Defining the role of Taiman, the Drosophila homolog of AIB1, as a super-competitor in developing epithelia

定义 Taiman（AIB1 的果蝇同源物）作为上皮细胞发育中超级竞争者的作用

• 批准号: 10626071
• 负责人: Colby Kristina Schweibenz
• 金额: $ 4.77万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10626071
• 关键词: Affinity Chromatography; Alleles; Apoptosis; Binding; Biochemical; Biological Assay; Breast; Cancer Biology; Cell Survival; Cells; Cessation of life; Classification; Complex; Data; Development; Diagnosis; Disease; Dose; Drosophila genus; Drosophila melanogaster; Ecdysone; Elements; Embryo; Ensure; Environment; Epiblast; Epithelial Cells; Epithelium; Estrogens; Genes; Genetic Transcription; Goals; Growth; Homologous Gene; Hormones; Human; Immunofluorescence Immunologic; Interruption; Invaded; Knowledge; Learning; Ligands; Link; Localized Malignant Neoplasm; MYC gene; Malignant Neoplasms; Measures; Mediating; Messenger RNA; Methods; Modeling; Modification; Molecular; NCOA3 gene; Neoplasm Metastasis; Nuclear Hormone Receptors; Oncogene Activation; Oncogenes; Outcome; Pathway interactions; Population; Process; Production; Progesterone; Proliferating; Proteins; Proteome; Publishing; RNA Interference; Receptor Signaling; Research; Ribosomes; Role; Scientist; Signal Transduction; System; Testing; Therapeutic; Tissues; Transcription Coactivator; Translating; Tumor Suppressor Proteins; United States; Wing; Woman; Work; breast cancer progression; cancer cell; cancer therapy; cell type; cofactor; cost; design; dosage; ecdysone receptor; effective therapy; experimental study; fitness; genetic variant; hormonal signals; insight; mRNA Translation; malignant breast neoplasm; model organism; novel; novel therapeutics; overexpression; pro-apoptotic protein; receptor; statistics; steroid hormone; steroid hormone receptor; tool

PROJECT SUMMARY Invasive breast cancer is a deadly disease, killing ~42,000 women each year and costing the United States over $16.5 billion annually. The complicated disease mechanisms that drive breast cancer are still insufficiently understood to confidently design therapeutics. One mechanism emerging as a potential driver for local invasion in breast and other cancers is ‘cell competition.’ This phenomenon occurs when two different cell populations with different ‘fitness’ levels are juxtaposed in the same tissue. High fitness cells (called ‘winners’) grow more rapidly and kill off slower growing neighbors (called ‘losers’) by apoptosis. Cancer cells acquire ‘winner’ status by activating oncogenes. Oncogenes that confer ‘winner’ status are called ‘super-competitors.’ Our lab uses the model organism, Drosophila melanogaster, to study conserved growth and proliferation pathways that are altered in human cancer. In previous work we showed that Drosophila Taiman (Tai, AIB1 in humans), a co-activator of the Ecdysone steroid hormone receptor (EcR), is a candidate super-competitor and imparts ‘winner’ status to cells via production of the secreted, pro-apoptotic protein Spätzle (Spz), a Toll receptor ligand. We have also shown that Tai binds the Yorkie (Yki) coactivator protein, the main target of the Hippo tumor suppressor pathway, and that Yki:Tai collaboratively drive expression of pro-growth genes. However, we do not fully understand how Tai drives neighbor killing, or whether it requires interactions with EcR and/or Yki. Moreover, classifying Tai as a ‘super-competitor’ requires evidence that lowering the Tai dose confers ‘loser’ status relative to wildtype cells. In the following three Aims, I will test my hypothesis that Tai acts as a super-competitor through either its interaction with Yki (Hippo pathway) or EcR (ecdysone pathway), test the relative fitness of Tai-overexpressing (Taihigh), wildtype (Taiwt), and Tai hypomorphic (Tailow) cells, and carry out experiments to identify cell competition factors regulated by Tai. In Aim 1, I will assess the effects of elevated or reduced Tai on cell survival in homotypic vs. heterotypic environments. To link to our published data, I will also investigate the requirement of the Spz/Toll pathway in these contexts. In Aim 2, I will use candidate-based approaches to test the requirements for Yki/Hippo and EcR signaling in Tai-driven killing of neighbor cells. Finally in Aim 3, I will use the unbiased, discovery-based method Translating Ribosome Affinity Purification with sequencing (TRAP-Seq) to identify the Tai-induced translated proteome in wing cells and candidate ‘competition’ factors within it. These aims will define the molecular mechanisms underlying Tai-regulated cell competition in epithelial tissue. This work could also reveal a link between cell competition and steroid hormone signaling, which could be a novel element of cancer biology. The pathways that will be uncovered by this work will have long-term impacts, as knowledge of cell competition mechanisms could be applied to mammalian models to learn more about cancer emergence and progression. Specifically, knowledge gained from this research could lead to greater understanding of the role of the human homolog AIB1 in breast cancer and lead to the development of potential new therapeutics.

