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Scalia P, Williams SJ, Fujita-Yamaguchi Y. Human IGF2 Gene Epigenetic and Transcriptional Regulation: At the Core of Developmental Growth and Tumorigenic Behavior. Biomedicines 2023; 11:1655. [PMID: 37371750 DOI: 10.3390/biomedicines11061655] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Regulation of the human IGF2 gene displays multiple layers of control, which secures a genetically and epigenetically predetermined gene expression pattern throughout embryonal growth and postnatal life. These predominantly nuclear regulatory mechanisms converge on the function of the IGF2-H19 gene cluster on Chromosome 11 and ultimately affect IGF2 gene expression. Deregulation of such control checkpoints leads to the enhancement of IGF2 gene transcription and/or transcript stabilization, ultimately leading to IGF-II peptide overproduction. This type of anomaly is responsible for the effects observed in terms of both abnormal fetal growth and increased cell proliferation, typically observed in pediatric overgrowth syndromes and cancer. We performed a review of relevant experimental work on the mechanisms affecting the human IGF2 gene at the epigenetic, transcriptional and transcript regulatory levels. The result of our work, indeed, provides a wider and diversified scenario for IGF2 gene activation than previously envisioned by shedding new light on its extended regulation. Overall, we focused on the functional integration between the epigenetic and genetic machinery driving its overexpression in overgrowth syndromes and malignancy, independently of the underlying presence of loss of imprinting (LOI). The molecular landscape provided at last strengthens the role of IGF2 in cancer initiation, progression and malignant phenotype maintenance. Finally, this review suggests potential actionable targets for IGF2 gene- and regulatory protein target-degradation therapies.
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Key Words
- (IGF2/H19) IG-DMR, intergenic differentially methylated region
- BWS, Beckwith–Wiedemann syndrome
- CCD, centrally conserved domain
- CNV, copy number variation
- CTCF, CCCTC binding factor
- DMD, differentially methylated domain
- DMR, differentially methylated region
- GOM, gain of methylation
- ICR1, imprinting control region 1
- IGF-II, insulin-like growth factor-2 peptide
- IGF2, insulin-like growth factor 2 gene
- LOI, loss of imprinting
- LOM, loss of methylation
- MOI, maintenance of imprinting
- SRS, Silver Russel Syndrome
- TF: transcription factor
- UPD, uniparental disomy
- WT1, Wilms Tumor protein 1
- mRNA transcript
- p0–p4: IGF2 promoters 0–4
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Affiliation(s)
- Pierluigi Scalia
- ISOPROG-Somatolink EPFP Research Network, Philadelphia, PA 19102, USA, and 93100 Caltanissetta, Italy
- Sbarro Cancer Institute for Cancer Research and Molecular Medicine, CST, Biology Department, Temple University, Philadelphia, PA 19122, USA
| | - Stephen J Williams
- ISOPROG-Somatolink EPFP Research Network, Philadelphia, PA 19102, USA, and 93100 Caltanissetta, Italy
- Sbarro Cancer Institute for Cancer Research and Molecular Medicine, CST, Biology Department, Temple University, Philadelphia, PA 19122, USA
| | - Yoko Fujita-Yamaguchi
- Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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Liu S, Cao Y, Cui K, Tang Q, Zhao K. Hi-TrAC reveals division of labor of transcription factors in organizing chromatin loops. Nat Commun 2022; 13:6679. [PMID: 36335136 PMCID: PMC9637178 DOI: 10.1038/s41467-022-34276-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/20/2022] [Indexed: 11/08/2022] Open
Abstract
The three-dimensional genomic structure plays a critical role in gene expression, cellular differentiation, and pathological conditions. It is pivotal to elucidate fine-scale chromatin architectures, especially interactions of regulatory elements, to understand the temporospatial regulation of gene expression. In this study, we report Hi-TrAC as a proximity ligation-free, robust, and sensitive technique to profile genome-wide chromatin interactions at high-resolution among regulatory elements. Hi-TrAC detects chromatin looping among accessible regions at single nucleosome resolution. With almost half-million identified loops, we reveal a comprehensive interaction network of regulatory elements across the genome. After integrating chromatin binding profiles of transcription factors, we discover that cohesin complex and CTCF are responsible for organizing long-range chromatin loops, related to domain formation; whereas ZNF143 and HCFC1 are involved in structuring short-range chromatin loops between regulatory elements, which directly regulate gene expression. Thus, we introduce a methodology to identify a delicate and comprehensive network of cis-regulatory elements, revealing the complexity and a division of labor of transcription factors in organizing chromatin loops for genome organization and gene expression.
