Modifiers of Tumor Susceptibility in Murine Neuroblastoma

神经母细胞瘤是一种起源于周围神经嵴的肿瘤，是儿童常见的致命性肿瘤。 转录因子MYCN的扩增在该肿瘤中频繁发生，并与晚期肿瘤相关。 疾病我们通过指导一种基因的表达，建立了高危神经母细胞瘤的转基因小鼠模型。 MYCN转基因到外周神经嵴，在酪氨酸羟化酶（TH）启动子的控制下。 遗传分析确定了人类和小鼠肿瘤之间的保守遗传变化，并认为， TH-MYCN转基因小鼠代表了儿童神经母细胞瘤的重要遗传模型。我们 我假设，导致神经母细胞瘤的其他遗传和表观遗传病变 在小鼠中的形成将在与儿童神经母细胞瘤相关的基因中。的长期目标 本申请是鉴定鼠和人神经母细胞瘤中的遗传和表观遗传变化。基因 这项研究中发现的可能揭示了与人类MYCN扩增相关的新机制和途径。 神经母细胞瘤，最终导致新的治疗靶点。 不同品系的小鼠对肿瘤的易感性不同。FVB/N品系中TH-MYCN转基因小鼠不发育 129/SvJ系中几乎所有转基因小鼠在4月龄时死于肿瘤，129/SvJ系FVB/NF 1系中几乎所有转基因小鼠在4月龄时死于肿瘤。 小鼠表现出4%的迁移率。这些观察结果表明，生殖系的结构或表观遗传变化 修饰基因在菌株之间不同，与Mycn相互作用，并成为易感性差异的基础 菌株之间。这些菌株特异性差异为鉴定次级遗传和 在鼠和人神经母细胞瘤中重要的表观遗传事件。 我们建议动员一个强大的插入诱变剂，脊椎动物睡美人（SB） 转座子，并将体细胞插入诱变与比较基因组学结合使用联合收割机 杂交和修饰遗传学鉴定影响小鼠肿瘤易感性基因 神经母细胞瘤目的1使用基于SB转座子的插入突变来加速致癌基因 突变和增加F1小鼠肿瘤的转移率。Aim 2应用基于数组的比较 基因组杂交，以表征自发和 转座子诱导的F1小鼠肿瘤，以表征菌株特异性甲基化模式，并 识别肿瘤的表观遗传变化。目的3在体外验证和表征候选基因 以及在体内，基于人类中特定候选基因的参与进行优先排序， 神经母细胞瘤

Neuroblastoma, a tumor of peripheral neural crest origin, is a common and lethal tumor of childhood. Amplification of the transcription factor MYCN occurs frequently in this tumor, and correlates with advanced disease. We generated a transgenic mouse model for high-risk neuroblastoma by directing expression of a MYCN transgene to the peripheral neural crest, under control of the Tyrosine Hydroxylase (TH) promoter. Genetic analyses identified conserved genetic changes between human and murine tumors, and argue that mice transgenic for TH-MYCN represent an important genetic model for childhood neuroblastoma. We hypothesize that the additional genetic and epigenetic lesions which contribute to neuroblastoma formation in the mouse will be in genes relevant to neuroblastoma in children. The long term objective of this application is to identify genetic and epigenetic changes in murine and human neuroblastoma. Genes identified in this study may reveal novel mechanisms and pathways relevant to human MYCN-amplified neuroblastoma, ultimately leading to novel therapeutic targets. Strains of mice differ in susceptibility to tumors. Mice transgenic for TH-MYCN in strain FVB/N do not develop tumors, nearly all transgenic mice in strain 129/SvJ die of tumors by 4 months of age, and 129/SvJ FVB/N F1 mice show 4% penetrance. These observations suggest that structural or epigenetic changes in germ line modifier genes differ between strains, interact with Mycn, and underlie the differences in susceptibility between strains. These strain-specific differences provide a critical resource to identify secondary genetic and epigenetic events important in both murine and human neuroblastoma. We propose to mobilize a powerful insertional mutagen, the vertebrate Sleeping Beauty (SB) transposon, and to combine use of somatic insertional mutagenesis with comparative genomic hybridization and modifier genetics to identify genes that influence susceptibility to tumors in murine neuroblastoma. Aim 1 uses SB transposon-based insertional mutagenesis to accelerate oncogenic mutations and to increase penetrance of tumors in F1 mice. Aim 2 applies array-based comparative genomic hybridization to characterize copy-number abnormalities in both spontaneous and transposon-induced tumors in F1 mice, to characterize strain-specific methylation patterns, and to identify epigenetic changes in tumors. Aim 3 validates and characterizes candidate genes in-vitro and in-vivo, prioritizing based on the involvement of specific candidate genes in human neuroblastoma.