Targeting Pten - An Upstream, Downstream and Offstream Approach

过去几年的遗传学研究已经确定，超过80%的湖南黑色素瘤携带B-Raf或N-Ras癌基因突变，这些癌基因控制MEK/MAPK信号通路。现在显而易见的是，针对该途径的组分开发的第二代和第三代抑制剂未能引起对黑素瘤肿瘤发展/进展的有效抑制，这突出了迫切需要鉴定在该肿瘤类型中失调的其他途径。在可能增加去调节的MEK/MAPK信号传导的主要途径中是Pten/Akt信号传导级联。在黑色素瘤中，30%的肿瘤具有失活的Pten，50%的肿瘤表达组成型活性Akt。该计划项目代表了一种高度综合的方法来翻译有关的基础科学发现， 黑色素瘤中的Pten/Akt信号通路该提议的总体假设是，理解Pten介导的黑色素瘤肿瘤发展和进展的机制为靶向其频繁失活的后果提供了独特的机会。为了实现这一目标，该计划 该项目联合了一组国际知名的合作者，他们将跨越学科界限，为Pten/Akt介导的黑色素瘤发展提供新的见解，并为Pten/Akt靶向肿瘤治疗开发新的策略。我们将首次定义泛素连接酶Siah的作用， 在黑色素瘤中上调，并且是其发展和转移所必需的，以及鉴定和表征与Pten/Akt途径相关的代谢通量。我们还提出了高度集中的努力，在验证新的药物靶点，基于结构的药物设计，并确定分子特征，以表明患者将响应Ren/Akt靶向治疗。 在三个核心的综合支持下，三个项目将共同解决Pten生物学中的以下核心问题。项目jl：确定Pten/Akt如何通过E3连接酶Siah 2调节肿瘤发生和转移。项目二：定义Pten/Akt调控的中心碳代谢方面，并评估这些代谢中心是否是Pten null中有效的药物靶点 肿瘤的项目3：利用基于结构的药物设计开发靶向AKT和Siah 2的新药。除管理核心（核心A）外，还将支持siRNA构建体和文库（核心B），以及分析人肿瘤细胞系和TMA，以获得在拟定研究过程中鉴定的标志物的分子特征，并分析针对在2D、3D培养物和动物模型中研究的每种组分开发的抑制剂（核心C）。 总体而言，这种分子生物学、生物化学、代谢组学和基于结构的药物设计的组合为解决以关键肿瘤抑制基因Pten/Akt为中心的肿瘤生物学中关键未回答的问题的综合研究提供了首屈一指的机会，重点是恶性黑色素瘤。

Genetic studies over the past few years have identified that over 80% of hunnan melanomas carry mutations in B-Raf or N-Ras oncogenes, which control the MEK/MAPK signaling pathway. It is now apparent that second and third generation inhibitors developed against components of this pathway fail to elicit effective inhibition of melanoma tumor development/progression, highlighting the urgent need to identify additional pathway(s) that are deregulated in this tumor type. Among primary pathways that are likely to augment deregulated MEK/MAPK signaling is the Pten/Akt signaling cascade. In melanoma, 30% of tumors have inactivated Pten and 50% of tumors express a constitutively active Akt. This program project represents a highly integrated approach to translate basic science findings pertaining to the Pten/Akt signaling pathway in melanoma. The overall hypothesis of this proposal is that understanding mechanisms underlying the Pten mediated melanoma tumor development and progression offers unique opportunities for targeting the consequence of its frequent inactivation. To achieve this goal, this Program Project unites an internationally renowned group of collaborators who will cross disciplinary boundaries to provide novel insights into Pten/Akt-mediated melanoma development and to develop new strategies for Pten/Akt-targeted tumor therapy. For the first time we will define the role of the ubiquitin ligase Siah which is upregulated in melanoma and is required for its development and metastasis, as well as identify and characterize metabolic fluxes that are linked to the Pten/Akt pathway. We also propose highly focused efforts in the validation of new drug targets, structure-based drug design, and the identification of molecular signatures to indicate patients that will respond to Ren/Akt-targeted therapy. With the integrated support of the three cores, the three projects will work together to address the following central questions in Pten biology. Project jl: Determine how Pten/Akt regulates tumorigenesis and metastasis through the E3 ligase Siah2. Project 2: Define aspects of central carbon metabolism that are regulated by Pten/Akt, and assess whether these metabolic hubs are valid drug targets in Pten null tumors. Project 3: Use structure-based drug design to develop novel drugs targeting AKT and Siah2. In addition to the administrative core (Core A), support will be provided for siRNA constructs and libraries (Core B), and analysis of human tumor cell lines and TMAs for molecular signatures of markers identified in the course of the proposed studies and for analysis of inhibitors developed against each of the components studied in 2D, 3D cultures and animal rriodel (Core C). Overall, this combination of molecular biology, biochemistry, metabolomics, and structure based drug design offers a second to none opportunity for integrated studies that address critical unanswered questions in tumor biology centered on key tumo[ suppressor gene Pten/Akt with focus on malignant melanoma.