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Affiliation(s)
- Shuai Liu
- grid.94365.3d0000 0001 2297 5165Laboratory of Epigenome Biology, Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD USA
| | - Yaqiang Cao
- grid.94365.3d0000 0001 2297 5165Laboratory of Epigenome Biology, Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD USA
| | - Kairong Cui
- grid.94365.3d0000 0001 2297 5165Laboratory of Epigenome Biology, Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD USA
| | - Qingsong Tang
- grid.94365.3d0000 0001 2297 5165Laboratory of Epigenome Biology, Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD USA
| | - Keji Zhao
- grid.94365.3d0000 0001 2297 5165Laboratory of Epigenome Biology, Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD USA
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Exploring chromatin structural roles of non-coding RNAs at imprinted domains. Biochem Soc Trans 2021; 49:1867-1879. [PMID: 34338292 PMCID: PMC8421051 DOI: 10.1042/bst20210758] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 12/11/2022]
Abstract
Different classes of non-coding RNA (ncRNA) influence the organization of chromatin. Imprinted gene domains constitute a paradigm for exploring functional long ncRNAs (lncRNAs). Almost all express an lncRNA in a parent-of-origin dependent manner. The mono-allelic expression of these lncRNAs represses close by and distant protein-coding genes, through diverse mechanisms. Some control genes on other chromosomes as well. Interestingly, several imprinted chromosomal domains show a developmentally regulated, chromatin-based mechanism of imprinting with apparent similarities to X-chromosome inactivation. At these domains, the mono-allelic lncRNAs show a relatively stable, focal accumulation in cis. This facilitates the recruitment of Polycomb repressive complexes, lysine methyltranferases and other nuclear proteins — in part through direct RNA–protein interactions. Recent chromosome conformation capture and microscopy studies indicate that the focal aggregation of lncRNA and interacting proteins could play an architectural role as well, and correlates with close positioning of target genes. Higher-order chromatin structure is strongly influenced by CTCF/cohesin complexes, whose allelic association patterns and actions may be influenced by lncRNAs as well. Here, we review the gene-repressive roles of imprinted non-coding RNAs, particularly of lncRNAs, and discuss emerging links with chromatin architecture.
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Patel SK, George B, Rai V. Artificial Intelligence to Decode Cancer Mechanism: Beyond Patient Stratification for Precision Oncology. Front Pharmacol 2020; 11:1177. [PMID: 32903628 PMCID: PMC7438594 DOI: 10.3389/fphar.2020.01177] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/20/2020] [Indexed: 12/13/2022] Open
Abstract
The multitude of multi-omics data generated cost-effectively using advanced high-throughput technologies has imposed challenging domain for research in Artificial Intelligence (AI). Data curation poses a significant challenge as different parameters, instruments, and sample preparations approaches are employed for generating these big data sets. AI could reduce the fuzziness and randomness in data handling and build a platform for the data ecosystem, and thus serve as the primary choice for data mining and big data analysis to make informed decisions. However, AI implication remains intricate for researchers/clinicians lacking specific training in computational tools and informatics. Cancer is a major cause of death worldwide, accounting for an estimated 9.6 million deaths in 2018. Certain cancers, such as pancreatic and gastric cancers, are detected only after they have reached their advanced stages with frequent relapses. Cancer is one of the most complex diseases affecting a range of organs with diverse disease progression mechanisms and the effectors ranging from gene-epigenetics to a wide array of metabolites. Hence a comprehensive study, including genomics, epi-genomics, transcriptomics, proteomics, and metabolomics, along with the medical/mass-spectrometry imaging, patient clinical history, treatments provided, genetics, and disease endemicity, is essential. Cancer Moonshot℠ Research Initiatives by NIH National Cancer Institute aims to collect as much information as possible from different regions of the world and make a cancer data repository. AI could play an immense role in (a) analysis of complex and heterogeneous data sets (multi-omics and/or inter-omics), (b) data integration to provide a holistic disease molecular mechanism, (c) identification of diagnostic and prognostic markers, and (d) monitor patient's response to drugs/treatments and recovery. AI enables precision disease management well beyond the prevalent disease stratification patterns, such as differential expression and supervised classification. This review highlights critical advances and challenges in omics data analysis, dealing with data variability from lab-to-lab, and data integration. We also describe methods used in data mining and AI methods to obtain robust results for precision medicine from "big" data. In the future, AI could be expanded to achieve ground-breaking progress in disease management.
