Pathogenic Roles of SHP2 & PTPRD Tyrosine Phosphatases in High-Risk Neuroblastoma

描述(申请人提供)：神经母细胞瘤是一种发生在周围交感神经系统的高度恶性肿瘤，约占所有儿童癌症相关死亡的10%。最近对高危神经母细胞瘤的基因组重测序发现了三种主要类型的突变：激活ALK酪氨酸激酶的突变(8-10%)，激活SHP2磷酸酶的突变(2-3%)，以及涉及PTPRD基因的微缺失(6-10%)。我最近证明，激活的ALK与MYCN协同作用，通过抑制发育定时的凋亡反应，诱导斑马鱼神经母细胞瘤(朱等人，癌细胞)。我现在发现，激活的SHP2或Ptprd丢失也会加速MYCN诱导的神经母细胞瘤，但方式与激活的ALK不同。在我的密切合作伙伴、国际公认的磷酸酶生物学专家Ben Neel博士的建议下，我确定SHP2途径的多个组成部分在大多数人类神经母细胞瘤中高度过度表达，包括已知的癌基因和SHP2调节因子GAB2，以及ALK和NTRK1。这里要探讨的中心假设是SHP2和PTPRD是神经母细胞瘤发展的重要途径，值得进一步深入研究。我的主要目标是阐明这两条途径影响神经母细胞瘤启动和维持的潜在机制。我的具体目标是(1)确定突变激活的SHP2参与神经母细胞瘤的启动和维持的机制，并确定在缺乏SHP2突变的神经母细胞瘤中SHP2通路是否异常激活；以及(2)阐明PTPRD肿瘤抑制基因缺失在神经母细胞瘤的启动和维持中的作用机制。在这两个目标中，我将使用镶嵌和稳定的转基因方法以及结构-功能方法来揭示关键的下游通路和一个新的组织特异性的条件多西环素调控系统，以确定是否激活SHP2或失去PTPRD是肿瘤细胞持续生存所必需的，从而被认为是神经母细胞瘤发病的“驱动因素”。朱世珍(Jane)博士是达纳-法伯癌症研究所(DFCI)儿科肿瘤科的讲师，在斑马鱼癌症生物学领域的先驱A.Thomas Look博士的指导下工作。基于朱博士在中国和新加坡接受的医学和科学培训，她现在正在确定SHP2和PTPRD酪氨酸磷酸酶通路在神经母细胞瘤发病机制中的作用。Look博士久经考验的指导，再加上DFCI及其附属机构的研究社区提供的严谨和培养的科学环境，为朱博士在担任讲师期间以及在她过渡到独立研究人员的过渡期间取得成功提供了最大的机会。

DESCRIPTION (provided by applicant): Neuroblastoma, a highly malignant tumor that arises in the peripheral sympathetic nervous system, accounts for ~10% of all cancer-related deaths in children. Recent genomic resequencing of high-risk neuroblastoma has uncovered three main classes of mutations: those activating the ALK tyrosine kinase (8- 10% of cases), those activating the SHP2 phosphatase (2-3%), and microdeletions involving the PTPRD locus (6-10%). I recently demonstrated that activated ALK synergizes with MYCN to induce neuroblastoma in zebrafish by inhibiting a developmentally-timed apoptotic response (Zhu et al, Cancer Cell). I have now discovered that activated SHP2 or Ptprd loss also accelerates MYCN-induced neuroblastoma, but in a different way than does activated ALK. On the advice of my close collaborator, Dr. Ben Neel, an internationally recognized expert on phosphatase biology, I have determined that multiple components of the SHP2 pathway are highly overexpressed in most human neuroblastomas, including GAB2, a known oncogene and SHP2 regulator, as well as ALK and NTRK1. The central hypothesis to be explored here is that SHP2 and PTPRD represent vital pathways to the development of neuroblastoma and warrant further intensive investigation. My key objective is to elucidate the underlying mechanisms by which these two pathways influence neuroblastoma initiation and maintenance. My specific aims are (1) to define the mechanisms by which mutationally activated SHP2 contributes to neuroblastoma initiation and maintenance, and determine whether the SHP2 pathway is aberrantly activated in neuroblastoma cases that lack SHP2 mutations; and (2) to elucidate the mechanisms by which loss of the PTPRD tumor suppressor gene contributes to neuroblastoma initiation and maintenance. In these two Aims, I will use mosaic and stable transgenic as well as structure- function approaches to implicate key downstream pathways and a novel tissue-specific, conditional doxycycline-regulated system to establish whether activated SHP2 or loss of PTPRD is continuously required for tumor cell survival, thus qualifying as "drivers" of neuroblastoma pathogenesis. Dr. Shizhen (Jane) Zhu is an instructor in the Department of Pediatric Oncology at the Dana-Farber Cancer Institute (DFCI) working under the mentorship of Dr. A. Thomas Look, a pioneer in the field of zebrafish cancer biology. Building on Dr. Zhu's medical and scientific training in China and Singapore, she is now defining the roles of aberrant SHP2 and PTPRD tyrosine phosphatase pathways in the neuroblastoma pathogenesis. Dr. Look's proven mentorship coupled with the rigorous and nurturing scientific environment offered by the research community at DFCI and affiliated institutions offer the maximal opportunity for Dr. Zhu's success during her award period as an instructor and in her transition to become an independent investigator.