Zebrafish Peripheral Sympathetic Nervous System Development and Neuroblastoma

描述(申请人提供)：这个有指导的临床科学家发展奖(K08)旨在使候选人能够通过神经发育生物学的培训来增强她在神经母细胞瘤研究方面的分子和临床背景，从而成为一名独立的内科科学家。这项应用的目标是利用斑马鱼模型系统的遗传和胚胎优势，分离可在神经母细胞瘤中发挥肿瘤抑制作用的基因，神经母细胞瘤是交感神经系统(SNS)的一种神秘肿瘤，其婴儿的自发退化和较大儿童的无情进展给治疗师和实验肿瘤学家带来了令人望而生畏的问题。尽管在过去20年中对治疗方法进行了重大修改，但晚期疾病患者的长期治愈率仍然远远不能令人满意。这项研究的中心假设是，神经母细胞瘤的发展是由调节SNS正常胚胎发育的几种类型的抑制基因的功能丧失启动的。识别和描述它们调控的遗传程序将对SNS的正常发育和NB中变得不受调控的分子途径产生重要的见解。申请人已经分离出两个SNS突变；CC1，定义为宫颈复合体中没有表达酪氨酸羟化酶(TH)的细胞；CC2，与相同结构中表达TH的细胞数量增加有关。CC1突变已被鉴定为FoxD3基因点突变。CC2突变在斑马鱼胚胎发育中的SNs中的表型后果将在目标1中确定，而负责CC2突变表型的基因将在目标2中确定。在目标3中，将扩大突变筛选以鉴定更多的突变，并将选择两个与神经发育有关的突变进行进一步研究。候选人的导师A.Thomas Look博士在NB研究方面有着堪称典范的记录，并在Dana-Farber癌症研究所投入大量资源，在斑马鱼模型中研究人类外周SNS发育和神经母细胞瘤病理生物学。此外，一个由备受尊敬的医学科学家组成的咨询委员会将提供科学和职业建议。神经科学和发育神经生物学的教学课程工作将补充这一培训计划。这项K08建议的目标是获得必要的发育神经生物学和斑马鱼模型的科学培训，使候选人能够检验上述假设，并通过这样做，让她发展成为一名成功和独立的内科科学家。她的职业发展规划、世界一流的培训环境以及她所在部门的承诺将使这一目标得以实现。此外，这些目标的成功完成将为她建立神经母细胞瘤斑马鱼模型的长期目标提供基础，她将以此为起点进行修饰筛选，以确定SNS发育中特定缺陷的基因抑制因子。对这种修饰基因编码的蛋白质的洞察可能会导致发现一些基因，这些基因可能会成为治疗患有晚期疾病的大龄儿童的新药物靶点。

DESCRIPTION (provided by applicant): This Mentored Clinical Scientist Development Award (K08) is designed to enable the candidate to become an independent physician-scientist, by augmenting her molecular and clinical background in neuroblastoma research, with training in neurodevelopmental biology. The goal of this application is to use the genetic and embryonic advantages of the zebrafish model system to isolate genes that could function as tumor suppressors in neuroblastoma, an enigmatic tumor of the sympathetic nervous system (SNS) whose spontaneous regression in infants and relentless progression in older children pose daunting problems to therapists and experimental oncologists alike. Despite major modifications of therapy over the past two decades, the long-term cure rate in patients with advanced disease is still far from satisfactory. The central hypothesis of this research is that neuroblastoma development is initiated by the loss of function of several types of suppressor genes that regulate normal embryologic development of the SNS. The identification and delineation of the genetic programs they regulate will yield important insights into normal SNS development and the molecular pathways that become dysregulated in NB. The applicant has isolated two SNS mutations; CC1, defined by the absence of tyrosine hydroxylase (TH) expressing cells in the cervical complex, and CC2, associated with increased numbers of TH expressing cells in the same structure. The CC1 mutation has been characterized and identified as a point mutation in the FoxD3 gene. The phenotypic consequences of the CC2 mutation in the SNS of developing zebrafish embryos will be determined in Aim 1, while the genes responsible for the CC2 mutant phenotype will be determined in Aim 2. In Aim 3, the mutagenesis screen will be expanded to identify more mutants and two that specifically relate to neural development will be picked for further study. Dr A. Thomas Look, the candidate's mentor, has an exemplary track record in NB research and has committed major resources at the Dana-Farber Cancer Institute to the study of human peripheral SNS development and neuroblastoma pathobiology in the zebrafish model. In addition, an advisory committee of highly regarded medical scientists will provide scientific and career advice. Didactic course work in neuroscience and developmental neurobiology will complement this training program. The goal of this K08 proposal is to obtain the necessary scientific training in developmental neurobiology and zebrafish models to allow the candidate to test the above hypothesis, and in doing so, to allow her to develop into a successful and independent physician scientist. Her career development plan, world-class training environment, and commitment from her Department will allow the realization of this goal. Furthermore, successful completion of these aims will provide a base for her long-term goal of establishing zebrafish models of neuroblastoma, which she will use as a starting point for modifier screens to identify genetic suppressors of particular defects in SNS development. Insight into the proteins encoded by such modifier genes may lead to the discovery of genes that could serve as novel drug targets for the treatment of older children with advanced disease.