1
|
Bedi K, Magnuson B, Narayanan IV, McShane A, Ashaka M, Paulsen MT, Wilson TE, Ljungman M. Isoform and pathway-specific regulation of post-transcriptional RNA processing in human cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.12.598705. [PMID: 38915566 PMCID: PMC11195214 DOI: 10.1101/2024.06.12.598705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Steady-state levels of RNA transcripts are controlled by their rates of synthesis and degradation. Here we used nascent RNA Bru-seq and BruChase-seq to profile RNA dynamics across 16 human cell lines as part of ENCODE4 Deeply Profiled Cell Lines collection. We show that RNA turnover dynamics differ widely between transcripts of different genes and between different classes of RNA. Gene set enrichment analysis (GSEA) revealed that transcripts encoding proteins belonging to the same pathway often show similar turnover dynamics. Furthermore, transcript isoforms show distinct dynamics suggesting that RNA turnover is important in regulating mRNA isoform choice. Finally, splicing across newly made transcripts appears to be cooperative with either all or none type splicing. These data sets generated as part of ENCODE4 illustrate the intricate and coordinated regulation of RNA dynamics in controlling gene expression to allow for the precise coordination of cellular functions.
Collapse
Affiliation(s)
- Karan Bedi
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
- Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Brian Magnuson
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pathology and Department of Human Genetics, University of Michigan Medical School, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Ariel McShane
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mario Ashaka
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michelle T Paulsen
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas E Wilson
- Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Pathology and Department of Human Genetics, University of Michigan Medical School, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mats Ljungman
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
- Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
2
|
Melnick AF, Mullin C, Lin K, McCarter AC, Liang S, Liu YE, Wang Q, Jerome NA, Choe E, Kunnath N, Bodanapu G, Akter F, Magnuson B, Kumar S, Lombard DB, Muntean AG, Ljungman M, Sekiguchi J, Ryan RJH, Chiang MY. Cdc73 protects Notch-induced T-cell leukemia cells from DNA damage and mitochondrial stress. Blood 2023; 142:2159-2174. [PMID: 37616559 PMCID: PMC10733839 DOI: 10.1182/blood.2023020144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/13/2023] [Accepted: 07/31/2023] [Indexed: 08/26/2023] Open
Abstract
ABSTRACT Activated Notch signaling is highly prevalent in T-cell acute lymphoblastic leukemia (T-ALL), but pan-Notch inhibitors showed excessive toxicity in clinical trials. To find alternative ways to target Notch signals, we investigated cell division cycle 73 (Cdc73), which is a Notch cofactor and key component of the RNA polymerase-associated transcriptional machinery, an emerging target in T-ALL. Although we confirmed previous work that CDC73 interacts with NOTCH1, we also found that the interaction in T-ALL was context-dependent and facilitated by the transcription factor ETS1. Using mouse models, we showed that Cdc73 is important for Notch-induced T-cell development and T-ALL maintenance. Mechanistically, chromatin and nascent gene expression profiling showed that Cdc73 intersects with Ets1 and Notch at chromatin within enhancers to activate expression of known T-ALL oncogenes through its enhancer functions. Cdc73 also intersects with these factors within promoters to activate transcription of genes that are important for DNA repair and oxidative phosphorylation through its gene body functions. Consistently, Cdc73 deletion induced DNA damage and apoptosis and impaired mitochondrial function. The CDC73-induced DNA repair expression program co-opted by NOTCH1 is more highly expressed in T-ALL than in any other cancer. These data suggest that Cdc73 might induce a gene expression program that was eventually intersected and hijacked by oncogenic Notch to augment proliferation and mitigate the genotoxic and metabolic stresses of elevated Notch signaling. Our report supports studying factors such as CDC73 that intersect with Notch to derive a basic scientific understanding on how to combat Notch-dependent cancers without directly targeting the Notch complex.
Collapse
Affiliation(s)
- Ashley F. Melnick
- Cellular and Molecular Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
| | - Carea Mullin
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, MI
| | - Karena Lin
- Cellular and Molecular Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
| | - Anna C. McCarter
- Cellular and Molecular Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA
| | - Shannon Liang
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA
| | - Yiran E. Liu
- Cancer Biology Program, Stanford University, Stanford, CA
| | - Qing Wang
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, MI
| | - Nicole A. Jerome
- Cancer Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
| | - Elizabeth Choe
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI
| | - Nicholas Kunnath
- Center for Healthcare Outcomes and Policy, University of Michigan School of Medicine, Ann Arbor, MI
| | - Geethika Bodanapu
- School of Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA
| | - Fatema Akter
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA
| | - Brian Magnuson
- Michigan Center for Translational Pathology, University of Michigan School of Medicine, Ann Arbor, MI
| | - Surinder Kumar
- Department of Pathology and Laboratory Medicine and Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL
| | - David B. Lombard
- Department of Pathology and Laboratory Medicine and Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL
| | - Andrew G. Muntean
- Cellular and Molecular Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
- Department of Pathology, University of Michigan, Ann Arbor, MI
| | - Mats Ljungman
- Cellular and Molecular Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
- Department of Radiology Oncology, University of Michigan School of Medicine, Ann Arbor, MI
| | - JoAnn Sekiguchi
- Cancer Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
- Department of Human Genetics, University of Michigan School of Medicine, Ann Arbor, MI
| | - Russell J. H. Ryan
- Cellular and Molecular Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
- Cancer Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
- Department of Pathology, University of Michigan, Ann Arbor, MI
| | - Mark Y. Chiang
- Cellular and Molecular Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, MI
- Cancer Biology Program, University of Michigan School of Medicine, Ann Arbor, MI
| |
Collapse
|
3
|
Liakos A, Synacheri AC, Konstantopoulos D, Stefos G, Lavigne M, Fousteri M. Enhanced frequency of transcription pre-initiation complexes assembly after exposure to UV irradiation results in increased repair activity and reduced probabilities for mutagenesis. Nucleic Acids Res 2023; 51:8575-8586. [PMID: 37470822 PMCID: PMC10484669 DOI: 10.1093/nar/gkad593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/24/2023] [Accepted: 07/04/2023] [Indexed: 07/21/2023] Open
Abstract
In addition to being essential for gene expression, transcription is crucial for the maintenance of genome integrity. Here, we undertook a systematic approach, to monitor the assembly kinetics of the pre-initiating RNA Polymerase (Pol) II at promoters at steady state and different stages during recovery from UV irradiation-stress, when pre-initiation and initiation steps have been suggested to be transiently shut down. Taking advantage of the reversible dissociation of pre-initiating Pol II after high salt treatment, we found that de novo recruitment of the available Pol II molecules at active promoters not only persists upon UV at all times tested but occurs significantly faster in the early phase of recovery (2 h) than in unexposed human fibroblasts at the majority of active genes. Our method unveiled groups of genes with significantly different pre-initiation complex (PIC) assembly dynamics after UV that present distinct rates of UV-related mutational signatures in melanoma tumours, providing functional relevance to the importance of keeping transcription initiation active during UV recovery. Our findings uncover novel mechanistic insights further detailing the multilayered transcriptional response to genotoxic stress and link PIC assembly dynamics after exposure to genotoxins with cancer mutational landscapes.
