Zebrafish PSNS Development and Neuroblastoma

描述（由申请人提供）：本指导临床科学家发展奖（K08）旨在通过神经发育生物学的培训，增强其在神经母细胞瘤研究方面的分子和临床背景，使候选人成为一名独立的内科科学家。该应用程序的目的是利用斑马鱼模型系统的遗传和胚胎优势，分离神经母细胞瘤中可能作为肿瘤抑制因子的基因。神经母细胞瘤是一种交感神经系统（SNS）的神秘肿瘤，其在婴儿中自发消退，在较大的儿童中不断发展，给治疗师和实验肿瘤学家带来了令人生畏的问题。尽管在过去的二十年中治疗方法有了很大的改进，但晚期疾病患者的长期治愈率仍然远远不能令人满意。本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抑制基因的功能丧失引起的。鉴定和描述它们调节的遗传程序将对正常SNS发育和NB中失调的分子途径产生重要的见解。申请人分离出两个SNS突变；CC1，定义为宫颈复合体中缺乏表达酪氨酸羟化酶（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基因的一个点突变。发育中的斑马鱼胚胎的SNS中CC2突变的表型后果将在Aim 1中确定，而负责CC2突变表型的基因将在Aim 2中确定。在Aim 3中，诱变筛选将扩大以识别更多的突变体，并将选择两个与神经发育专门相关的突变体进行进一步研究。A. Thomas Look博士是候选人的导师，他在NB研究方面有着堪称典范的记录，并在达纳-法伯癌症研究所投入了大量资源，用于斑马鱼模型中人类外周SNS发育和神经母细胞瘤病理生物学的研究。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咨询。在神经科学和发育神经生物学的教学课程将补充这一培训计划。这个K08提案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训练，使候选人能够测试上述假设，并在此过程中，使她能够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，她将以此作为修饰剂筛选的起点，以识别SNS发育中特定缺陷的遗传抑制因子。对这些修饰基因编码的蛋白质的深入了解可能会导致发现一些基因，这些基因可以作为治疗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.