项目概要 侵袭性乳腺癌是一种致命的疾病，每年夺去约 42,000 名女性的生命，给美国造成超过 每年 165 亿美元。驱动乳腺癌的复杂疾病机制仍不够充分 了解如何自信地设计治疗方法。一种机制成为局部入侵的潜在驱动因素 在乳腺癌和其他癌症中，这种现象是“细胞竞争”。当两种不同的细胞群 具有不同“健康”水平的并置在同一组织中。高适应度细胞（称为“获胜者”）生长得更多 迅速并通过细胞凋亡杀死生长较慢的邻居（称为“失败者”）。癌细胞获得“胜利者”地位 通过激活癌基因。赋予“获胜者”地位的癌基因被称为“超级竞争者”。我们的实验室使用 模型生物，黑腹果蝇，研究被改变的保守生长和增殖途径 在人类癌症中。在之前的工作中，我们表明果蝇 Taiman（Tai，人类中的 AIB1）是 蜕皮激素类固醇激素受体（EcR）是候选的超级竞争者，并赋予“获胜者”地位 细胞通过产生分泌的促凋亡蛋白 Spätzle (Spz)（一种 Toll 受体配体）来实现这一目标。我们还有 表明 Tai 结合了 Yorkie (Yki) 共激活蛋白，这是 Hippo 肿瘤抑制途径的主要靶标， Yki:Tai 协同驱动促生长基因的表达。然而，我们并不完全了解如何 Tai 驱动邻居杀戮，或者是否需要与 EcR 和/或 Yki 交互。此外，将 Tai 分类为 “超级竞争者”需要证据证明降低 Tai 剂量会导致相对于野生型细胞处于“失败者”状态。 在以下三个目标中，我将检验我的假设，即 Tai 通过其任一方式充当超级竞争对手 与 Yki（Hippo 途径）或 EcR（蜕皮激素途径）相互作用，测试 Tai 过度表达的相对适应性 （Taihigh）、野生型（Taiwt）和Tai亚形（Tailow）细胞，并进行实验以鉴定细胞竞争 受Tai调节的因素。在目标 1 中，我将评估 Tai 升高或降低对同型细胞存活的影响 与异型环境。为了链接到我们发布的数据，我还将调查 Spz/Toll 的要求 在这些背景下的路径。在目标 2 中，我将使用基于候选的方法来测试 Yki/Hippo 的要求 Tai 驱动的邻近细胞杀伤中的 EcR 信号传导。最后，在目标 3 中，我将使用公正的、基于发现的方法 方法翻译核糖体亲和纯化与测序（TRAP-Seq）来鉴定Tai诱导的 翻译翼细胞中的蛋白质组和其中的候选“竞争”因子。这些目标将定义 Tai调节上皮组织细胞竞争的分子机制。这项工作还可以揭示 细胞竞争和类固醇激素信号之间的联系，这可能是癌症生物学的一个新元素。 这项工作将揭示的途径将产生长期影响，因为细胞竞争的知识 机制可以应用于哺乳动物模型，以更多地了解癌症的出现和进展。 具体来说，从这项研究中获得的知识可以使人们更好地理解人类的作用 乳腺癌中的同源 AIB1 并导致潜在新疗法的开发。