biological Assay Biology Bone Marrow Cell membrane Cells Cephalic Cessation of life Childhood Chromosomes Clinical Complex Complication Coupled Data Data Set Development Diagnosis Disease Dissociation Distant Doxycycline Emerging Technologies Family Fishes Frequencies GAS7 gene Gene Expression Genes Genetic Transcription Genomics Goals Growth Hematogenous Heterozygote Human Immunoprecipitation Invaded Knock-out Knowledge Link Liver Loss of Heterozygosity Luciferases MYCN gene Malignant - descriptor Malignant Neoplasms Malignant neoplasm of lung Methylation Modeling Molecular Molecular Target Mus Mutation N-Myc Protein Neoplasm Metastasis Neuroblastoma Neuronal Differentiation Non-Malignant Ocular orbit Oncogenes Outcome Pathogenesis Patients Pediatric Neoplasm Positioning Attribute Primary Neoplasm Process Promoter Regions Reporter Role Sampling Signal Transduction Site Solid Neoplasm Subgroup System Testing Therapeutic Tissues Transplantation Treatment Failure Tumor stage Western Blotting Work Zebrafish age group bone cell motility chemotherapy effective therapy gene repression genome sequencing genomic locus high risk improved in vivo innovation insight loss of function lymph nodes member metastatic process migration mouse model neoplastic cell neuroblast novel novel therapeutics overexpression patient subsets promoter protein expression single-cell RNA sequencing success tool tumor whole genome

项目摘要

Neuroblastoma (NB), the most common extracranial solid tumor in children, typically presents at diagnosis with evidence of widespread metastasis, especially in patients with amplification of the MYCN oncogene. This subgroup has a very high risk of treatment failure and death despite receiving greatly intensified chemotherapy. Attempts to improve the treatment of disseminated NB have been impeded by the lack of a detailed understanding of the multistep cellular and molecular pathogenesis of this complex form of the tumor. Thus, new mechanistic insights leading to safer and more effective treatments for metastatic NB are urgently needed. This proposal grew from whole-genome sequencing analyses of primary NB samples from 135 patients, in which we identified a novel deletion of a growth arrest-specific gene 7 (GAS7, located on chromosome 17p13.1), in a subset of patients with high-risk NB defined by MYCN amplification. Further analysis showed that low levels of GAS7 expression are associated with advanced-stage, MYCN amplification and a poor clinical outcome, while knockout of gas7 in a zebrafish model of NB with MYCN overexpression promotes hematogenous metastasis of tumor cells to sites commonly seen in patients with this disease. We also found that MYCN can bind indirectly to the GAS7 promoter region, leading to its transcriptional repression, while reduced expression of GAS7 can increase MYCN protein levels. Hence, the central hypothesis of this application is that, in addition to cases with the heterozygous deletion of 17p, over- or amplified expression of MYCN can downregulate GAS7 expression and maintain at deficient levels of this adaptor protein. This, in turn, appears to maintain MYCN protein expression at high levels, facilitating dissociation of tumor cells from the primary tumor and their subsequent dissemination. This hypothesis will be tested in three specific aims: 1) To probe the interplay between MYCN overexpression and low levels of GAS7 expression in metastatic NB, 2) To dissect the MYCN-induced cascade of downstream transcriptional and signaling changes in the context of GAS7 deficiency that lead to metastasis in high-risk NB, and 3) To assess the contribution of GAS7 deficiency to the timing of NB dissemination and the ability of GAS7 overexpression to block or attenuate MYCN-driven tumor metastasis, and to evaluate in vivo the effect of MYCN overexpression-GAS7 deficiency on NB metastasis using different murine models. The major innovation of this proposal is the use of emerging technology with a forward-looking integration of host and tumor genomics in a high-throughput animal model to dissect the interplay between low levels of GAS7 expression and MYCN overexpression in NB metastasis. The significance of this study is threefold: it will (i) shed new light on the contributions of MYCN to early NB metastasis via its effects on adhesion, motility, and invasion, (ii) clarify the mechanism(s) that underlie MYCN’s cooperation with low levels of GAS7 expression in NB metastasis, and (iii) identify promising molecular targets within metastatic signaling cascades that could be exploited therapeutically.

神经母细胞瘤（NB）是儿童中最常见的颅外实体瘤，通常在诊断时出现宽度转移的证据，尤其是在霉菌癌基因扩增的患者中。这亚组的治疗失败风险很高，而死亡目的地则接受了大量强烈的化学疗法。缺乏细节阻碍了改善散布NB治疗的尝试理解这种肿瘤的复杂形式的多阶段细胞和分子发病机理。那，迫切需要新的机械见解，从而导致转移性NB的更安全，更有效的治疗方法。该提案是由135名患者的主要NB样品的全基因组测序分析中提出的，我们确定了生长特异性基因7的新颖缺失（GAS7，位于染色体上 17p13.1），在由MYCN扩增定义的高风险NB患者中。进一步的分析表明低水平的GAS7表达与晚期，MYCN扩增和较差有关临床结果，而在用MYCN过表达的NB斑马鱼模型中敲除GAS7的促进肿瘤细胞对这种疾病患者常见的部位的血源转移。我们还发现 MYCN可以间接与GAS7启动子区域结合，导致其转录表示，而降低的气体表达可以增加mycn蛋白水平。因此，这是这一点的中心假设应用是，除了17p的杂合缺失外， MYCN可以下调GAS7表达并保持该衔接蛋白水平不足。这又似乎可以在高水平上维持MYCN蛋白的表达，从而支持肿瘤细胞从原发性肿瘤及其随后的传播。该假设将以三个特定目的进行检验：1）探测MYCN过表达与转移性NB中气体表达低水平之间的相互作用，2）在下游转录和信号变化的背景下剖析MYCN诱导的级联导致高风险NB转移的GAS7缺乏，3）评估GAS7缺乏症的贡献到NB传播的时机以及GAS7过表达阻塞或衰减MYCN驱动的能力肿瘤转移，并在体内评估MYCN过表达GAS7缺乏对NB的影响转移使用不同的鼠模型。该提案的主要创新是使用新兴高通量动物模型中宿主和肿瘤基因组学的前瞻性整合的技术在NB转移中剖析低水平的气体表达和MYCN过表达之间的相互作用。这这项研究的意义是三倍：它将（i）对MYCN对早期NB的贡献进行新的启示转移通过其对广告，运动和入侵的影响，（ii）确定基于的机制 MYCN的合作与NB转移中的气体7表达较低，以及（iii）确定诺言可以热探索的转移信号传导级联体内的分子靶标。