Collapse
Affiliation(s)
- Anastasios Liakos
- Institute for Fundamental Biomedical Research, BSRC “Alexander Fleming”, 34 Fleming st., Vari 16672, Greece
| | - Anna-Chloe Synacheri
- Institute for Fundamental Biomedical Research, BSRC “Alexander Fleming”, 34 Fleming st., Vari 16672, Greece
| | - Dimitris Konstantopoulos
- Institute for Fundamental Biomedical Research, BSRC “Alexander Fleming”, 34 Fleming st., Vari 16672, Greece
| | - Georgios C Stefos
- Institute for Fundamental Biomedical Research, BSRC “Alexander Fleming”, 34 Fleming st., Vari 16672, Greece
| | - Matthieu D Lavigne
- Institute for Fundamental Biomedical Research, BSRC “Alexander Fleming”, 34 Fleming st., Vari 16672, Greece
| | - Maria Fousteri
- Institute for Fundamental Biomedical Research, BSRC “Alexander Fleming”, 34 Fleming st., Vari 16672, Greece
| |
Collapse
|
4
|
Fan K, Pfister E, Weng Z. Toward a comprehensive catalog of regulatory elements. Hum Genet 2023; 142:1091-1111. [PMID: 36935423 DOI: 10.1007/s00439-023-02519-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 01/03/2023] [Indexed: 03/21/2023]
Abstract
Regulatory elements are the genomic regions that interact with transcription factors to control cell-type-specific gene expression in different cellular environments. A precise and complete catalog of functional elements encoded by the human genome is key to understanding mammalian gene regulation. Here, we review the current state of regulatory element annotation. We first provide an overview of assays for characterizing functional elements, including genome, epigenome, transcriptome, three-dimensional chromatin interaction, and functional validation assays. We then discuss computational methods for defining regulatory elements, including peak-calling and other statistical modeling methods. Finally, we introduce several high-quality lists of regulatory element annotations and suggest potential future directions.
Collapse
Affiliation(s)
- Kaili Fan
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, 368 Plantation Street, ASC5-1069, Worcester, MA, 01605, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Edith Pfister
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, 368 Plantation Street, ASC5-1069, Worcester, MA, 01605, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, 368 Plantation Street, ASC5-1069, Worcester, MA, 01605, USA.
| |
Collapse
|
5
|
Melnick A, Liang S, Liu Y, Wang Q, Dean N, Choe E, Kunnath N, Bodanapu G, Mullin C, Akter F, Lin K, Magnuson B, Kumar S, Lombard DB, Muntean AG, Ljungman M, Sekiguchi J, Ryan RJH, Chiang MY. Cdc73 protects Notch-induced T-cell leukemia cells from DNA damage and mitochondrial stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.22.525059. [PMID: 36711472 PMCID: PMC9882378 DOI: 10.1101/2023.01.22.525059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Activated Notch signaling is highly prevalent in T-cell acute lymphoblastic leukemia (T-ALL) but pan-Notch inhibitors were toxic in clinical trials. To find alternative ways to target Notch signals, we investigated Cell division cycle 73 (Cdc73), which is a Notch cofactor and component of transcriptional machinery, a potential target in T-ALL. While we confirmed previous work that CDC73 interacts with NOTCH1, we also found that the interaction in T-ALL was context-dependent and facilitated by the lymphoid transcription factor ETS1. Using mouse models, we showed that Cdc73 is important for Notch-induced T-cell development and T-ALL maintenance. Mechanistically, Cdc73, Ets1, and Notch intersect chromatin at promoters and enhancers to activate oncogenes and genes that are important for DNA repair and oxidative phosphorylation. Consistently, Cdc73 deletion in T-ALL cells induced DNA damage and impaired mitochondrial function. Our data suggests that Cdc73 might promote a gene expression program that was eventually intersected by Notch to mitigate the genotoxic and metabolic stresses of elevated Notch signaling. We also provide mechanistic support for testing inhibitors of DNA repair, oxidative phosphorylation, and transcriptional machinery. Inhibiting pathways like Cdc73 that intersect with Notch at chromatin might constitute a strategy to weaken Notch signals without directly targeting the Notch complex.