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Affiliation(s)
- Sandip Kumar Patel
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
- Buck Institute for Research on Aging, Novato, CA, United States
| | - Bhawana George
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Vineeta Rai
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, United States
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Noordermeer D, Feil R. Differential 3D chromatin organization and gene activity in genomic imprinting. Curr Opin Genet Dev 2020; 61:17-24. [PMID: 32299027 DOI: 10.1016/j.gde.2020.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 01/08/2023]
Abstract
Genomic imprinting gives rise to parent-of-origin dependent allelic gene expression. Most imprinted genes cluster in domains where differentially methylated regions (DMRs)-carrying CpG methylation on one parental allele-regulate their activity. Several imprinted DMRs bind CTCF on the non-methylated allele. CTCF structures TADs ('Topologically Associating Domains'), which are structural units of transcriptional regulation. Recent investigations show that imprinted domains are embedded within TADs that are similar on both parental chromosomes. Within these TADs, however, allelic subdomains are structured by combinations of mono-allelic and bi-allelic CTCF binding that guide imprinted expression. This emerging view indicates that imprinted chromosomal domains should be considered at the overarching TAD level, and questions how CTCF integrates with other regulatory proteins and lncRNAs to achieve imprinted transcriptional programs.
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Affiliation(s)
- Daan Noordermeer
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
| | - Robert Feil
- Institute of Molecular Genetics of Montpellier (IGMM), University of Montpellier, CNRS, Montpellier, France.
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Llères D, Moindrot B, Pathak R, Piras V, Matelot M, Pignard B, Marchand A, Poncelet M, Perrin A, Tellier V, Feil R, Noordermeer D. CTCF modulates allele-specific sub-TAD organization and imprinted gene activity at the mouse Dlk1-Dio3 and Igf2-H19 domains. Genome Biol 2019; 20:272. [PMID: 31831055 PMCID: PMC6909504 DOI: 10.1186/s13059-019-1896-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 11/22/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Genomic imprinting is essential for mammalian development and provides a unique paradigm to explore intra-cellular differences in chromatin configuration. So far, the detailed allele-specific chromatin organization of imprinted gene domains has mostly been lacking. Here, we explored the chromatin structure of the two conserved imprinted domains controlled by paternal DNA methylation imprints-the Igf2-H19 and Dlk1-Dio3 domains-and assessed the involvement of the insulator protein CTCF in mouse cells. RESULTS Both imprinted domains are located within overarching topologically associating domains (TADs) that are similar on both parental chromosomes. At each domain, a single differentially methylated region is bound by CTCF on the maternal chromosome only, in addition to multiple instances of bi-allelic CTCF binding. Combinations of allelic 4C-seq and DNA-FISH revealed that bi-allelic CTCF binding alone, on the paternal chromosome, correlates with a first level of sub-TAD structure. On the maternal chromosome, additional CTCF binding at the differentially methylated region adds a further layer of sub-TAD organization, which essentially hijacks the existing paternal-specific sub-TAD organization. Perturbation of maternal-specific CTCF binding site at the Dlk1-Dio3 locus, using genome editing, results in perturbed sub-TAD organization and bi-allelic Dlk1 activation during differentiation. CONCLUSIONS Maternal allele-specific CTCF binding at the imprinted Igf2-H19 and the Dlk1-Dio3 domains adds an additional layer of sub-TAD organization, on top of an existing three-dimensional configuration and prior to imprinted activation of protein-coding genes. We speculate that this allele-specific sub-TAD organization provides an instructive or permissive context for imprinted gene activation during development.
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Affiliation(s)
- David Llères
- Institute of Molecular Genetics of Montpellier (IGMM), University of Montpellier, CNRS, Montpellier, France
| | - Benoît Moindrot
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-sud and University Paris-Saclay, Gif-sur-Yvette, France
| | - Rakesh Pathak
- Institute of Molecular Genetics of Montpellier (IGMM), University of Montpellier, CNRS, Montpellier, France
| | - Vincent Piras
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-sud and University Paris-Saclay, Gif-sur-Yvette, France
| | - Mélody Matelot
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-sud and University Paris-Saclay, Gif-sur-Yvette, France
| | - Benoît Pignard
- Institute of Molecular Genetics of Montpellier (IGMM), University of Montpellier, CNRS, Montpellier, France
| | - Alice Marchand
- Institute of Molecular Genetics of Montpellier (IGMM), University of Montpellier, CNRS, Montpellier, France
| | - Mallory Poncelet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-sud and University Paris-Saclay, Gif-sur-Yvette, France
| | - Aurélien Perrin
- Institute of Molecular Genetics of Montpellier (IGMM), University of Montpellier, CNRS, Montpellier, France
| | - Virgile Tellier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-sud and University Paris-Saclay, Gif-sur-Yvette, France
| | - Robert Feil
- Institute of Molecular Genetics of Montpellier (IGMM), University of Montpellier, CNRS, Montpellier, France.
| | - Daan Noordermeer
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-sud and University Paris-Saclay, Gif-sur-Yvette, France.
