Mechanisms of Dynamic Transcriptional Reprogramming in Metastasis Stem Cells

转移干细胞动态转录重编程的机制

• 批准号: 10340384
• 负责人: Karuna Ganesh
• 金额: $ 40.49万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10340384
• 关键词: 3' Untranslated Regions; Adherens Junction; Advanced Malignant Neoplasm; Aging; Binding; Binding Proteins; Biochemical; Biological Assay; Biological Models; Cancer Etiology; Cell Cycle; Cells; Cessation of life; Chromatin; Clinical; Colitis; Colon; Colorectal Cancer; Complex; Cytoplasmic Granules; Data; Development; Disseminated Malignant Neoplasm; Distant; E-Cadherin; Engineering; Epigenetic Process; Epithelial; Epithelial Cells; Family; Fluorescence; Gene Expression; Genes; Genetic; Genetic Transcription; Homeostasis; Immunofluorescence Immunologic; Immunoprecipitation; Impairment; Injections; Intestinal Neoplasms; Intestines; Knock-in; LGR5 gene; Maintenance; Malignant Neoplasms; Mediating; Mediator of activation protein; Messenger RNA; Modeling; Molecular; Mutation; Natural regeneration; Neoplasm Metastasis; Neural Cell Adhesion Molecule L1; Neurons; Neurosecretory Systems; Oncogenes; Organ; Organoids; Outcome; Output; Patient-Focused Outcomes; Patients; Phase; Phenotype; Physiologic pulse; Physiological; Primary Neoplasm; Proliferating; Proteins; RNA; RNA-Binding Proteins; Recurrence; Regulation; Reporter; Resistance; Role; Sampling; Stress; Structure; Structure of splenic vein; Time; Tissues; Untranslated Regions; Xenograft procedure; base; cancer cell; cancer stem cell; colorectal cancer metastasis; crosslink; in vivo; insight; intestinal epithelium; knock-down; mRNA Transcript Degradation; member; mouse model; neoplastic; neuroendocrine differentiation; novel; overexpression; progenitor; programs; protein complex; rectal; regenerative; regenerative cell; repaired; response; restoration; self-renewal; single cell mRNA sequencing; stem cell self renewal; stem cells; stemness; therapeutic target; therapy outcome; transcriptional reprogramming; transcriptome sequencing; transcriptomics; tumor; tumor initiation; tumor progression; wound healing

Metastasis causes >90% of cancer death. The persistence and lethality of metastasis is driven by cells capable of self-renewal, slow cell-cycling, tumor re-initiation, and therapy resistance, termed metastasis stem cells (MetSCs). Development of effective strategies for eliminating metastasis requires a better understanding of the mechanisms that MetSCs exploit for survival. We recently demonstrated that (1) disseminating colorectal cancers (CRC) undergo a dynamic phenotypic switch from an LGR5+ tumor-initiating cancer stem cell (CSC) state to a distinct LGR5lowL1CAM+ state required for metastasis. (2) This phenotypic plasticity of MetSCs is retained in ex vivo patient derived organoids, which can be used to dissect mechanisms of plasticity. (3) L1CAM+ MetSCs are functionally distinct from intestinal tumor-initiating LGR5+ CSCs: L1CAM is required for organoid formation, the regeneration of intestinal epithelium after colitis, and tumor formation after metastatic dissemination. But unlike LGR5, it is dispensable for epithelial homeostasis or intestinal tumor initiation. In contrast to tumor initiation, where homeostatic stem cells undergo oncogene-driven hyper proliferation in intact tissues, metastasis subverts a regenerative mechanism to survive and regrow outside an intact epithelial niche. (4) We have shown that the principal driver of L1CAM expression is loss of epithelial integrity itself, acting via loss of E-cadherin intercellular adherens junctions to transiently displace the transcriptional silencer REST/NSRF from chromatin in quiescent MetSCs, in turn derepressing expression of L1CAM and other genes required for tissue regeneration1. Proliferation, restoration of epithelial structures, and macrometastatic outgrowth, on the other hand, require high REST levels. Our evidence suggests that MetSCs cells are regenerative stem cells that emerge directly in response to loss of epithelial integrity to drive repair, a phenotype of physiological wound healing that is redeployed in MetSCs. In this proposal, we will define the molecular mechanism by which REST chromatin binding is dynamically regulated in MetSCs, and how this in turn enables cell fate plasticity from stemness to proliferation. Our preliminary data implicates the mRNA binding protein ZFP36L1/2 in REST- mediated metastatic plasticity. Project hypothesis: The ZFP36L1/2REST axis is a master regulator of cell fate plasticity in intestinal epithelial progenitors. Aim 1: Define the function of the ZFP36L1/2-REST axis in normal and neoplastic intestinal stem cell self-renewal, differentiation, and proliferation. Aim 2: Dissect the molecular mechanism of ZFP36L1/2-mediated cell fate plasticity. Aim 3: Determine the functional consequences of ZFP36L1/2-REST dynamic regulation in metastatic seeding and colonization. Results will define mechanisms of cancer progression and identify putative therapeutic targets to limit regenerative plasticity, with potential to impact clinical outcomes.

