Arsenic carcinogenesis and disruption of histone variant H3.3 assembly

砷致癌和组蛋白变体 H3.3 组装的破坏

• 批准号: 10407027
• 负责人: Max Costa
• 金额: $ 54.15万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-06 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10407027
• 关键词: Amino Acids; Arsenic; Attenuated; Binding; Binding Proteins; Carcinogens; Cell Cycle; Cell Cycle Arrest; Cells; ChIP-seq; Chromatin Modeling; Chromatin Structure; Chromosome Segregation; Coupled; DNA Repair; Defect; Development; Ectopic Expression; Enhancers; Environment; Epigenetic Process; Exposure to; Gene Expression; Genes; Genetic Transcription; Genome Stability; Genomic Instability; Heterochromatin; Histone H3; Histones; Link; Lung; Malignant Neoplasms; Malignant neoplasm of liver; Malignant neoplasm of lung; Malignant neoplasm of urinary bladder; Maps; Mass Spectrum Analysis; Mediating; Messenger RNA; Metals; Molecular Chaperones; Mus; Nucleosomes; Nude Mice; Persons; Play; Poly A; Poly(A) Tail; Polyadenylation; Post-Translational Protein Processing; Process; Property; Proteins; RNA; Regulator Genes; Regulatory Element; Renal carcinoma; Role; Site; Skin Cancer; Structure; Testing; Therapeutic Intervention; Tissues; Variant; arsenic carcinogenesis; arsenic-induced carcinogenesis; base; cancer type; carcinogenesis; carcinogenicity; cell growth; cell transformation; exposed human population; genome-wide; histone modification; human disease; in vivo; innovation; knock-down; mutant; novel; overexpression; prevent; promoter; stem; therapeutically effective; transcriptome; transcriptome sequencing; tumor

PROJECT SUMMARY Arsenic has been identified as a prominent causal agent in skin, lung, bladder, and liver cancers. Arsenic contamination impacts hundreds of millions of people in the world. The carcinogenicity of arsenic coupled with an alarmingly large number of people exposed creates an urgency for studying and understanding its carcinogenic mechanisms so effective therapeutic intervention can be initiated. Unlike most other genes, canonical histone messenger RNAs (mRNAs) such as histone H3.1 mRNA do not end with a poly(A) tail, instead they have a stem-loop structure at their 3’ end. Stem-loop binding protein (SLBP) attaches to the stem- loop RNA structure that is required for 3’-processing of the canonical histone mRNA. Previously we found that arsenic exposure downregulates SLBP levels, allowing the canonical histone H3.1 mRNA to acquire a poly(A) tail. Polyadenylation of H3.1 mRNA appeared to be carcinogenic, since it induced transcriptional deregulation, cell cycle arrest, and genomic instability, and facilitated anchorage-independent cell growth and tumor formation in nude mice. These effects were likely resulting from disruption of variant histone H3.3 assembly, because genome-wide histone mapping showed that polyadenylation of H3.1 mRNA compromised the H3.3 assembly at the sites critical for transcription, cell identity, and heterochromatin spreading. H3.3 plays important roles in transcription, efficient DNA damage repair, proper segregation of chromosomes, and development. The knockdown of H3.3, which mimics disruption of H3.3 assembly, induced cell transformation. Furthermore, H3.3 mutants have been linked to various type of cancers, underscoring importance of H3.3 in carcinogenesis. Based on these observations, we hypothesize that disruption of H3.3 assembly resulting from polyadenylation of canonical histone H3.1 mRNA is a significant contributor to arsenic-induced carcinogenesis. To test this hypothesis, we will determine the mechanisms by which polyadenylated canonical histone H3.1 mRNA disrupts assembly of the variant H3.3 in Aim 1, determine whether defective H3.3 assembly is responsible for arsenic-induced aberrant transcription, cell cycle arrest as well as genomic instability in Aim 2, and determine the role for disruption of H3.3 assembly in arsenic-induced cell transformation and explore whether arsenic exposure disrupts H3.3 assembly in vivo in Aim 3. The significance and innovation of these studies lie in the potential to reveal disruption of H3.3 assembly as a novel mechanism of arsenic-induced carcinogenesis.

项目摘要 砷已被确定为皮肤，肺，膀胱和肝癌的重要因果剂。砷 污染影响了世界上数亿人。砷的致癌性与 令人震惊的大量人遭受了研究和理解其的紧迫性 可以启动这种有效的治疗干预措施的致癌机制。与大多数其他基因不同， 典型组蛋白信使RNA（mRNA），例如组蛋白H3.1 mRNA不会以poly（a）尾巴结束 相反，他们在3英尺的末端具有茎环结构。茎环结合蛋白（SLBP）附着在茎上 经典组蛋白mRNA进行3'SCORACESS所需的循环RNA结构。以前我们发现 砷暴露下调SLBP水平，使规范组蛋白H3.1 mRNA获得poly（a） 尾巴。 H3.1 mRNA的多腺苷酸化似乎是致癌的，因为它诱导了转录放松管制， 细胞周期停滞和基因组不稳定性以及制备的锚固无关细胞生长和肿瘤 裸鼠的形成。这些影响可能是由于变异组蛋白H3.3组装的破坏而产生的， 因为全基因组组蛋白图显示H3.1 mRNA的聚腺苷酸化损害了H3.3 在转录，细胞身份和异染色质扩散的关键位置组装。 H3.3播放 在转录，有效的DNA损伤修复，适当的染色体分离和 发展。 H3.3的敲低模仿H3.3组装的破坏会诱导细胞转化。 此外，H3.3突变体与各种癌症有关，强调了H3.3的重要性 致癌作用。基于这些观察结果，我们假设H3.3组装的破坏导致 从规范组蛋白H3.1 mRNA的聚腺苷酸化是砷诱导的重要贡献者 致癌作用。为了检验该假设，我们将确定多腺苷酸化的机制 规范组蛋白H3.1 mRNA破坏AIM 1中变体H3.3的组装，确定是否有缺陷 H3.3组装负责砷诱导的异常转录，细胞周期停滞以及基因组 AIM 2中的不稳定性，并确定砷诱导的细胞中H3.3组装破坏的作用 转换并探索AIM 3中的砷暴露是否破坏了体内的H3.3组装。 这些研究的创新在于有可能揭示H3.3组装的破坏作为一种新机制 砷诱导的致癌作用。