Collapse
|
6
|
Interplay Between the Histone Variant H2A.Z and the Epigenome in Pancreatic Cancer. Arch Med Res 2022; 53:840-858. [PMID: 36470770 DOI: 10.1016/j.arcmed.2022.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/25/2022] [Accepted: 11/18/2022] [Indexed: 12/03/2022]
Abstract
BACKGROUND The oncogenic process is orchestrated by a complex network of chromatin remodeling elements that shape the cancer epigenome. Histone variant H2A.Z regulates DNA control elements such as promoters and enhancers in different types of cancer; however, the interplay between H2A.Z and the pancreatic cancer epigenome is unknown. OBJECTIVE This study analyzed the role of H2A.Z in different DNA regulatory elements. METHODS We performed Chromatin Immunoprecipitation Sequencing assays (ChiP-seq) with total H2A.Z and acetylated H2A.Z (acH2A.Z) antibodies and analyzed published data from ChIP-seq, RNA-seq, bromouridine labeling-UV and sequencing (BruUV-seq), Hi-C and ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) in the pancreatic cancer cell line PANC-1. RESULTS The results indicate that total H2A.Z facilitates the recruitment of RNA polymerase II and transcription factors at promoters and enhancers allowing the expression of pro-oncogenic genes. Interestingly, we demonstrated that H2A.Z is enriched in super-enhancers (SEs) contributing to the transcriptional activation of key genes implicated in tumor development. Importantly, we established that H2A.Z contributes to the three-dimensional (3D) genome organization of pancreatic cancer and that it is a component of the Topological Associated Domains (TADs) boundaries in PANC-1 and that total H2A.Z and acH2A.Z are associated with A and B compartments, respectively. CONCLUSIONS H2A.Z participates in the biology and development of pancreatic cancer by generating a pro-oncogenic transcriptome through its posttranslational modifications, interactions with different partners, and regulatory elements, contributing to the oncogenic 3D genome organization. These data allow us to understand the molecular mechanisms that promote an oncogenic transcriptome in pancreatic cancer mediated by H2A.Z.
Collapse
|
7
|
Zheng M, Lin Y, Wang W, Zhao Y, Bao X. Application of nucleoside or nucleotide analogues in RNA dynamics and RNA-binding protein analysis. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1722. [PMID: 35218164 DOI: 10.1002/wrna.1722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 01/07/2022] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Cellular RNAs undergo dynamic changes during RNA biological processes, which are tightly orchestrated by RNA-binding proteins (RBPs). Yet, the investigation of RNA dynamics is hurdled by highly abundant steady-state RNAs, which make the signals of dynamic RNAs less detectable. Notably, the exert of nucleoside or nucleotide analogue-based RNA technologies has provided a remarkable platform for RNA dynamics research, revealing diverse unnoticed features in RNA metabolism. In this review, we focus on the application of two types of analogue-based RNA sequencing, antigen-/antibody- and click chemistry-based methodologies, and summarize the RNA dynamics features revealed. Moreover, we discuss emerging single-cell newly transcribed RNA sequencing methodologies based on nucleoside analogue labeling, which provides novel insights into RNA dynamics regulation at single-cell resolution. On the other hand, we also emphasize the identification of RBPs that interact with polyA, non-polyA RNAs, or newly transcribed RNAs and also their associated RNA-binding domains at genomewide level through ultraviolet crosslinking and mass spectrometry in different contexts. We anticipated that further modification and development of these analogue-based RNA and RBP capture technologies will aid in obtaining an unprecedented understanding of RNA biology. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry RNA Methods > RNA Analyses in Cells.
Collapse
Affiliation(s)
- Meifeng Zheng
- Center for Cell Lineage and Development, CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, GIBH-HKU Guangdong-Hong Kong Stem Cell and Regenerative Medicine Research Centre, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yingying Lin
- Center for Cell Lineage and Development, CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, GIBH-HKU Guangdong-Hong Kong Stem Cell and Regenerative Medicine Research Centre, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- The Center for Infection and Immunity Study, School of Medicine, Sun Yat-sen University, Guangming Science City, Shenzhen, China
| | - Wei Wang
- Center for Biosafety, Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| | - Yu Zhao
- Molecular Cancer Research Center, School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Xichen Bao
- Center for Cell Lineage and Development, CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, GIBH-HKU Guangdong-Hong Kong Stem Cell and Regenerative Medicine Research Centre, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Center for Cell Lineage and Atlas, Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| |
Collapse
|
8
|
Ljungman M. Transcription and genome integrity. DNA Repair (Amst) 2022; 118:103373. [PMID: 35914488 DOI: 10.1016/j.dnarep.2022.103373] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/16/2022] [Accepted: 07/17/2022] [Indexed: 11/03/2022]
Abstract
Transcription can cause genome instability by promoting R-loop formation but also act as a mutation-suppressing machinery by sensing of DNA lesions leading to the activation of DNA damage signaling and transcription-coupled repair. Recovery of RNA synthesis following the resolution of repair of transcription-blocking lesions is critical to avoid apoptosis and several new factors involved in this process have recently been identified. Some DNA repair proteins are recruited to initiating RNA polymerases and this may expediate the recruitment of other factors that participate in the repair of transcription-blocking DNA lesions. Recent studies have shown that transcription of protein-coding genes does not always give rise to spliced transcripts, opening the possibility that cells may use the transcription machinery in a splicing-uncoupled manner for other purposes including surveillance of the transcribed genome.
