Identification of Novel Mechanisms of Autophagy Regulation for Cancer

癌症自噬调节新机制的鉴定

• 批准号: 9139472
• 负责人: Anne M STROHECKER
• 金额: $ 19.34万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-07 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9139472
• 关键词: Ablation; Adenocarcinoma; Animals; Antineoplastic Agents; Apoptotic; Area; Attention; Autophagocytosis; Autophagosome; Benign; Binding; Biological; Biological Assay; Breeding; Cancer Institute of New Jersey; Catabolic Process; Cell Death; Cell Line; Cells; Complex; Data; Defect; Disease; Doctor of Philosophy; Ensure; Family; Foundations; GTF2H1 gene; Genes; Genetically Engineered Mouse; Glutamine; Growth; Health; Homeostasis; Hydrolysis; Impairment; In Vitro; Investigation; K22 Award; Laboratories; Link; Lipids; Lung; Lung Neoplasms; Lysosomes; Maintenance; Malignant Neoplasms; Malignant neoplasm of lung; Mammary Tumorigenesis; Measures; Mechanics; Membrane Fusion; Membrane Protein Traffic; Metabolic; Metabolic stress; Metabolism; Mitochondria; Modality; Monitor; Monomeric GTP-Binding Proteins; Mus; Non-Small-Cell Lung Carcinoma; Oncogenic; Organelles; Oxyphilic Adenoma; PPAR gamma; Paper; Pathway interactions; Patients; Phenocopy; Phosphotransferases; Physiological; Play; Postdoctoral Fellow; Process; Production; Proteins; Recycling; Regulation; Regulator Genes; Reporter; Research; Research Personnel; Resistance; Role; Starvation; Stress; System; Testing; Therapeutic; Time; Transgenic Mice; Tumor Burden; Tumor-Derived; Ubiquitination; Universities; Vesicle; Work; cancer diagnosis; cancer therapy; career; drug development; experience; fatty acid oxidation; in vivo; inhibition of autophagy; inhibitor/antagonist; innovation; late endosome; lipid biosynthesis; lipid metabolism; lung tumorigenesis; malignant breast neoplasm; meetings; member; mitochondrial dysfunction; mitochondrial metabolism; mouse model; neoplastic cell; new therapeutic target; novel; novel strategies; novel therapeutics; overexpression; prevent; programs; rab GTP-Binding Proteins; research study; small hairpin RNA; success; therapeutic target; trafficking; trans-Golgi Network; tumor; tumor growth; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): I earned my Ph.D. in the laboratory of Dr. Vincent Cryns at Northwestern University where I focused on mechanisms of apoptotic cell death in breast cancer. Currently, I am a postdoctoral fellow in the laboratory of Dr. Eileen White at the Rutgers Cancer Institute of New Jersey where I am studying the role of autophagy in lung tumorigenesis in vitro and in vivo. I discovered that autophagy sustains the growth of BrafV600E-driven tumors by maintaining mitochondrial glutamine metabolism. Autophagy ablation in these animals results in an accumulation of defective mitochondria, alteration in tumor cell fate from adenocarcinomas to benign oncocytomas, and an increase in overall survival. This work establishes a functional link between autophagy and the continued growth of lung tumors, suggesting that autophagy inhibition would be a valuable therapeutic strategy in these tumors. I would like to expand on these exciting results as an independent investigator. My research program will be devoted to the study of autophagy in cancer, with an emphasis on how to modulate the pathway as a therapeutic modality in cancer. I have already taken a significant step in this direction by conducting an shRNA screen for autophagy modulators to identify novel mechanisms of autophagy regulation. I identified many vesicle trafficking components, in particular a subset of the Rab GTPases, central organizers of intracellular trafficking, and metabolically relevant genes, such as kinases involved in lipid metabolism, which are predicted to be therapeutic targets for autophagy related diseases and cancer. I am now studying the mechanisms of autophagy regulation and investigating the functional significance of suppressing autophagy by these genes in mouse models of NSCLC. Receipt of the K22 award at this point in my career would provide protected time to gain additional experience and move into new research areas, as well as generate additional data and papers necessary to successfully compete for an R01, thus ensuring my success as an independent investigator. Project Summary Autophagy is a catabolic process that sustains metabolism by recycling intracellular components for use in biosynthetic processes and eliminating damaged proteins and organelles whose accumulation is toxic. It is increasingly clear that tumor cells exploit autophagy as a means to meet their elevated metabolic demands. I discovered that autophagy is required to support mitochondrial metabolism and growth of lung tumors driven by oncogenic BrafV600E. Autophagy ablation resulted in alteration of tumor cell fate and prolonged survival. Similar results have been obtained with lung tumors driven by Kras; and mammary tumorigenesis is blunted in mouse models with deficiencies in components required for nucleation of the autophagosome suggesting that autophagy inhibition is likely to be a powerful therapeutic approach for cancer. This project determines the mechanism of autophagy inhibition by two of the most promising novel autophagy regulators identified by my shRNA screen, the small GTPase Rab9 and the pseudokinase Trib3, and evaluates whether these genes can alter tumor progression and survival in a mouse model of NSCLC. Rab9, a member of the Ras-related small GTPase superfamily, regulates traffic between the late endosome and the trans Golgi network. I hypothesize that it inhibits autophagy by diverting components needed for phagophore nucleation to the endosomal pathway, or by interfering with lipid donation to the expanding autophagosome. The pseudokinase Trib3 plays a central role in lipid homeostasis by controlling the stability of acetyl-coA carboxylase (ACC) and by inhibiting the master regulator of adipogenesis, PPARγ. I hypothesize that Trib3 enhances cellular energy levels to obviate the need for autophagy. These studies are important, and have the potential to identify novel biological mechanisms and approaches to lung cancer therapy as well as extend our understanding of the mechanics and regulation of autophagy.