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Baral K, Rotwein P. The insulin-like growth factor 2 gene in mammals: Organizational complexity within a conserved locus. PLoS One 2019; 14:e0219155. [PMID: 31251794 PMCID: PMC6599137 DOI: 10.1371/journal.pone.0219155] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/17/2019] [Indexed: 01/10/2023] Open
Abstract
The secreted protein, insulin-like growth factor 2 (IGF2), plays a central role in fetal and prenatal growth and development, and is regulated at the genetic level by parental imprinting, being expressed predominantly from the paternally derived chromosome in mice and humans. Here, IGF2/Igf2 and its locus has been examined in 19 mammals from 13 orders spanning ~166 million years of evolutionary development. By using human or mouse DNA segments as queries in genome analyses, and by assessing gene expression using RNA-sequencing libraries, more complexity was identified within IGF2/Igf2 than was annotated previously. Multiple potential 5’ non-coding exons were mapped in most mammals and are presumably linked to distinct IGF2/Igf2 promoters, as shown for several species by interrogating RNA-sequencing libraries. DNA similarity was highest in IGF2/Igf2 coding exons; yet, even though the mature IGF2 protein was conserved, versions of 67 or 70 residues are produced secondary to species-specific maintenance of alternative RNA splicing at a variable intron-exon junction. Adjacent H19 was more divergent than IGF2/Igf2, as expected in a gene for a noncoding RNA, and was identified in only 10/19 species. These results show that common features, including those defining IGF2/Igf2 coding and several non-coding exons, were likely present at the onset of the mammalian radiation, but that others, such as a putative imprinting control region 5’ to H19 and potential enhancer elements 3’ to H19, diversified with speciation. This study also demonstrates that careful analysis of genomic and gene expression repositories can provide new insights into gene structure and regulation.
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Affiliation(s)
- Kabita Baral
- Graduate School, College of Science, University of Texas at El Paso, El Paso, Texas
| | - Peter Rotwein
- Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech Health University Health Sciences Center, El Paso, Texas
- * E-mail:
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Kim JY, Youn HY, Pfeifer K, Eun B. Paternal bias expression of Igf2as is enhancer-dependent on the imprinting cluster of Igf2, H19 and Nctc1 in muscle cells. Anim Cells Syst (Seoul) 2019; 23:288-293. [PMID: 31489250 PMCID: PMC6711144 DOI: 10.1080/19768354.2019.1612780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/08/2019] [Accepted: 04/23/2019] [Indexed: 11/22/2022] Open
Abstract
Igf2, H19, and Nctc1 are linked co-regulated genes on distal mouse chromosome 7. This locus is an important model both for studying mechanisms of monoallelic expression and for elucidating the role of cis-regulatory elements – enhancers and insulators – in organizing chromatin and gene expression across a large domain. In this study we characterize regulated expression of the Igf2 antisense transcript (Igf2as) in primary muscle cells. We demonstrate that Igf2as is imprinted (expressed only from the paternal chromosome). We also show that Igf2as expression during differentiation follows the same patterns as Igf2 and H19. Moreover, this expression is dependent upon the same shared enhancer element. Thus, our work shows that the imprinted cluster includes Igf2as in addition to H19, Igf2, and Nctc1.
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Affiliation(s)
- Jae-Young Kim
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Hwa Young Youn
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Karl Pfeifer
- National Institute of Child Health and Development, National Institutes of Health, Bethesda, USA
| | - Bokkee Eun
- Core-Laboratory for Convergent Translational Research, Korea University College of Medicine, Seoul, South Korea
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Geng T, Liu Y, Xu Y, Jiang Y, Zhang N, Wang Z, Carmichael GG, Taylor HS, Li D, Huang Y. H19 lncRNA Promotes Skeletal Muscle Insulin Sensitivity in Part by Targeting AMPK. Diabetes 2018; 67:2183-2198. [PMID: 30201684 PMCID: PMC6198334 DOI: 10.2337/db18-0370] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 08/24/2018] [Indexed: 12/12/2022]
Abstract
Skeletal muscle plays a pivotal role in regulating systemic glucose homeostasis in part through the conserved cellular energy sensor AMPK. AMPK activation increases glucose uptake, lipid oxidation, and mitochondrial biogenesis, leading to enhanced muscle insulin sensitivity and whole-body energy metabolism. Here we show that the muscle-enriched H19 long noncoding RNA (lncRNA) acts to enhance muscle insulin sensitivity, at least in part, by activating AMPK. We identify the atypical dual-specificity phosphatase DUSP27/DUPD1 as a potentially important downstream effector of H19. We show that DUSP27, which is highly expressed in muscle with previously unknown physiological function, interacts with and activates AMPK in muscle cells. Consistent with decreased H19 expression in the muscle of insulin-resistant human subjects and rodents, mice with genetic H19 ablation exhibit muscle insulin resistance. Furthermore, a high-fat diet downregulates muscle H19 via both posttranscriptional and epigenetic mechanisms. Our results uncover an evolutionarily conserved, highly expressed lncRNA as an important regulator of muscle insulin sensitivity.