Collapse
Affiliation(s)
- Mats Ljungman
- Departments of Radiation Oncology and Environmental Health Sciences, Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
9
|
A comparison of experimental assays and analytical methods for genome-wide identification of active enhancers. Nat Biotechnol 2022; 40:1056-1065. [PMID: 35177836 PMCID: PMC9288987 DOI: 10.1038/s41587-022-01211-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/06/2022] [Indexed: 01/15/2023]
Abstract
Mounting evidence supports the idea that transcriptional patterns serve as more specific identifiers of active enhancers than histone marks; however, the optimal strategy to identify active enhancers both experimentally and computationally has not been determined. Here, we compared 13 genome-wide RNA sequencing assays in K562 cells and showed that the nuclear run-on followed by cap-selection assay (GRO/PRO-cap) has advantages in eRNA detection and active enhancer identification. We also introduced a tool, Peak Identifier for Nascent Transcript Starts (PINTS), to identify active promoters and enhancers genome-wide and pinpoint the precise location of the 5′ transcription start sites. Finally, we compiled a comprehensive enhancer candidate compendium based on the detected eRNA TSSs available in 120 cell and tissue types that can be accessed at https://pints.yulab.org. With the knowledge of the best available assays and pipelines, this large-scale annotation of candidate enhancers will pave the way for selection and characterization of their functions in a time- and labor-efficient manner in the future.
Collapse
|
10
|
Moore JE, Zhang XO, Elhajjajy SI, Fan K, Pratt HE, Reese F, Mortazavi A, Weng Z. Integration of high-resolution promoter profiling assays reveals novel, cell type-specific transcription start sites across 115 human cell and tissue types. Genome Res 2021; 32:389-402. [PMID: 34949670 PMCID: PMC8805725 DOI: 10.1101/gr.275723.121] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 12/19/2021] [Indexed: 12/02/2022]
Abstract
Accurate transcription start site (TSS) annotations are essential for understanding transcriptional regulation and its role in human disease. Gene collections such as GENCODE contain annotations for tens of thousands of TSSs, but not all of these annotations are experimentally validated nor do they contain information on cell type–specific usage. Therefore, we sought to generate a collection of experimentally validated TSSs by integrating RNA Annotation and Mapping of Promoters for the Analysis of Gene Expression (RAMPAGE) data from 115 cell and tissue types, which resulted in a collection of approximately 50 thousand representative RAMPAGE peaks. These peaks are primarily proximal to GENCODE-annotated TSSs and are concordant with other transcription assays. Because RAMPAGE uses paired-end reads, we were then able to connect peaks to transcripts by analyzing the genomic positions of the 3′ ends of read mates. Using this paired-end information, we classified the vast majority (37 thousand) of our RAMPAGE peaks as verified TSSs, updating TSS annotations for 20% of GENCODE genes. We also found that these updated TSS annotations are supported by epigenomic and other transcriptomic data sets. To show the utility of this RAMPAGE rPeak collection, we intersected it with the NHGRI/EBI genome-wide association study (GWAS) catalog and identified new candidate GWAS genes. Overall, our work shows the importance of integrating experimental data to further refine TSS annotations and provides a valuable resource for the biological community.
Collapse
Affiliation(s)
| | | | | | - Kaili Fan
- University of Massachusetts Chan Medical School
| | | | | | | | - Zhiping Weng
- University of Massachusetts Chan Medical School;
| |
Collapse
|
11
|
Adhikary S, Roy S, Chacon J, Gadad SS, Das C. Implications of Enhancer Transcription and eRNAs in Cancer. Cancer Res 2021; 81:4174-4182. [PMID: 34016622 DOI: 10.1158/0008-5472.can-20-4010] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 05/03/2021] [Accepted: 05/19/2021] [Indexed: 11/16/2022]
Abstract
Despite extensive progress in developing anticancer therapies, therapy resistance remains a major challenge that promotes disease relapse. The changes that lead to therapy resistance can be intrinsically present or may be initiated during treatment. Genetic and epigenetic heterogeneity in tumors make it more challenging to deal with therapy resistance. Recent advances in genome-wide analyses have revealed that the deregulation of distal gene regulatory elements, such as enhancers, appears in several pathophysiological conditions, including cancer. Beyond the conventional function of enhancers in recruiting transcription factors to gene promoters, enhancer elements are also transcribed into noncoding RNAs known as enhancer RNAs (eRNA). Accumulating evidence suggests that uncontrolled enhancer activity with aberrant eRNA expression promotes oncogenesis. Interestingly, tissue-specific, transcribed eRNAs from active enhancers can serve as potential therapeutic targets or biomarkers in several cancer types. This review provides a comprehensive overview of the mechanisms of enhancer transcription and eRNAs as well as their potential roles in cancer and drug resistance.
Collapse
Affiliation(s)
- Santanu Adhikary
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India.,Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Siddhartha Roy
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Jessica Chacon
- Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas
| | - Shrikanth S Gadad
- Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas. .,Center of Emphasis in Cancer, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas.,Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center El Paso, El Paso, Texas.,Cecil H. and Ida Green Center for Reproductive Biology Sciences, Department of Obstetrics and Gynaecology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Chandrima Das
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India. .,Homi Bhaba National Institute, Mumbai, Maharashtra, India
| |
Collapse
|
12
|
Tan Y, Li Y, Tang F. Oncogenic seRNA functional activation: a novel mechanism of tumorigenesis. Mol Cancer 2020; 19:74. [PMID: 32278350 PMCID: PMC7149907 DOI: 10.1186/s12943-020-01195-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 03/30/2020] [Indexed: 02/06/2023] Open
Abstract
seRNA is a noncoding RNA (ncRNA) transcribed from active super-enhancer (SE), through which SE exerts biological functions and participates in various physiological and pathological processes. seRNA recruits cofactor, RNA polymerase II and mediator to constitute and stabilize chromatin loop SE and promoter region, which regulates target genes transcription. In tumorigenesis, DNA insertion, deletion, translocation, focal amplification and carcinogen factor mediate oncogenic SE generation, meanwhile, oncogenic SE transcribes into tumor-related seRNA, termed as oncogenic seRNA. Oncogenic seRNA participates in tumorigenesis through activating various signal-pathways. The recent reports showed that oncogenic seRNA implicates in a widespread range of cytopathological processes in cancer progression including cell proliferation, apoptosis, autophagy, epithelial-mesenchymal transition, extracellular matrix stiffness and angiogenesis. In this article, we comprehensively summarized seRNA’s characteristics and functions, and emphatically introduced inducible formation of oncogenic seRNA and its functional mechanisms. Lastly, some research strategies on oncogenic seRNA were introduced, and the perspectives on cancer therapy that targets oncogenic seRNA were also discussed.