转移导致>90%的癌症死亡。转移的持久性和致命性是由能够 具有自我更新、缓慢细胞周期、肿瘤再启动和治疗抗性的转移干细胞 （MetSC）。发展消除转移的有效策略需要更好地理解肿瘤转移的机制。 MetSC利用的生存机制。我们最近证明，（1）播散性结直肠癌 癌症（CRC）经历从LGR 5+肿瘤起始癌症干细胞（CSC）的动态表型转换 从LGR 5低L1 CAM+状态转变为转移所需的不同LGR 5低L1 CAM+状态。(2)MetSC的这种表型可塑性是 保留在离体患者衍生的类器官中，其可用于解剖可塑性机制。(3)L1CAM+ MetSC在功能上不同于肠肿瘤引发的LGR 5 + CSC：L1 CAM是类器官所必需的 结肠炎后肠上皮的再生，以及转移后的肿瘤形成 传播。但与LGR 5不同的是，它是上皮稳态或肠道肿瘤发生的关键。在 与肿瘤发生相反，在肿瘤发生中，稳态干细胞在完整的细胞内经历癌基因驱动的过度增殖， 转移破坏了在完整上皮小生境外生存和再生的再生机制。 (4)我们已经证明L1 CAM表达的主要驱动力是上皮完整性本身的丧失，通过以下途径起作用： E-cadherin细胞间粘附连接的丢失，以瞬时取代转录沉默子REST/NSRF 从静止的MetSC中的染色质中，反过来去抑制L1 CAM和其他基因的表达， 组织再生上皮结构的增殖、恢复和大转移性生长， 另一方面，需要很高的REST级别。我们的证据表明，MetSCs细胞是再生干细胞， 直接响应于上皮完整性的丧失而出现，以驱动修复，这是生理性创伤的表型 在代谢干细胞中重新部署的愈合。在这个提议中，我们将定义REST 染色质结合在MetSC中受到动态调节，以及这反过来如何使细胞命运可塑性从 防止扩散。我们的初步数据表明，REST中的mRNA结合蛋白ZFP 36 L1/2， 介导的转移可塑性。项目假设：ZFP 36 L1/2 REST轴是细胞命运的主调节器 肠上皮祖细胞的可塑性。目标1：定义ZFP 36 L1/2-REST轴在正常情况下的功能 以及肿瘤性肠干细胞的自我更新、分化和增殖。目的2：剖析分子 ZFP 36 L1/2介导的细胞命运可塑性的机制。目标3：确定以下方面的功能后果： ZFP 36 L1/2-REST在转移播种和定殖中的动态调节。结果将确定 癌症进展，并确定假定的治疗靶点，以限制再生可塑性， 影响临床结果。