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Affiliation(s)
- Tingting Geng
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Endocrinology, First Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, People's Republic of China
| | - Ya Liu
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Veterinary Medicine, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui, People's Republic of China
| | - Yetao Xu
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Obstetrics and Gynecology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Ying Jiang
- Department of Obstetrics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Na Zhang
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT
| | - Zhangsheng Wang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Department of Cardiology, Fifth People's Hospital of Shanghai, Fudan University, Shanghai, People's Republic of China
| | - Gordon G Carmichael
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT
| | - Hugh S Taylor
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
| | - Da Li
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
- Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Yingqun Huang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, CT
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Onco-Multi-OMICS Approach: A New Frontier in Cancer Research. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9836256. [PMID: 30402498 PMCID: PMC6192166 DOI: 10.1155/2018/9836256] [Citation(s) in RCA: 161] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/06/2018] [Indexed: 02/07/2023]
Abstract
The acquisition of cancer hallmarks requires molecular alterations at multiple levels including genome, epigenome, transcriptome, proteome, and metabolome. In the past decade, numerous attempts have been made to untangle the molecular mechanisms of carcinogenesis involving single OMICS approaches such as scanning the genome for cancer-specific mutations and identifying altered epigenetic-landscapes within cancer cells or by exploring the differential expression of mRNA and protein through transcriptomics and proteomics techniques, respectively. While these single-level OMICS approaches have contributed towards the identification of cancer-specific mutations, epigenetic alterations, and molecular subtyping of tumors based on gene/protein-expression, they lack the resolving-power to establish the casual relationship between molecular signatures and the phenotypic manifestation of cancer hallmarks. In contrast, the multi-OMICS approaches involving the interrogation of the cancer cells/tissues in multiple dimensions have the potential to uncover the intricate molecular mechanism underlying different phenotypic manifestations of cancer hallmarks such as metastasis and angiogenesis. Moreover, multi-OMICS approaches can be used to dissect the cellular response to chemo- or immunotherapy as well as discover molecular candidates with diagnostic/prognostic value. In this review, we focused on the applications of different multi-OMICS approaches in the field of cancer research and discussed how these approaches are shaping the field of personalized oncomedicine. We have highlighted pioneering studies from “The Cancer Genome Atlas (TCGA)” consortium encompassing integrated OMICS analysis of over 11,000 tumors from 33 most prevalent forms of cancer. Accumulation of huge cancer-specific multi-OMICS data in repositories like TCGA provides a unique opportunity for the systems biology approach to tackle the complexity of cancer cells through the unification of experimental data and computational/mathematical models. In future, systems biology based approach is likely to predict the phenotypic changes of cancer cells upon chemo-/immunotherapy treatment. This review is sought to encourage investigators to bring these different approaches together for interrogating cancer at molecular, cellular, and systems levels.
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Rotwein P. The complex genetics of human insulin-like growth factor 2 are not reflected in public databases. J Biol Chem 2018; 293:4324-4333. [PMID: 29414792 DOI: 10.1074/jbc.ra117.001573] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/15/2018] [Indexed: 01/02/2023] Open
Abstract
Recent advances in genetics present unique opportunities for enhancing knowledge about human physiology and disease susceptibility. Understanding this information at the individual gene level is challenging and requires extracting, collating, and interpreting data from a variety of public gene repositories. Here, I illustrate this challenge by analyzing the gene for human insulin-like growth factor 2 (IGF2) through the lens of several databases. IGF2, a 67-amino acid secreted peptide, is essential for normal prenatal growth and is involved in other physiological and pathophysiological processes in humans. Surprisingly, none of the genetic databases accurately described or completely delineated human IGF2 gene structure or transcript expression, even though all relevant information could be found in the published literature. Although IGF2 shares multiple features with the mouse Igf2 gene, it has several unique properties, including transcription from five promoters. Both genes undergo parental imprinting, with IGF2/Igf2 being expressed primarily from the paternal chromosome and the adjacent H19 gene from the maternal chromosome. Unlike mouse Igf2, whose expression declines after birth, human IGF2 remains active throughout life. This characteristic has been attributed to a unique human gene promoter that escapes imprinting, but as shown here, it involves several different promoters with distinct tissue-specific expression patterns. Because new testable hypotheses could lead to critical insights into IGF2 actions in human physiology and disease, it is incumbent that our fundamental understanding is accurate. Similar challenges affecting knowledge of other human genes should promote attempts to critically evaluate, interpret, and correct human genetic data in publicly available databases.