Collapse
Affiliation(s)
- Yuan Tan
- Department of Clinical Laboratory and Hunan Key Laboratory of Oncotarget gene, Hunan Cancer Hospital & The affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, China
| | - Yuejin Li
- Department of Clinical Laboratory and Hunan Key Laboratory of Oncotarget gene, Hunan Cancer Hospital & The affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, China
| | - Faqing Tang
- Department of Clinical Laboratory and Hunan Key Laboratory of Oncotarget gene, Hunan Cancer Hospital & The affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, China.
| |
Collapse
|
13
|
Bedi K, Paulsen MT, Wilson TE, Ljungman M. Characterization of novel primary miRNA transcription units in human cells using Bru-seq nascent RNA sequencing. NAR Genom Bioinform 2020; 2:lqz014. [PMID: 31709421 PMCID: PMC6824518 DOI: 10.1093/nargab/lqz014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/07/2019] [Accepted: 10/26/2019] [Indexed: 12/12/2022] Open
Abstract
MicroRNAs (miRNAs) are key contributors to gene regulatory networks. Because miRNAs are processed from RNA polymerase II transcripts, insight into miRNA regulation requires a comprehensive understanding of the regulation of primary miRNA transcripts. We used Bru-seq nascent RNA sequencing and hidden Markov model segmentation to map primary miRNA transcription units (TUs) across 32 human cell lines, allowing us to describe TUs encompassing 1443 miRNAs from miRBase and 438 from MirGeneDB. We identified TUs for 61 miRNAs with an unknown CAGE TSS signal for MirGeneDB miRNAs. Many primary transcripts containing miRNA sequences failed to generate mature miRNAs, suggesting that miRNA biosynthesis is under both transcriptional and post-transcriptional control. In addition to constitutive and cell-type specific TU expression regulated by differential promoter usage, miRNA synthesis can be regulated by transcription past polyadenylation sites (transcriptional read through) and promoter divergent transcription (PROMPTs). We identified 197 miRNA TUs with novel promoters, 97 with transcriptional read-throughs and 3 miRNA TUs that resemble PROMPTs in at least one cell line. The miRNA TU annotation data resource described here reveals a greater complexity in miRNA regulation than previously known and provides a framework for identifying cell-type specific differences in miRNA transcription in cancer and cell transition states.
Collapse
Affiliation(s)
- Karan Bedi
- Department of Radiation Oncology, Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michelle T Paulsen
- Department of Radiation Oncology, Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas E Wilson
- Department of Pathology and Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Mats Ljungman
- Department of Radiation Oncology, Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
14
|
Liakos A, Konstantopoulos D, Lavigne MD, Fousteri M. Continuous transcription initiation guarantees robust repair of all transcribed genes and regulatory regions. Nat Commun 2020; 11:916. [PMID: 32060325 PMCID: PMC7021815 DOI: 10.1038/s41467-020-14566-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 01/16/2020] [Indexed: 02/07/2023] Open
Abstract
Inhibition of transcription caused by DNA damage-impaired RNA polymerase II (Pol II) elongation conceals a local increase in de novo transcription, slowly progressing from Transcription Start Sites (TSSs) to gene ends. Although associated with accelerated repair of Pol II-encountered lesions and limited mutagenesis, it is still unclear how this mechanism is maintained during genotoxic stress-recovery. Here we uncover a widespread gain in chromatin accessibility and preservation of the active H3K27ac mark after UV-irradiation. The concomitant increase in Pol II escape from promoter-proximal pause (PPP) sites of most active genes, PROMPTs and enhancer RNAs favors unrestrained initiation, as evidenced by the synthesis of nascent RNAs including start RNAs. Accordingly, drug-inhibition of PPP-release replenishes levels of pre-initiating Pol II at TSSs after UV. Our data show that such continuous engagement of Pol II molecules ensures maximal transcription-driven repair throughout expressed genes and regulatory loci. Importantly, revealing this unanticipated regulatory layer of UV-response provides physiological relevant traction to the emerging concept that Pol II initiation rate is determined by pause-release dynamics. A transcription-driven cellular response is activated upon UV stress. Here the authors reveal mechanistic insights into the regulatory process affecting transcription and chromatin dynamics, showing how maintaining Pol II firing safeguards the integrity of cells’ transcriptome
Collapse
Affiliation(s)
- Anastasios Liakos
- Institute for Fundamental Biomedical Research, BSRC 'Alexander Fleming', 34 Fleming st., 16672, Vari, Athens, Greece.,Department of Biology, School of Science, National & Kapodistrian University of Athens, Athens, Greece
| | - Dimitris Konstantopoulos
- Institute for Fundamental Biomedical Research, BSRC 'Alexander Fleming', 34 Fleming st., 16672, Vari, Athens, Greece.,Department of Biology, University of Crete, 70013, Herakleion, Greece
| | - Matthieu D Lavigne
- Institute for Fundamental Biomedical Research, BSRC 'Alexander Fleming', 34 Fleming st., 16672, Vari, Athens, Greece.
