Regulation of the N-myc oncogene in neuroblastoma

神经母细胞瘤中 N-myc 癌基因的调控

• 批准号: 6689534
• 负责人: RANDAL K WADA
• 金额: $ 22.66万
• 依托单位: UNIVERSITY OF HAWAII AT MANOA
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6689534
• 关键词: DNA footprinting; clinical research; crosslink; gel mobility shift assay; gene induction /repression; gene mutation; genetic promoter element; human tissue; neoplasm /cancer chemotherapy; neoplasm /cancer genetics; neoplasm /cancer pharmacology; neuroblastoma; oncogenes; retinoate; tissue /cell culture; transcription factor; transfection

DESCRIPTION: (provided by applicant) The goal of this proposal is to identify the mechanism of N-myc transcriptional downregulation in neuroblastoma cells by retinoic acid (RA). RA exerts its transcriptional effects on N-myc through a roughly defined region of the promoter (RA response region, or RARR). These studies will test the hypothesis that RARR mutations in N-myc expressing cells leads to alteration of the complement or configuration of transcription factors that bind to the promoter, resulting in the inability to downregulate N-myc after RA treatment, the phenotypic resistance of cells to RA-induced differentiation, and the lack of clinical response to RA. In the first specific aim, transient transfections and DNA gel shift, cross linking, and footprinting analyses will be used to identify and characterize the promoter sequences and DNA binding proteins necessary for basal N-myc transcription, its downregulation by RA, and its constitutive expression in RA resistant cells. In the second specific aim, the biological effects of mutations that block the RA induced downregulation of the promoter will be tested using stable transfectants containing N-myc driven by either wild type or mutated promoters. The third specific aim will determine the clinical significance of RARR mutations by comparing their incidence in RA sensitive and resistant cell lines, in tumor pairs obtained at diagnosis and after relapse post-RA therapy, and in high and low risk tumors. The presence of RARR mutations at diagnosis will also be correlated with decreased survival in a population of high-risk neuroblastoma patients treated with RA. RA is currently the only effective biologic modifier for the therapy of neuroblastoma patients with minimal residual disease. Results obtained from these investigations will provide a molecular-based, mechanistic foundation that will allow eventual prognostication of patients with respect to treatment with RA. Such data will aid in identifying RA-resistant patient candidates for trials of other biologically active agents. Ultimately, an understanding of oncogene regulation will facilitate the future rational development of combination differentiation therapy of neuroblastoma, which might be effective even in the induction setting against bulky disease.

描述：（由申请人提供）该提案的目标是确定 神经母细胞瘤细胞中 N-myc 转录下调的机制 视黄酸（RA）。 RA 通过 N-myc 发挥其转录作用 粗略定义的启动子区域（RA 响应区域，或 RARR）。这些 研究将检验 N-myc 表达细胞中 RARR 突变的假设 导致转录因子的补体或构型改变 与启动子结合，导致无法下调 N-myc RA治疗后，细胞对RA诱导的表型抗性 分化，以及缺乏对 RA 的临床反应。在第一个具体 目标、瞬时转染和 DNA 凝胶位移、交联和足迹 分析将用于识别和表征启动子序列 基础 N-myc 转录所需的 DNA 结合蛋白，其 RA 的下调及其在 RA 耐药细胞中的组成型表达。在 第二个具体目标，阻断 RA 的突变的生物学效应 诱导的启动子下调将使用稳定的测试 含有由野生型或突变启动子驱动的 N-myc 的转染子。 第三个具体目标将确定 RARR 的临床意义 通过比较 RA 敏感和耐药细胞中的突变发生率 在诊断时和 RA 治疗后复发后获得的肿瘤对中， 以及高风险和低风险肿瘤。诊断时存在 RARR 突变 也与高风险人群的生存率下降有关 接受 RA 治疗的神经母细胞瘤患者。 RA是目前唯一有效的 生物修饰剂用于治疗神经母细胞瘤患者 残留病。从这些调查中获得的结果将提供 基于分子的机械基础将允许最终 RA 治疗患者的预后。此类数据将 帮助确定 RA 耐药患者候选者以进行其他试验 生物活性剂。最终，了解癌基因调控 将有利于未来组合差异化的合理发展 神经母细胞瘤的治疗，即使在诱导过程中也可能有效 对抗大面积疾病。

项目成果

Inhibition of N-myc expression and induction of apoptosis by iron chelation in human neuroblastoma cells.

• 发表时间: 2001-02
• 期刊: Cancer research
• 影响因子: 11.2
• 作者: L. Fan;J. Iyer;S. Zhu;K. Frick;Randal K. Wada;A. Eskenazi;P. Berg;N. Ikegaki;R. Kennett;C. Frantz