Mitochondrial quality control as a selective vulnerability in cancers with chromosome 10q deletion

项目摘要 在癌症的发展和进展中，细胞经常删除包括肿瘤在内的大片DNA区域 抑制基因(TSG)。由于接近，与TSG相邻的基因通常是共缺失的，这 通常不会影响细胞健康。尽管如此，作为乘客突变的基因缺失可能会使 癌细胞对药物或其他突变的易感性是健康的、基因上的“正常”细胞所不具备的。 以这种脆弱性为靶点杀死癌细胞而不损害健康细胞的做法唤起了遗传学原理 “合成杀伤力”。当细胞单独耐受其中一种时，两种突变被认为是合成致命的， 但当它们同时发生时就会死亡。因此，识别具有共缺失基因的合成致死基因 可以提供新的药物靶点。 在癌症中最常见的缺失抑癌基因之一是PTEN，它编码一种 通常会对抗细胞生长和存活的磷酸酶。在人类的上游只有40千个碱基 染色体10q23上的PTEN基因座是ATAD1的基因座，它编码一种进化上保守的 线粒体动态平衡所必需的ATPase。ATAD1提取尾锚定(TA)蛋白 线粒体膜外(OMM)。TA蛋白在C-端具有单程跨膜结构域。 终点站。我们进行了全基因组CRISPR筛查，以确定仅在 缺乏ATAD1，因为对于与PTEN共缺失ATAD1的肿瘤来说，这些将是理想的药物靶点。 我们屏幕上的多次点击表明ATAD1参与了细胞凋亡的调节，这一过程严重依赖于 OMM中的TA蛋白。具体地说，一类被称为BH3-的TA蛋白转位到OMM- 只有蛋白质被认为可以诱导细胞凋亡。我们假设ATAD1只提取尾部锚定的BH3 来自线粒体膜外膜的蛋白质，以防止异常的细胞凋亡。目前的建议 描述我们将如何使用遗传学、生物化学和动物模型来检验这一假说。小分子 仅BH3蛋白的模拟被批准用于癌症患者，因此两者之间的联系 ATAD1和细胞凋亡可能对精确肿瘤学有重要意义。 我和我的赞助商一起制定了一项研究培训计划，其中包括临床培训 为我的职业生涯做好准备，成为一名内科科学家。我的研究训练计划将帮助我发展技能 细胞生物学和生物化学，这是我的主要赞助人贾里德·鲁特博士和他的实验室的专长。 我的临床培训赞助人道格拉斯·格罗斯曼博士是一名内科科学家和皮肤病教授， 他将帮助我获得强调癌症诊断和治疗的临床经验。我会指挥 在犹他大学生物化学系充满活力的社区进行的研究，那里有一个 一群才华横溢的研究人员致力于培养年轻科学家。

PROJECT ABSTRACT In the development and progression of cancer, cells frequently delete large regions of DNA that include tumor suppressor genes (TSGs). By virtue of proximity, genes that neighbor TSGs are often co-deleted, which usually does not affect cell fitness. Nonetheless, deletion of a gene as a passenger mutation can make a cancer cell vulnerable to drugs or other mutations in ways that healthy, genetically “normal” cells are not. Targeting such vulnerabilities to kill cancer cells and leave healthy cells unharmed evokes the genetic principle of “synthetic lethality.” Two mutations are said to be synthetic lethal when cells tolerate either one individually, but die when they occur together. Thus, identification of genes that are synthetic lethal with co-deleted genes can provide new drug targets. One of the most frequently deleted tumor suppressor genes in cancer is PTEN, which encodes a phosphatase that normally antagonizes cell growth and survival. Only 40 kilobases upstream of the human PTEN locus on chromosome 10q23 is the locus for ATAD1, which encodes an evolutionarily conserved ATPase that is essential for mitochondrial homeostasis. ATAD1 extracts tail-anchored (TA) proteins from the outer mitochondrial membrane (OMM). TA proteins possess a single-pass transmembrane domain at the C- terminus. We conducted a genome-wide CRISPR screen to identify genes that are essential only in the absence of ATAD1, as these would make ideal drug targets for tumors that co-delete ATAD1 with PTEN. Multiple hits from our screen implicate ATAD1 in the regulation of apoptosis, a process that critically depends on TA proteins in the OMM. Specifically, translocation to the OMM by a class of TA proteins known as BH3- only proteins is thought to induce apoptosis. We hypothesize that ATAD1 extracts tail-anchored BH3-only proteins from the outer mitochondrial membrane to prevent aberrant apoptosis. The present proposal describes how we will test this hypothesis using genetics, biochemistry, and animal models. Small molecule mimetics of BH3-only proteins are approved for use in cancer patients, and thus the connection between ATAD1 and apoptosis could have major implications for precision oncology. Together with my sponsors I have generated a research training plan that integrates clinical training and will prepare me for a career as a physician-scientist. My research training plan will help me develop skills in cell biology and biochemistry, which are the specialties of my primary sponsor, Dr. Jared Rutter, and his lab. My clinical training sponsor, Dr. Douglas Grossman, is a physician-scientist and Professor of Dermatology, and he will help me gain clinical experience that emphasizes the diagnosis and treatment of cancer. I will conduct research in the vibrant community of the Department of Biochemistry at the University of Utah, which houses a diverse group of talented investigators dedicated to training young scientists.