| | - Maria Fousteri
- Institute for Fundamental Biomedical Research, BSRC 'Alexander Fleming', 34 Fleming st., 16672, Vari, Athens, Greece.
| |
Collapse
|
15
|
Rodrigues DF, Costa VM, Silvestre R, Bastos ML, Carvalho F. Methods for the analysis of transcriptome dynamics. Toxicol Res (Camb) 2019; 8:597-612. [PMID: 31588338 PMCID: PMC6764467 DOI: 10.1039/c9tx00088g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 07/18/2019] [Indexed: 12/13/2022] Open
Abstract
The transcriptome is the complete set of transcripts in a cell or tissue and includes ribosomal RNA (rRNA), messenger RNA (mRNA), transfer RNA (tRNA), and regulatory noncoding RNA. At steady-state, the transcriptome results from a compensatory variation of the transcription and decay rate to maintain the RNA concentration constant. RNA transcription constitutes the first stage in gene expression, and thus is a major and primary mode of gene expression control. Nevertheless, regulation of RNA decay is also a key factor in gene expression control, involving either selective RNA stabilization or enhanced degradation. Transcriptome analysis allows the identification of gene expression alterations, providing new insights regarding the pathways and mechanisms involved in physiological and pathological processes. Upon perturbation of cell homeostasis, rapid changes in gene expression are required to adapt to new conditions. Thus, to better understand the regulatory mechanisms associated with gene expression alterations, it is vital to acknowledge the relative contribution of RNA synthesis and decay to the transcriptome. To the toxicology field, the study of gene expression regulation mechanisms can help identify the early and mechanistic relevant cellular events associated with a particular response. This review aims to provide a critical comparison of the available methods used to analyze the contribution of RNA transcription and decay to gene expression dynamics. Notwithstanding, an integration of the data obtained is necessary to understand the entire repercussions of gene transcription changes at a system-level. Thus, a brief overview of the methods available for the integration and analysis of the data obtained from transcriptome analysis will also be provided.
Collapse
Affiliation(s)
- Daniela F Rodrigues
- UCIBIO , REQUIMTE , Laboratory of Toxicology , Faculty of Pharmacy , University of Porto , Rua Jorge Viterbo Ferreira , 228 , 4050-313 , Porto , Portugal . ;
| | - Vera M Costa
- UCIBIO , REQUIMTE , Laboratory of Toxicology , Faculty of Pharmacy , University of Porto , Rua Jorge Viterbo Ferreira , 228 , 4050-313 , Porto , Portugal . ;
| | - Ricardo Silvestre
- Life and Health Sciences Research Institute (ICVS) , School of Medicine , University of Minho , Campus de Gualtar , 4710-057 , Braga , Portugal
- ICVS/3B's-PT Government Associate Laboratory , Braga/Guimarães , Campus de Gualtar , 4710-057 , Braga , Portugal
| | - Maria L Bastos
- UCIBIO , REQUIMTE , Laboratory of Toxicology , Faculty of Pharmacy , University of Porto , Rua Jorge Viterbo Ferreira , 228 , 4050-313 , Porto , Portugal . ;
| | - Félix Carvalho
- UCIBIO , REQUIMTE , Laboratory of Toxicology , Faculty of Pharmacy , University of Porto , Rua Jorge Viterbo Ferreira , 228 , 4050-313 , Porto , Portugal . ;
| |
Collapse
|
16
|
|
17
|
Oshima G, Poli EC, Bolt MJ, Chlenski A, Forde M, Jutzy JMS, Biyani N, Posner MC, Pitroda SP, Weichselbaum RR, Khodarev NN. DNA Methylation Controls Metastasis-Suppressive 14q32-Encoded miRNAs. Cancer Res 2019; 79:650-662. [PMID: 30538122 DOI: 10.1158/0008-5472.can-18-0692] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 09/07/2018] [Accepted: 12/07/2018] [Indexed: 12/12/2022]
Abstract
Expression of 14q32-encoded miRNAs is a favorable prognostic factor in patients with metastatic cancer. In this study, we used genomic inhibition of DNA methylation through disruption of DNA methyltransferases DNMT1 and DNMT3B and pharmacologic inhibition with 5-Aza-2'-deoxycytidine (5-Aza-dC, decitabine) to demonstrate that DNA methylation predominantly regulates expression of metastasis-suppressive miRNAs in the 14q32 cluster. DNA demethylation facilitated CCCTC-binding factor (CTCF) recruitment to the maternally expressed gene 3 differentially methylated region (MEG3-DMR), which acts as a cis-regulatory element for 14q32 miRNA expression. 5-Aza-dC activated demethylation of the MEG3-DMR and expression of 14q32 miRNAs, which suppressed adhesion, invasion, and migration (AIM) properties of metastatic tumor cells. Cancer cells with MEG3-DMR hypomethylation exhibited constitutive expression of 14q32 miRNAs and resistance to 5-Aza-dC-induced suppression of AIM. Expression of methylation-dependent 14q32 miRNAs suppressed metastatic colonization in preclinical models of lung and liver metastasis and correlated with improved clinical outcomes in patients with metastatic cancer. These findings implicate epigenetic modification via DNA methylation in the regulation of metastatic propensity through miRNA networks and identify a previously unrecognized action of decitabine on the activation of metastasis-suppressive miRNAs. SIGNIFICANCE: This study investigates epigenetic regulation of metastasis-suppressive miRNAs and the effect on metastasis.