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Affiliation(s)
- Peter Rotwein
- From the Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech Health University Health Sciences Center, El Paso, Texas 79905
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12
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Park KS, Mitra A, Rahat B, Kim K, Pfeifer K. Loss of imprinting mutations define both distinct and overlapping roles for misexpression of IGF2 and of H19 lncRNA. Nucleic Acids Res 2018; 45:12766-12779. [PMID: 29244185 PMCID: PMC5727439 DOI: 10.1093/nar/gkx896] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 09/26/2017] [Indexed: 12/26/2022] Open
Abstract
Imprinted genes occur in discrete clusters that are coordinately regulated by shared DNA elements called Imprinting Control Regions. H19 and Igf2 are linked imprinted genes that play critical roles in development. Loss of imprinting (LOI) at the IGF2/H19 locus on the maternal chromosome is associated with the developmental disorder Beckwith Wiedemann Syndrome (BWS) and with several cancers. Here we use comprehensive genetic and genomic analyses to follow muscle development in a mouse model of BWS to dissect the separate and shared roles for misexpression of Igf2 and H19 in the disease phenotype. We show that LOI results in defects in muscle differentiation and hypertrophy and identify primary downstream targets: Igf2 overexpression results in over-activation of MAPK signaling while loss of H19 lncRNA prevents normal down regulation of p53 activity and therefore results in reduced AKT/mTOR signaling. Moreover, we demonstrate instances where H19 and Igf2 misexpression work separately, cooperatively, and antagonistically to establish the developmental phenotype. This study thus identifies new biochemical roles for the H19 lncRNA and underscores that LOI phenotypes are multigenic so that complex interactions will contribute to disease outcomes.
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Affiliation(s)
- Ki-Sun Park
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20814, USA
| | - Apratim Mitra
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20814, USA
| | - Beenish Rahat
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20814, USA
| | - Keekwang Kim
- Department of Biochemistry, Chungnam National University, Daejeon 305-764, Republic of Korea
| | - Karl Pfeifer
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20814, USA
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Long non-coding RNAs (lncRNAs) in skeletal and cardiac muscle: potential therapeutic and diagnostic targets? Clin Sci (Lond) 2016; 130:2245-2256. [DOI: 10.1042/cs20160244] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 09/22/2016] [Indexed: 12/20/2022]
Abstract
The recent discovery that thousands of RNAs are transcribed by the cell but are never translated into protein, highlights a significant void in our current understanding of how transcriptional networks regulate cellular function. This is particularly astounding when we consider that over 75% of the human genome is transcribed into RNA, but only approximately 2% of RNA is translated into known proteins. This raises the question as to what function the other so-called ‘non-coding RNAs’ (ncRNAs) are performing in the cell. Over the last decade, an enormous amount of research has identified several classes of ncRNAs, predominantly short ncRNAs (<200 nt) that have been confirmed to have functional significance. Recent advances in sequencing technology and bioinformatics have also allowed for the identification of a novel class of ncRNAs, termed long ncRNA (lncRNA) (>200 nt). Several studies have recently shown that long non-coding RNAs (lncRNAs) are associated with tissue development and disease, particularly in cell types that undergo differentiation such as stem cells, cancer cells and striated muscle (skeletal/cardiac). Therefore, understanding the function of these lncRNAs and designing strategies to detect and manipulate them, may present novel therapeutic and diagnostic opportunities. This review will explore the current literature on lncRNAs in skeletal and cardiac muscle and discuss their recent implication in development and disease. Lastly, we will also explore the possibility of using lncRNAs as therapeutic and diagnostic tools and discuss the opportunities and potential shortcomings to these applications.
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14
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Gebert C, Rong Q, Jeong S, Iben J, Pfeifer K. H19ICR mediated transcriptional silencing does not require target promoter methylation. Biochem Biophys Res Commun 2016; 476:121-6. [PMID: 27178213 DOI: 10.1016/j.bbrc.2016.05.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 05/03/2016] [Indexed: 10/21/2022]
Abstract
Transcription of the reciprocally imprinted genes Insulin-like growth factor 2 (Igf2) and H19 is orchestrated by the 2.4-kb H19 Imprinting Control Region (H19ICR) located upstream of H19. Three known functions are associated with the H19ICR: (1) it is a germline differentially methylated region, (2) it is a transcriptional insulator, and (3) it is a transcriptional silencer. The molecular mechanisms of the DMR and insulator functions have been well characterized but the basis for the ICR's silencer function is less well understood. In order to study the role the H19ICR intrinsically plays in gene silencing, we transferred the 2.4-kb H19ICR to a heterologous non-imprinted location on chromosome 5, upstream of the alpha fetoprotein (Afp) promoter. Independent of its orientation, the 2.4-kb H19ICR silences transcription from the paternal Afp promoter. Thus silencing is a function intrinsic to this DNA element. Further, ICR mediated silencing is a developmental process that, unexpectedly, does not occur through DNA methylation at the target promoter.
