The role of the nucleolus in human genome organization in normal and disease states

正常和疾病状态下核仁在人类基因组组织中的作用

• 批准号: 10468754
• 负责人: Daniel Richard Foltz
• 金额: $ 63.1万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-21 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10468754
• 关键词: 3-Dimensional; Affect; Architecture; Biology; Cancer Biology; Cell Nucleolus; Cell Nucleus; Cell Wall; Cells; Centromere; Characteristics; Chromatin; Chromosome Segregation; Chromosomes; Cis-Acting Sequence; Clinical Trials; Complex; Cytology; DNA; Data; Data Set; Disease; Eukaryota; Event; Frequencies; Gene Dosage; Gene Expression; Genetic Transcription; Genome; Genome Stability; Genomics; Goals; Health; Heterochromatin; Histones; Human; Human Chromosomes; Human Genome; Immune; Immune signaling; Infection; Inflammatory; Innate Immune System; Interphase Cell; Investigation; Kinetics; Label; Learning; Link; Lipopolysaccharides; MAP Kinase Gene; Malignant Neoplasms; Maps; Measurement; Mediating; Methods; Mitotic spindle; Modification; Molecular; Mus; Natural Immunity; Neoplasm Metastasis; Normal Cell; Nuclear; Nucleolar Proteins; Organelles; Phase; Prevalence; Process; Property; Proteins; RNA; RNA-Binding Proteins; Repetitive Sequence; Research Personnel; Ribosomal RNA; Ribosomes; Role; Satellite DNA; Series; Shapes; Signal Pathway; Signal Transduction; Site; Stimulus; Stress; Structure; Surface; System; Testing; Therapeutic; Transducers; Untranslated RNA; anticancer treatment; base; cancer cell; carcinogenesis; carcinogenicity; cell type; cellular targeting; chromatin modification; chromosome missegregation; chromosome movement; deep sequencing; environmental stressor; experimental study; extracellular; functional outcomes; genome-wide; genomic locus; histone modification; macrophage; malignant phenotype; member; monocyte; neoplastic cell; novel; p38 Mitogen Activated Protein Kinase; pathogen; recruit; response; therapeutic lead compound; tool; tumor xenograft

7. Project Summary / Abstract In all eukaryotes, the largest nuclear body is the nucleolus, a phase-separated, non-membrane bound organelle specialized for the synthesis of ribosomal RNAs and their assembly into ribosomes. Additionally, the exterior of the nucleolus is a hub for interactions with multiple specific DNA loci, thereby contributing to the three-dimensional architecture of the eukaryotic nucleus. Nucleolus-genome interactions are intimately connected to processes central to human health. For example, nucleolar-associated DNA is highly enriched in centromeric repetitive sequences. Centromeres, the sites of chromosome attachment to mitotic spindles, are fundamentally important for proper chromosome segregation. Several nucleolar proteins have been implicated in centromere-nucleolar interactions, and several centromeric proteins prominently reside in nucleoli in interphase cells. We have found that the nucleolar- centromeric interactions are regulated during cellular differentiation and are greatly increased in cancer cells. However, the mechanisms that regulated these interactions remain unknown. Not only do cancer cells display increased centromere-nucleolar interactions, they also frequently contain a perinucleolar compartments (PNC), a complex cytological feature that is absent in non-tumor cells. PNCs are located on the surface of nucleoli and contain multiple RNA species and RNA-binding proteins. We demonstrate here that these bodies also contain specific DNA loci, some of which encode non-coding RNAs retained within PNCs. A candidate cancer therapeutic termed metarrestin was isolated based on its ability to dissociate PNCs; metarrestin is currently in clinical trials based on its ability to reduce metastasis in human tumor xenograft experiments. Importantly for this proposal, we have observed that metarrestin also perturbs centromere-nucleolar interactions. We also present data that centromere-nucleolus interactions are perturbed in macrophages upon exposure the bacterial lipopolysaccharide (LPS), a canonical stimulus for the innate immune system. We also show that this response is blocked upon inhibition of specific signaling pathways. These changes are accompanied by altered nuclear distribution of the H3K27me3, a histone modification characteristic of facultative heterochromatin. Altogether, the central theme of this proposal is that the factors that govern centromere-nucleolus interactions are important for understanding chromosome missegregation, metastasis, and innate immunity. We plan a series of synergistic experiments to learn more about the underlying mechanisms. For example, we will test whether the centromeric activity of neocentromeres generates nucleolar associations, or if instead that is a property of centromeric satellite repeats regardless of activity. We will take candidate and unbiased approaches to finding centromeric proteins required for nucleolar interactions. We will characterize how metarrestin affects association of DNA loci with PNCs and nucleoli, and we will define cis-acting loci involved in PNC association. We will characterize the signaling pathways required for signaling-mediated disruption of nucleolar-centromeric interactions in macrophages. Results from these studies will allow for subsequent testing of universality. For example, do signaling components in macrophages also operate in tumor cells when treated with the therapeutic metarrestin? In this manner, this collaborative proposal will unite questions from diverse experimental systems to answer questions about the fundamental links between nuclear organization and human health.

7. 项目摘要/摘要