Collapse
Affiliation(s)
- Go Oshima
- Department of Surgery, The University of Chicago, Chicago, Illinois
| | - Elizabeth C Poli
- Department of Surgery, The University of Chicago, Chicago, Illinois
| | - Michael J Bolt
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois
- Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois
| | | | - Martin Forde
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois
- Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois
| | - Jessica M S Jutzy
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois
| | - Neha Biyani
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois
- Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois
| | | | - Sean P Pitroda
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois
- Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois
| | - Ralph R Weichselbaum
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois.
- Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois
| | - Nikolai N Khodarev
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois.
- Ludwig Center for Metastasis Research, The University of Chicago, Chicago, Illinois
| |
Collapse
|
18
|
Liu F. Enhancer-derived RNA: A Primer. GENOMICS PROTEOMICS & BIOINFORMATICS 2017; 15:196-200. [PMID: 28533025 PMCID: PMC5487531 DOI: 10.1016/j.gpb.2016.12.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/16/2016] [Accepted: 12/26/2016] [Indexed: 12/16/2022]
Abstract
Enhancer-derived RNAs (eRNAs) are a group of RNAs transcribed by RNA polymerase II from the domain of transcription enhancers, a major type of cis-regulatory elements in the genome. The correlation between eRNA production and enhancer activity has stimulated studies on the potential role of eRNAs in transcriptional regulation. Additionally, eRNA has also served as a marker for global identification of enhancers. Here I review the brief history and fascinating properties of eRNAs.
Collapse
Affiliation(s)
- Feng Liu
- National Research Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| |
Collapse
|
19
|
Frank SB, Berger PL, Ljungman M, Miranti CK. Human prostate luminal cell differentiation requires NOTCH3 induction by p38-MAPK and MYC. J Cell Sci 2017; 130:1952-1964. [PMID: 28446540 DOI: 10.1242/jcs.197152] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 04/17/2017] [Indexed: 12/14/2022] Open
Abstract
Many pathways dysregulated in prostate cancer are also involved in epithelial differentiation. To better understand prostate tumor initiation, we sought to investigate specific genes and mechanisms required for normal basal to luminal cell differentiation. Utilizing human prostate basal epithelial cells and an in vitro differentiation model, we tested the hypothesis that regulation of NOTCH3 by the p38 MAPK family (hereafter p38-MAPK), via MYC, is required for luminal differentiation. Inhibition (SB202190 and BIRB796) or knockdown of p38α (also known as MAPK14) and/or p38δ (also known as MAPK13) prevented proper differentiation. Additionally, treatment with a γ-secretase inhibitor (RO4929097) or knockdown of NOTCH1 and/or NOTCH3 greatly impaired differentiation and caused luminal cell death. Constitutive p38-MAPK activation through MKK6(CA) increased NOTCH3 (but not NOTCH1) mRNA and protein levels, which was diminished upon MYC inhibition (10058-F4 and JQ1) or knockdown. Furthermore, we validated two NOTCH3 enhancer elements through a combination of enhancer (e)RNA detection (BruUV-seq) and luciferase reporter assays. Finally, we found that the NOTCH3 mRNA half-life increased during differentiation or upon acute p38-MAPK activation. These results reveal a new connection between p38-MAPK, MYC and NOTCH signaling, demonstrate two mechanisms of NOTCH3 regulation and provide evidence for NOTCH3 involvement in prostate luminal cell differentiation.
Collapse
Affiliation(s)
- Sander B Frank
- Laboratory of Integrin Signaling and Tumorigenesis, Van Andel Research Institute, Grand Rapids, MI 49503, USA.,Genetics Program, Michigan State University, East Lansing, MI 48824, USA.,Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, Tucson, AZ 85724, USA
| | - Penny L Berger
- Laboratory of Integrin Signaling and Tumorigenesis, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Mats Ljungman
- Translational Oncology Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Cindy K Miranti
- Laboratory of Integrin Signaling and Tumorigenesis, Van Andel Research Institute, Grand Rapids, MI 49503, USA .,Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, Tucson, AZ 85724, USA
| |
Collapse
|
20
|
Transcriptional and post-transcriptional regulation of the ionizing radiation response by ATM and p53. Sci Rep 2017; 7:43598. [PMID: 28256581 PMCID: PMC5335570 DOI: 10.1038/srep43598] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 01/25/2017] [Indexed: 12/19/2022] Open
Abstract
In response to ionizing radiation (IR), cells activate a DNA damage response (DDR) pathway to re-program gene expression. Previous studies using total cellular RNA analyses have shown that the stress kinase ATM and the transcription factor p53 are integral components required for induction of IR-induced gene expression. These studies did not distinguish between changes in RNA synthesis and RNA turnover and did not address the role of enhancer elements in DDR-mediated transcriptional regulation. To determine the contribution of synthesis and degradation of RNA and monitor the activity of enhancer elements following exposure to IR, we used the recently developed Bru-seq, BruChase-seq and BruUV-seq techniques. Our results show that ATM and p53 regulate both RNA synthesis and stability as well as enhancer element activity following exposure to IR. Importantly, many genes in the p53-signaling pathway were coordinately up-regulated by both increased synthesis and RNA stability while down-regulated genes were suppressed either by reduced synthesis or stability. Our study is the first of its kind that independently assessed the effects of ionizing radiation on transcription and post-transcriptional regulation in normal human cells.
