Identifying Fundamental Mechanisms that Mediate Resistance to Anti-Cancer Therapies

确定介导抗癌治疗耐药性的基本机制

• 批准号: 10311255
• 负责人: Elizabeth Marie Duncan
• 金额: $ 25.1万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10311255
• 关键词: Affect; Animals; Biochemical; Biological Assay; Cancer Center; Cancer Remission; Cells; Cellular biology; Chemoresistance; Chromatin; Cisplatin; Data; Development; Dose; Drug resistance; Exhibits; Gamma Rays; Genes; Genetic Transcription; Goals; Heterogeneity; Human; Kentucky; Link; Lysine; Maintenance; Malignant Neoplasms; Malignant neoplasm of lung; Measures; Mediating; Metabolic; Metabolism; Mitochondria; Modeling; Natural regeneration; Organoids; Phenotype; Planarians; Platyhelminths; Population; Regenerative capacity; Research; Resistance; Testing; Tissues; Tumor Suppressor Genes; Universities; Ursidae Family; base; cancer cell; cancer stem cell; cancer therapy; chemotherapy; epigenetic regulation; high resolution imaging; in vivo; lung cancer cell; novel; progenitor; stem; stem cell population; stem cells; tumor; tumor metabolism

A major obstacle to achieving long-term cancer remission is the ability of some cancer cells to resist therapy. Strikingly, the fundamental cell biology underlying therapy resistance in human tumors is remarkably similar to that which confers incredible regenerative capacity in many planarian species. In these flatworm species, even a small piece of excised tissue can recreate an entirely new animal. This remarkable ability relies on the maintenance of a heterogeneous pool of planarian stem cells that bear many similarities to cancer stem cells. For example, a subset of these cells can tolerate high doses of γ-radiation and restore the entire stem cell population. Yet little is known about the mechanisms that confer this tolerance and almost nothing is known about their resistance to chemotherapies. Preliminary research revealed that planarians show resistance to the drug cisplatin. Treatment of planarians with 80-100μM cisplatin induced a phenotype that broadly mimicked the development of chemoresistance in human cancers: animals exhibited an initial loss of tissue followed by regeneration. Based on these data and known effects of cisplatin, the central hypothesis is that cisplatin differentially affects mitochondrial function across the stem and progenitor populations, which differentially alters a conserved chromatin signature that marks tumor suppressor genes i.e., broad H3 lysine 4 trimethylation (H3K4me3), increases cellular heterogeneity, and promotes chemoresistance. The goal of this study is to leverage the remarkable functional similarities between human tumors and the planarian stem cell population to uncover fundamental mechanisms that link the development of chemoresistance to metabolic and epigenetic regulation in vivo through the following specific aims: 1) To identify cisplatin-responsive differences in mitochondrial function in stem and progenitor cell populations using mitochondrial probes, high resolution imaging, and biochemical assays. This study uses state-of the-art approaches to determine the metabolic heterogeneity of stem cells in vivo. 2) To establish mechanistic links between metabolism, chromatin state, and chemoresistance by perturbing metabolite availability and measuring the impact on H3K4me3, transcriptional heterogeneity, and chemoresistance. This study will reveal critical links between metabolic and epigenetic regulation in chemoresistance. 3) To assess the conservation of metabolic H3K4me3 regulatory mechanisms in lung cancer using established airway organoid models. This study will test the hypothesis that resistant lung cancer cells respond to cisplatin-induced ROS by reducing H3K4me3. The proposed research will uncover novel mechanisms and target genes underlying chemoresistance.

实现长期癌症缓解的主要障碍是一些癌细胞抵抗治疗的能力。引人注目的是，人类肿瘤中治疗抗性的基本细胞生物学与许多Planarian物种中赋予令人难以置信的再生能力的细胞生物学非常相似。在这些扁形虫物种中，即使是一小块切除的组织也可以再造一个全新的动物。这种非凡的能力依赖于维持一个异质的涡虫干细胞库，这些干细胞与癌症干细胞有许多相似之处。例如，这些细胞的子集可以耐受高剂量的γ辐射并恢复整个干细胞群。然而，人们对赋予这种耐受性的机制知之甚少，对它们对化疗的耐药性也几乎一无所知。初步研究显示，真涡虫对顺铂有抗药性。用80-100μM顺铂处理涡虫诱导了一种广泛模拟人类癌症中化学抗性发展的表型：动物表现出最初的组织损失，然后再生。基于这些数据和顺铂的已知作用，中心假设是顺铂在干细胞和祖细胞群体中差异性地影响线粒体功能，这差异性地改变了标记肿瘤抑制基因的保守染色质特征，即，广泛的H3赖氨酸4三甲基化（H3 K4 me 3），增加细胞异质性，并促进化学抗性。本研究的目标是利用人类肿瘤和真涡虫干细胞群体之间的显著功能相似性，通过以下特定目标揭示将体内化学抗性的发展与代谢和表观遗传调控联系起来的基本机制：1）使用线粒体探针，高分辨率成像，和生化分析。这项研究使用最先进的方法来确定体内干细胞的代谢异质性。2)通过干扰代谢物的可用性和测量对H3 K4 me 3、转录异质性和耐药性的影响，建立代谢、染色质状态和耐药性之间的机制联系。这项研究将揭示化学耐药性中代谢和表观遗传调节之间的关键联系。3)使用已建立的气道类器官模型评估肺癌中代谢H3 K4 me 3调节机制的保守性。本研究将检验耐药肺癌细胞通过减少H3 K4 me 3对顺铂诱导的ROS作出反应的假设。拟议的研究将揭示新的机制和靶基因的化学抗性。