Therapeutic Targeting of Autophagy-Dependent Cancer

自噬依赖性癌症的治疗靶向

• 批准号: 10533694
• 负责人: Christina G Towers
• 金额: $ 3.13万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-11 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10533694
• 关键词: Affect; Autophagocytosis; Autophagosome; Biological Assay; Cancer Biology; Cell Survival; Cell membrane; Cells; Clathrin; Confocal Microscopy; Critical Pathways; Doctor of Philosophy; Endocytosis; Flow Cytometry; Goals; Health; Homeostasis; Homo; Image; Learning; Lysosomes; Maintenance; Malignant Neoplasms; Measures; Mediating; Mentors; Mitochondria; Molecular Cloning; Movement; Organelles; Pathway interactions; Play; Population; Process; Production; Proteins; Publishing; Resistance; Role; Signal Transduction; Structure; Techniques; Testing; Training; Vesicle; Work; cancer cell; cancer health disparity; career; cell growth; design; dimer; experience; experimental study; falls; insight; knock-down; meetings; mitochondrial membrane; programs; ratiometric; small hairpin RNA; sorting nexins; therapeutic target; tool; trafficking

PROJECT SUMMARY Mitochondria are key organelles in the cell and regulate many processes including energy production and cell signaling. Many cancer cells are dependent on functional mitochondria for cell survival. Mitochondrial homeostasis is therefore critical and is tightly regulated. Damaged mitochondria are turned over by a select form of autophagy, known as mitophagy, where an intact mitochondrion is engulfed by an autophagosome which then fuses with a lysosome to facilitate degradation. It has been previously shown that cancer cells are dependent on core autophagy regulators like ATG7 and FIP200 for survival, but rare cells from these populations can survive loss of this core pathway. The ATG7 KO cells that were derived from highly autophagy dependent cells switched to become autophagy independent. Despite a lack of canonical mitophagy, the autophagy deficient cells can still degrade mitochondria and maintain mitochondrial function. It was recently published that cells that survive loss of autophagy can instead form small mitochondrial derived vesicles (MDVs) that can directly fuse with lysosomes to maintain mitochondrial homeostasis. Cells with more MDVs are dependent on them for mitochondrial function and overall survival. MDVs are highly understudied, but this work suggests they could be a potential new target in cancer cells. The work proposed here will include more mechanistic studies to understand how MDVs are regulated. The only known regulator of these vesicles is the endocytosis-regulating sorting nexin, SNX9, but how it regulates MDV formation is unknown. These studies will include structure-function analysis to dissect the specific roles of each domain within SNX9 to determine how it regulates MDV formation and trafficking as well as its role in mitochondrial homeostasis and overall cell survival. SNX18 is homologous to SNX9 and can compensate for its role in endocytosis. These studies will test the hypothesis that SNX18 is also important in MDVs. A significant goal of this project is also to train and mentor Sienna. During these studies she will learn new techniques including molecular cloning, flow cytometry, and mitochondrial function assays among others. She will also learn how to develop her own hypotheses and design experiments with critical controls to drive her own project forward. Her next career goal is to get a PhD in cancer biology with a focus on cancer disparities. This project will provide her with the necessary tools and techniques as well additional course work to help prepare her for PhD programs. She will also attend national meetings like ABRCMS. This project is designed to help her make the successful transition into graduate programs in the Fall of 2023.

项目总结 线粒体是细胞中的关键细胞器，调节许多过程，包括能量产生和细胞 发信号。许多癌细胞的生存依赖于功能正常的线粒体。线粒体 因此，动态平衡至关重要，并受到严格监管。受损的线粒体被一种精选的 自噬的一种形式，称为有丝分裂吞噬，即完整的线粒体被自噬小体吞噬 然后与溶酶体融合以促进降解。此前已有研究表明，癌细胞 依赖ATG7和FIP200等核心自噬调节因子生存，但这些细胞中的稀有细胞 种群可以在失去这一核心途径后存活下来。来自高度自噬的ATG7 KO细胞 依赖细胞转变为自噬非依赖细胞。尽管缺乏规范的有丝分裂，但 自噬缺陷细胞仍然可以降解线粒体并维持线粒体功能。那是最近的事 发表的研究表明，在自噬丧失后存活的细胞可以形成小的线粒体衍生的小泡 (MDV)可以直接与溶酶体融合以维持线粒体的动态平衡。具有更多MDV的细胞 线粒体功能和整体生存都依赖于它们。MDV的研究严重不足，但这一点 研究表明，它们可能成为癌细胞的潜在新靶点。这里提出的工作将包括更多 机制研究，以了解MDV是如何受到监管的。已知的唯一调节这些囊泡的是 内吞作用调节分选Nexin，SNX9，但它如何调节MDV的形成尚不清楚。这些研究将 包括结构-功能分析，以剖析SNX9中每个域的特定角色，以确定它是如何 调节MDV的形成和运输，以及它在线粒体稳态和整个细胞中的作用 生死存亡。SNX18与SNX9同源，可以补偿其在内吞作用中的作用。这些研究将检验 假设SNX18在MDV中也很重要。该项目的一个重要目标也是培训和 西耶娜导师。在这些研究中，她将学习新技术，包括分子克隆、流式细胞仪、 以及线粒体功能分析等。她还将学习如何发展她自己的假设和 设计关键控制的实验，以推动她自己的项目向前发展。她的下一个职业目标是获得博士学位 在癌症生物学方面，重点是癌症差异。这个项目将为她提供必要的工具和 技术以及额外的课程工作，帮助她为博士课程做准备。她还将参加全国 像ABRCMS这样的会议。这个项目的目的是帮助她顺利过渡到研究生 2023年秋季的计划。