Collapse
|
21
|
Evolution of Brain Active Gene Promoters in Human Lineage Towards the Increased Plasticity of Gene Regulation. Mol Neurobiol 2017; 55:1871-1904. [PMID: 28233272 DOI: 10.1007/s12035-017-0427-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 01/26/2017] [Indexed: 01/31/2023]
Abstract
Adaptability to a variety of environmental conditions is a prominent feature of Homo sapiens. We hypothesize that this feature can be explained by evolutionary changes in gene promoters active in the brain prefrontal cortex leading to a more flexible gene regulation network. The genotype-dependent range of gene expression can be broader in humans than in other higher primates. Thus, we searched for specific signatures of evolutionary changes in promoter architectures of multiple hominid genes, including the genes active in human cortical neurons that may indicate an increase of variability of gene expression rather than just changes in the level of expression, such as downregulation or upregulation of the genes. We performed a whole-genome search for genetic-based alterations that may impact gene regulation "flexibility" in a process of hominids evolution, such as (i) CpG dinucleotide content, (ii) predicted nucleosome-DNA dissociation constant, and (iii) predicted affinities for TATA-binding protein (TBP) in gene promoters. We tested all putative promoter regions across the human genome and especially gene promoters in active chromatin state in neurons of prefrontal cortex, the brain region critical for abstract thinking and social and behavioral adaptation. Our data imply that the origin of modern man has been associated with an increase of flexibility of promoter-driven gene regulation in brain. In contrast, after splitting from the ancestral lineages of H. sapiens, the evolution of ape species is characterized by reduced flexibility of gene promoter functioning, underlying reduced variability of the gene expression.
Collapse
|
22
|
Kirkconnell KS, Magnuson B, Paulsen MT, Lu B, Bedi K, Ljungman M. Gene length as a biological timer to establish temporal transcriptional regulation. Cell Cycle 2017; 16:259-270. [PMID: 28055303 DOI: 10.1080/15384101.2016.1234550] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Transcriptional timing is inherently influenced by gene length, thus providing a mechanism for temporal regulation of gene expression. While gene size has been shown to be important for the expression timing of specific genes during early development, whether it plays a role in the timing of other global gene expression programs has not been extensively explored. Here, we investigate the role of gene length during the early transcriptional response of human fibroblasts to serum stimulation. Using the nascent sequencing techniques Bru-seq and BruUV-seq, we identified immediate genome-wide transcriptional changes following serum stimulation that were linked to rapid activation of enhancer elements. We identified 873 significantly induced and 209 significantly repressed genes. Variations in gene size allowed for a large group of genes to be simultaneously activated but produce full-length RNAs at different times. The median length of the group of serum-induced genes was significantly larger than the median length of all expressed genes, housekeeping genes, and serum-repressed genes. These gene length relationships were also observed in corresponding mouse orthologs, suggesting that relative gene size is evolutionarily conserved. The sizes of transcription factor and microRNA genes immediately induced after serum stimulation varied dramatically, setting up a cascade mechanism for temporal expression arising from a single activation event. The retention and expansion of large intronic sequences during evolution have likely played important roles in fine-tuning the temporal expression of target genes in various cellular response programs.
Collapse
Affiliation(s)
- Killeen S Kirkconnell
- a Department of Radiation Oncology , University of Michigan Comprehensive Cancer Center, Translational Oncology Program, and Center for RNA Biomedicine, University of Michigan , Ann Arbor , MI , USA.,b Department of Human Genetics , University of Michigan Medical School , Ann Arbor , MI , USA
| | - Brian Magnuson
- a Department of Radiation Oncology , University of Michigan Comprehensive Cancer Center, Translational Oncology Program, and Center for RNA Biomedicine, University of Michigan , Ann Arbor , MI , USA.,c Department of Environmental Health Sciences , School of Public Health, University of Michigan , Ann Arbor , MI , USA
| | - Michelle T Paulsen
- a Department of Radiation Oncology , University of Michigan Comprehensive Cancer Center, Translational Oncology Program, and Center for RNA Biomedicine, University of Michigan , Ann Arbor , MI , USA
| | - Brian Lu
- a Department of Radiation Oncology , University of Michigan Comprehensive Cancer Center, Translational Oncology Program, and Center for RNA Biomedicine, University of Michigan , Ann Arbor , MI , USA
| | - Karan Bedi
- a Department of Radiation Oncology , University of Michigan Comprehensive Cancer Center, Translational Oncology Program, and Center for RNA Biomedicine, University of Michigan , Ann Arbor , MI , USA
| | - Mats Ljungman
- a Department of Radiation Oncology , University of Michigan Comprehensive Cancer Center, Translational Oncology Program, and Center for RNA Biomedicine, University of Michigan , Ann Arbor , MI , USA.,c Department of Environmental Health Sciences , School of Public Health, University of Michigan , Ann Arbor , MI , USA
| |
Collapse
|
23
|
Li W, Notani D, Rosenfeld MG. Enhancers as non-coding RNA transcription units: recent insights and future perspectives. Nat Rev Genet 2016; 17:207-23. [PMID: 26948815 DOI: 10.1038/nrg.2016.4] [Citation(s) in RCA: 492] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Networks of regulatory enhancers dictate distinct cell identities and cellular responses to diverse signals by instructing precise spatiotemporal patterns of gene expression. However, 35 years after their discovery, enhancer functions and mechanisms remain incompletely understood. Intriguingly, recent evidence suggests that many, if not all, functional enhancers are themselves transcription units, generating non-coding enhancer RNAs. This observation provides a fundamental insight into the inter-regulation between enhancers and promoters, which can both act as transcription units; it also raises crucial questions regarding the potential biological roles of the enhancer transcription process and non-coding enhancer RNAs. Here, we review research progress in this field and discuss several important, unresolved questions regarding the roles and mechanisms of enhancers in gene regulation.
Collapse
Affiliation(s)
- Wenbo Li
- Howard Hughes Medical Institute, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037-0648, USA
| | - Dimple Notani
- Howard Hughes Medical Institute, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037-0648, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92037-0648, USA
| |
Collapse
|