描述（由申请人提供）：我获得了博士学位。在西北大学文森特·克林斯博士的实验室里，我专注于乳腺癌细胞凋亡的机制。目前，我是新泽西罗格斯癌症研究所艾琳白色博士实验室的博士后研究员，在那里我正在研究自噬在体外和体内肺肿瘤发生中的作用。我发现自噬通过维持线粒体谷氨酰胺代谢来维持BrafV 600 E驱动的肿瘤的生长。这些动物中的自噬消融导致缺陷线粒体的积累，肿瘤细胞命运从腺癌改变为良性嗜酸细胞瘤，以及总生存率的增加。这项工作建立了自噬和肺肿瘤持续生长之间的功能联系，表明自噬抑制将是这些肿瘤中有价值的治疗策略。我想以独立调查员的身份来扩展这些令人兴奋的结果。我的研究计划将致力于癌症自噬的研究，重点是如何调节作为癌症治疗方式的途径。我已经在这个方向上迈出了重要的一步，通过对自噬调节剂进行shRNA筛选，以确定自噬调节的新机制。我鉴定了许多囊泡运输组分，特别是Rab GTP酶的一个子集，细胞内运输的中心组织者，以及代谢相关基因，如参与脂质代谢的激酶，这些基因被预测为自噬相关疾病和癌症的治疗靶点。我现在正在研究自噬调控的机制，并调查这些基因在NSCLC小鼠模型中抑制自噬的功能意义。在我职业生涯的这一点上获得K22奖将提供受保护的时间来获得额外的经验并进入新的研究领域，以及生成成功竞争R 01所需的额外数据和论文，从而确保我作为独立研究者的成功。 自噬是一种分解代谢过程，通过回收细胞内成分用于生物合成过程，并消除累积有毒的受损蛋白质和细胞器来维持新陈代谢。越来越清楚的是，肿瘤细胞利用自噬作为满足其升高的代谢需求的一种手段。我发现自噬是支持线粒体代谢和致癌BrafV 600 E驱动的肺肿瘤生长所必需的。自噬消融导致肿瘤细胞命运的改变和生存期的延长。Kras驱动的肺肿瘤也获得了类似的结果;在小鼠模型中，乳腺肿瘤发生减弱，自噬体成核所需的组分缺乏，这表明自噬抑制可能是一种强大的癌症治疗方法。 该项目确定了由我的shRNA筛选鉴定的两种最有前途的新型自噬调节剂，小GTTRab 9和假激酶Trib 3抑制自噬的机制，并评估这些基因是否可以改变NSCLC小鼠模型中的肿瘤进展和存活率。Rab 9是Ras相关的小G蛋白超家族的成员，调节晚期内体和高尔基体网络之间的交通。我推测，它抑制自噬转移所需的吞噬细胞成核的内体途径的组件，或通过干扰脂质捐赠扩大自噬体。假激酶Trib 3通过控制乙酰辅酶A羧化酶（ACC）的稳定性和抑制脂肪形成的主要调节因子PPARγ在脂质稳态中起着重要作用。我假设Trib 3增强细胞能量水平以满足自噬的需要。这些研究很重要，有可能确定肺癌治疗的新生物学机制和方法，并扩展我们对自噬机制和调控的理解。