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Affiliation(s)
- Claudia Gebert
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Qi Rong
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sangkyun Jeong
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - James Iben
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Karl Pfeifer
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Zhou J, Yang L, Zhong T, Mueller M, Men Y, Zhang N, Xie J, Giang K, Chung H, Sun X, Lu L, Carmichael GG, Taylor HS, Huang Y. H19 lncRNA alters DNA methylation genome wide by regulating S-adenosylhomocysteine hydrolase. Nat Commun 2015; 6:10221. [PMID: 26687445 PMCID: PMC4703905 DOI: 10.1038/ncomms10221] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 11/16/2015] [Indexed: 02/05/2023] Open
Abstract
DNA methylation is essential for mammalian development and physiology. Here we report that the developmentally regulated H19 lncRNA binds to and inhibits S-adenosylhomocysteine hydrolase (SAHH), the only mammalian enzyme capable of hydrolysing S-adenosylhomocysteine (SAH). SAH is a potent feedback inhibitor of S-adenosylmethionine (SAM)-dependent methyltransferases that methylate diverse cellular components, including DNA, RNA, proteins, lipids and neurotransmitters. We show that H19 knockdown activates SAHH, leading to increased DNMT3B-mediated methylation of an lncRNA-encoding gene Nctc1 within the Igf2-H19-Nctc1 locus. Genome-wide methylation profiling reveals methylation changes at numerous gene loci consistent with SAHH modulation by H19. Our results uncover an unanticipated regulatory circuit involving broad epigenetic alterations by a single abundantly expressed lncRNA that may underlie gene methylation dynamics of development and diseases and suggest that this mode of regulation may extend to other cellular components.
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Affiliation(s)
- Jichun Zhou
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Surgical Oncology, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
| | - Lihua Yang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Obstetrics and Gynecology, Tianjin Renmin Hospital, Tianjin 300000, China
| | - Tianyu Zhong
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi 341000, China
| | - Martin Mueller
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Obstetrics and Gynecology, University Hospital, Bern 3012, Switzerland
| | - Yi Men
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Head and Neck Surgery, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Na Zhang
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Juanke Xie
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Reproductive Medical Center, Henan Provincial People's Hospital, Zhengzhou, Henan 450003, China
| | - Karolyn Giang
- Zymo Research Corporation, Irvine, California 92614, USA
| | - Hunter Chung
- Zymo Research Corporation, Irvine, California 92614, USA
| | - Xueguang Sun
- Zymo Research Corporation, Irvine, California 92614, USA
| | - Lingeng Lu
- Department of Chronic Diseases Epidemiology, Yale School of Public Health, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Gordon G Carmichael
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Hugh S Taylor
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Yingqun Huang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
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Alzhanov D, Rotwein P. Characterizing a distal muscle enhancer in the mouse Igf2 locus. Physiol Genomics 2015; 48:167-72. [PMID: 26645089 DOI: 10.1152/physiolgenomics.00095.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 12/03/2015] [Indexed: 11/22/2022] Open
Abstract
Insulin-like growth factor-2 (IGF2) is highly expressed in skeletal muscle and was identified as a quantitative trait locus for muscle mass. Yet little is known about mechanisms of its regulation in muscle. Recently, a DNA segment found ∼100 kb from the Igf2 gene was identified as a possible muscle transcriptional control element. Here we have developed an in vivo reporter system to assess this putative enhancer by substituting nuclear (n) EGFP for Igf2 coding exons in a bacterial artificial chromosome containing the mouse Igf2 - H19 chromosomal locus. After stable transfection into a mesenchymal stem cell line, individual clones were converted to myoblasts and underwent progressive muscle-specific gene expression and myotube formation in differentiation medium. Transgenic mRNA and nuclear-targeted enhanced green fluorescent protein were produced coincident with endogenous Igf2 mRNA, but only in lines containing an intact distal conserved DNA element. Our results show that a 294 bp DNA fragment containing two E-boxes is a necessary and sufficient long-range enhancer for induction of Igf2 gene transcription during skeletal muscle differentiation and provides a robust experimental platform for its further functional dissection.
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Affiliation(s)
- Damir Alzhanov
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon; and
| | - Peter Rotwein
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon; and Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas
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17
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Bhasin JM, Lee BH, Matkin L, Taylor MG, Hu B, Xu Y, Magi-Galluzzi C, Klein EA, Ting AH. Methylome-wide Sequencing Detects DNA Hypermethylation Distinguishing Indolent from Aggressive Prostate Cancer. Cell Rep 2015; 13:2135-46. [PMID: 26628371 DOI: 10.1016/j.celrep.2015.10.078] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 09/10/2015] [Accepted: 10/28/2015] [Indexed: 01/12/2023] Open
Abstract
A critical need in understanding the biology of prostate cancer is characterizing the molecular differences between indolent and aggressive cases. Because DNA methylation can capture the regulatory state of tumors, we analyzed differential methylation patterns genome-wide among benign prostatic tissue and low-grade and high-grade prostate cancer and found extensive, focal hypermethylation regions unique to high-grade disease. These hypermethylation regions occurred not only in the promoters of genes but also in gene bodies and at intergenic regions that are enriched for DNA-protein binding sites. Integration with existing RNA-sequencing (RNA-seq) and survival data revealed regions where DNA methylation correlates with reduced gene expression associated with poor outcome. Regions specific to aggressive disease are proximal to genes with distinct functions from regions shared by indolent and aggressive disease. Our compendium of methylation changes reveals crucial molecular distinctions between indolent and aggressive prostate cancer.
