The Role of MCM7 in Neuroblastoma Tumorigenesis

MCM7 在神经母细胞瘤肿瘤发生中的作用

• 批准号: 6919226
• 负责人: JASON M SHOHET
• 金额: $ 13.4万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6919226
• 关键词: DNA binding protein; DNA replication; carcinogenesis; flow cytometry; fluorescent in situ hybridization; gene expression; gene expression profiling; genetic transcription; genetically modified animals; histology; immunocytochemistry; laboratory mouse; neoplasm /cancer genetics; neuroblastoma; oncogenes; pediatric neoplasm /cancer; plasminogen activator; polymerase chain reaction; protein protein interaction; protein structure function; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Neuroblastoma is the most common extra-cranial solid tumor in children, accounting for 15% of all pediatric cancer deaths despite modern dose-intensive chemotherapy. Improvements in therapy will come from a deeper understanding of the biology of this cancer. Clinical and biological risk stratification identifies the MYCN oncogene as the sole reliable marker for high-risk disease. MYCN is amplified in 25-35% of cases and distinguishes a subset of patients with highly aggressive disease and poor prognosis. The MYCN protein is a bHLH leucine zipper nuclear protein that forms heterodimers with the MAX protein and binds to DNA acting as both a transcriptional activator and repressor. However, direct downstream targets of MYCN connecting its overexpression to the particularly malignant phenotype remain undefined. Using gene expression profiling and subtractive hybridization we have identified a series of MYCN regulated genes. One of these genes, MCM7 is the focus of this proposal. MCM7 is a direct transcriptional target of MYCN with essential functions regulation DNA replication in S-phase. This gene interacts with several important regulatory molecules including Rb and MAT1 kinase. We have shown that MCM7 expression closely correlates with MYCN amplification in vivo and that it alters gene transcription in a cell culture system. The central hypothesis of this proposal is that aberrant expression of MCM7 mediates at least some of the transformative and malignant consequences of MYCN oncogene amplification through alterations in DNA synthetic processes, induction of chromosomal instability, or secondary changes in gene transcription mediated by its interaction with other non-MCM proteins. The specific aims of this proposal will pursue this hypothesis and test whether MCM7 is a good target for novel therapeutic interventions as follows: Specific Aim I will test whether inhibition of MCM7 function will influence the growth and metastasis of neuroblastoma cell lines. Specific Aim II will characterize the mechanism and specificity of chromosomal instability induced by overexpression of MCM7. Specific Aim III will evaluate phenotypic changes and tumor incidence in transgenic mice with tissue specific constitutive overexpression of MCM7.

描述（由申请人提供）：神经母细胞瘤是儿童中最常见的颅外实体瘤，尽管采用现代剂量密集型化疗，仍占所有儿童癌症死亡的 15%。 治疗的改进将来自对这种癌症生物学的更深入的了解。 临床和生物学风险分层将 MYCN 癌基因确定为高风险疾病的唯一可靠标记。 MYCN 在 25-35% 的病例中扩增，并区分出患有高度侵袭性疾病和预后不良的一部分患者。 MYCN 蛋白是一种 bHLH 亮氨酸拉链核蛋白，与 MAX 蛋白形成异二聚体，并与 DNA 结合，充当转录激活子和阻遏子。 然而，将其过度表达与特别恶性表型联系起来的 MYCN 直接下游靶点仍不清楚。 使用基因表达谱和消减杂交，我们鉴定了一系列 MYCN 调控基因。 MCM7 是这些基因之一，是本提案的重点。 MCM7 是 MYCN 的直接转录靶标，具有调节 S 期 DNA 复制的基本功能。 该基因与几种重要的调节分子相互作用，包括 Rb 和 MAT1 激酶。 我们已经证明 MCM7 表达与体内 MYCN 扩增密切相关，并且它改变细胞培养系统中的基因转录。 该提议的中心假设是，MCM7 的异常表达至少通过 DNA 合成过程的改变、染色体不稳定性的诱导或由其与其他非 MCM 蛋白相互作用介导的基因转录的二次变化介导 MYCN 癌基因扩增的一些转化和恶性后果。 该提案的具体目标将追求这一假设并测试 MCM7 是否是新型治疗干预的良好靶点，具体目标如下： 具体目标 I 将测试 MCM7 功能的抑制是否会影响神经母细胞瘤细胞系的生长和转移。 具体目标 II 将表征 MCM7 过度表达引起的染色体不稳定的机制和特异性。 Specific Aim III 将评估组织特异性 MCM7 组成型过表达的转基因小鼠的表型变化和肿瘤发生率。