Ras-mediated erbB signaling in Osteosarcoma

描述(申请人提供)：项目摘要：我们建议研究骨肉瘤中erb B家族信号转导的机制，确定RAS在该信号级联中的作用，并评估抑制erb B和/或RAS对骨肉瘤的治疗潜力，作为发展我的科学事业的一种手段。我是德克萨斯大学MD安德森癌症中心的儿科学助理教授，在基础免疫学和免疫疗法方面的实验室科学研究方面有很强的背景，但我最近才开始研究肿瘤生物学和细胞信号。我们已经确定了erb B家族成员(EGFR、HER-2和HER-4)在骨肉瘤细胞中的表达，并表明这些蛋白在骨肉瘤中被结构性磷酸化或激活。在这里，我们建议利用一种新的技术-组织裂解蛋白阵列-在骨肉瘤中快速筛选可能位于erb B和ras下游的一整套第二信使蛋白，在有构成的erb B信号存在的情况下，以及在erb B和/或ras被抑制的情况下。然后，我们将使用西方印迹和RNAi方法进行更详细的分析，以确认这第二个信使的角色。通过这些研究，我们将确定哪些第二信使在骨肉瘤中提供必要的生存和生长信号，并确定潜在的治疗靶点。最后，我们将使用特征良好的LM7骨肉瘤异种移植模型，评估使用小分子抑制剂阻断erB或RAS信号通路治疗骨肉瘤的可能性。在从事这些研究的过程中，我将熟练掌握信号转导领域的实验技术和知识，使我能够将这些方法应用于肉瘤研究领域，同时借鉴我以前的经验优势。我计划作为一名内科科学家的职业生涯，将我的大部分时间花在基于实验室的转化性研究上，以寻找有前景的肉瘤新疗法，同时在临床工作中投入有限的努力(20%或更少)，专注于肉瘤儿童的护理，特别是骨肿瘤。这个奖项与M.D.安德森癌症中心的支持和环境相结合，将为我提供理想的工具来建立我的职业生涯，并帮助我成为一名成功的实验室研究员，在国家来源的资金方面具有竞争力。 研究背景：骨肉瘤是青少年第三大常见癌症，也是最常见的骨恶性肿瘤。目前，30%到40%的骨肉瘤患者尽管进行了积极的化疗和手术，但仍有30%到40%的人死于骨肉瘤，这引起了人们对识别具有预后和治疗意义的标志物的极大兴趣。这项拟议的研究将确定来自erbB和下游蛋白靶点的小分子信号转导抑制剂在治疗骨肉瘤中的潜在作用，这也将作为确定儿童其他实体肿瘤这种作用的模型系统。

DESCRIPTION (provided by applicant): Project Summary: Here we propose examining the mechanisms of erbB family signaling in osteosarcoma, defining the role of Ras within this signaling cascade and assessing the therapeutic potential for osteosarcoma of inhibiting erbB and/or Ras, as a means of developing my scientific career. I am an Assistant Professor of Pediatrics at the University of Texas MD Anderson Cancer Center, with a strong background in laboratory-based scientific investigation from prior experiences with basic immunology and immunotherapy, but I began investigating tumor biology and cell signaling only recently. We have defined the expression of the erbB family members (EGFR, Her-2 and Her-4) in osteosarcoma cells, and showed that these proteins are constitutively phosphorylated, or activated, in osteosarcoma. Here we propose exploiting a new technology - tissue lysate protein arrays - to screen rapidly the entire set of second messenger proteins that may lie downstream of erbB and Ras in osteosarcoma, in the presence of constitutive erbB signaling and during inhibition of erbB, Ras or both. We will then pursue more detailed analyses, using western blot and RNAi approaches, to confirm the roles identified for these second messengers. With these studies we will determine which second messengers provide essential survival and growth signals in osteosarcoma, identifying potential targets for therapy. Finally, we will assess the possibility for osteosarcoma treatment of using small molecule inhibitors to block signaling from erbB or Ras, using the well-characterized LM7 osteosarcoma xenograft model. In pursuing these investigations, I will become adept in the experimental techniques and body of knowledge particular to the field of signal transduction, enabling me to apply these approaches to the field of sarcoma research while drawing on the strengths of my prior experience. I plan a career as a physician-scientist, spending the majority of my time in translational laboratory-based investigations of promising new treatments for sarcomas, combined with a limited (20% or less) effort in clinical work, focusing on the care of children with sarcomas, especially boney tumors. This award, in combination with the support and environment of M.D. Anderson Cancer Center, will provide the ideal vehicle for establishing my career and aiding me in becoming a successful laboratory investigator who is competitive for funding from national sources. Relevance: Osteosarcoma is the third most common cancer in adolescents and the most common malignancy of bone. Currently 30 to 40 percent of osteosarcoma patients die from their disease despite aggressive chemotherapy and surgery, which has generated tremendous interest in identifying markers of prognostic and therapeutic significance. The proposed studies will define the potential role of small molecule inhibitors of signal transduction, from erbB and from downstream protein targets, in treating osteosarcoma, which will also serve as the model system for determining this role in other solid tumors of childhood.