Mitochondrial Hsp90s Regulation of Tumor Bioenergetics and Metastasis

描述(由申请人提供)：细胞应激感应通路有助于适应不利的肿瘤微环境条件(例如营养缺乏、酸中毒和缺氧)，并有助于获得新的恶性特性。在此背景下，Hsp90家族的分子伴侣是结节癌基因，控制客户蛋白的折叠和成熟，参与肿瘤细胞的增殖、生存和对应激的适应。Hsp90的线粒体库(MtHsp90)及其相关的伴侣蛋白TRAP-1在肿瘤细胞中拮抗线粒体通透性转换和维持能量产生。我们团队的最新证据表明，mtHsp90导向的生物能量学对于拮抗宏观自噬和调节细胞器未折叠蛋白反应(UPR)至关重要，UPR导致肿瘤细胞基因表达的深刻代偿性重塑。自从加入Altieri实验室以来，我发现用一种选择性地在线粒体中积聚的小分子抑制剂(Gamitrinib)靶向Hsp90的伴侣ATPase活性，抑制细胞运动激酶FAK和Src的激活，抑制细胞骨架动力学，并抑制肿瘤细胞的迁移和侵袭。我们假设线粒体Hsp90是肿瘤转移的新调节因子。在目前的应用中，我们将研究自噬和UPR在线粒体Hsp90调控肿瘤细胞骨架动力学和运动性中的作用，以及它们在体内转移扩散中的作用。在目标1中，我们建议阐明mtHsp90在代谢应激下调节FAK激活和肿瘤细胞运动中自噬起始复合体的分子需求。在目标2中，我们将研究UPR在mtHsp90介导的肿瘤细胞细胞骨架动力学调节中的作用。在目标3中，我们将验证mtHsp90在体内转移动物模型中的作用。我们的研究将验证线粒体Hsp90调控肿瘤生物能量学对转移疾病的重要性，长期目标是确定新的治疗靶点，以防止癌症的转移扩散。在这里提出的研究计划将拓宽我的知识，批判性思维和多个调查领域的整体背景培训 包括细胞生物学、生物化学、分子生物学和癌症生物学。我还将在研究细胞运动、UPR、肿瘤细胞侵袭和体内转移动物模型的广泛定量方法方面获得宝贵的专业知识。我对这一训练机制的目标是整合所有这些新知识，并形成对关键应激和代谢途径如何调节转移的全面理解。通过完成我的培训计划的其他部分，我希望在规划、实施和沟通我的研究成果方面变得非常胜任，培养进行研究的专业责任感，以及学习成为一名独立调查人员所必需的关键人际交往技能。总而言之，本申请将有助于我成功地成为一名负责任和富有成效的独立调查员。

DESCRIPTION (provided by applicant): Cellular stress sensing pathways contribute to adaptation to unfavorable tumor microenvironment conditions (e.g. nutrient deprivation, acidosis and hypoxia) and to the acquisition of new malignant properties. In this context, the molecular chaperones of the Hsp90 family are nodal cancer genes, controlling the folding and maturation of client proteins involved in tumor cell proliferation, survival and adaptation to stress. Mitochondrial pools of Hsp90 (mtHsp90) and its related chaperone, TRAP-1, antagonize mitochondrial permeability transition and maintain energy production in tumor cells. Recent evidences from our group indicate that mtHsp90s- directed bioenergetics is essential to antagonize macroautophagy and to regulate an organelle unfolded protein response (UPR) that leads to profound compensatory remodeling of gene expression in tumor cells. Since joining the Altieri laboratory, I found that targeting the chaperone ATPase activity of Hsp90s with a small molecule inhibitor selectively engineered to accumulate in mitochondria (Gamitrinib), suppressed activation of cell motility kinases FAK and Src, inhibited cytoskeletal dynamics and suppressed tumor cell migration and invasion. We hypothesize that mitochondrial Hsp90s are novel regulators of metastasis in tumors. In the present application we will investigate the role o autophagy and the UPR on mitochondrial Hsp90s regulation of tumor cell cytoskeletal dynamics and motility, and their contribution to metastatic dissemination in vivo. In Aim 1, we propose to elucidate the molecular requirements for mtHsp90s modulation of the autophagy initiating complex in FAK activation and tumor cell motility under metabolic stress. In Aim 2, we will study the involvement of the UPR in mtHsp90s-mediated regulation of cytoskeletal dynamics in tumor cells. In Aim 3, we will validate the role of mtHsp90s in animal models of metastasis in vivo. Our studies will verify the importance of the regulation of tumor bioenergetics by mitochondrial Hsp90s for metastatic disease, with the long term goal of identifying novel therapeutic targets to prevent the metastatic dissemination of cancer. The research plan proposed here will broaden my knowledge, critical thinking and overall background training in multiple fields of investigation including cell biology, biochemistry, molecular biology and cancer biology. I will also gain invaluable expertise in a broad range of quantitative approaches for the study of cell motility, UPR, tumor cell invasion and animals models of metastasis, in vivo. My goal for this training mechanism is to integrate all this new knowledge and formulate a comprehensive understanding of how key stress and metabolic pathways modulate metastasis. By completing the other components of my training plan I expect to become extremely competent in the planning, implementation and communication of my research results, develop a professional responsibility for conducting research, as well as learn key interpersonal skills essential to become an independent investigator. In summary, the present application is expected to support my successful establishment as a responsible and productive independent investigator.