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Affiliation(s)
- Jeffrey M Bhasin
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA; Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Byron H Lee
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Lars Matkin
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Margaret G Taylor
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Bo Hu
- Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Yaomin Xu
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - Cristina Magi-Galluzzi
- Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Eric A Klein
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Angela H Ting
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA; Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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18
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Sokol M, Jessen KM, Pedersen FS. Human endogenous retroviruses sustain complex and cooperative regulation of gene-containing loci and unannotated megabase-sized regions. Retrovirology 2015; 12:32. [PMID: 25927889 PMCID: PMC4422309 DOI: 10.1186/s12977-015-0161-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/30/2015] [Indexed: 12/19/2022] Open
Abstract
Background Evidence suggests that some human endogenous retroviruses and endogenous retrovirus-like repeats (here collectively ERVs) regulate the expression of neighboring genes in normal and disease states; e.g. the human globin locus is regulated by an ERV9 that coordinates long-range gene switching during hematopoiesis and activates also intergenic transcripts. While complex transcription regulation is associated with integration of certain exogenous retroviruses, comparable regulation sustained by ERVs is less understood. Findings We analyzed ERV transcription using ERV9 consensus sequences and publically available RNA-sequencing, chromatin immunoprecipitation with sequencing (ChIP-seq) and cap analysis gene expression (CAGE) data from ENCODE. We discovered previously undescribed and advanced transcription regulation mechanisms in several human reference cell lines. We show that regulation by ERVs involves long-ranging activations including complex RNA splicing patterns, and transcription of large unannotated regions ranging in size from several hundred kb to around 1 Mb. Moreover, regulation was found to be cooperatively sustained in some loci by multiple ERVs and also non-LTR repeats. Conclusion Our analyses show that endogenous retroviruses sustain advanced transcription regulation in human cell lines, which shows similarities to complex insertional mutagenesis effects exerted by exogenous retroviruses. By exposing previously undescribed regulation effects, this study should prove useful for understanding fundamental transcription mechanisms resulting from evolutionary acquisition of retroviral sequence in the human genome. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0161-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martin Sokol
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, DK-8000, Denmark.
| | - Karen Margrethe Jessen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, DK-8000, Denmark.
| | - Finn Skou Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, DK-8000, Denmark.
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19
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Sokol M, Wabl M, Ruiz IR, Pedersen FS. Novel principles of gamma-retroviral insertional transcription activation in murine leukemia virus-induced end-stage tumors. Retrovirology 2014; 11:36. [PMID: 24886479 PMCID: PMC4098794 DOI: 10.1186/1742-4690-11-36] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 04/28/2014] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Insertional mutagenesis screens of retrovirus-induced mouse tumors have proven valuable in human cancer research and for understanding adverse effects of retroviral-based gene therapies. In previous studies, the assignment of mouse genes to individual retroviral integration sites has been based on close proximity and expression patterns of annotated genes at target positions in the genome. We here employed next-generation RNA sequencing to map retroviral-mouse chimeric junctions genome-wide, and to identify local patterns of transcription activation in T-lymphomas induced by the murine leukemia gamma-retrovirus SL3-3. Moreover, to determine epigenetic integration preferences underlying long-range gene activation by retroviruses, the colocalization propensity with common epigenetic enhancer markers (H3K4Me1 and H3K27Ac) of 6,117 integrations derived from end-stage tumors of more than 2,000 mice was examined. RESULTS We detected several novel mechanisms of retroviral insertional mutagenesis: bidirectional activation of mouse transcripts on opposite sides of a provirus including transcription of unannotated mouse sequence; sense/antisense-type activation of genes located on opposite DNA strands; tandem-type activation of distal genes that are positioned adjacently on the same DNA strand; activation of genes that are not the direct integration targets; combination-type insertional mutagenesis, in which enhancer activation, alternative chimeric splicing and retroviral promoter insertion are induced by a single retrovirus. We also show that irrespective of the distance to transcription start sites, the far majority of retroviruses in end-stage tumors colocalize with H3K4Me1 and H3K27Ac-enriched regions in murine lymphoid tissues. CONCLUSIONS We expose novel retrovirus-induced host transcription activation patterns that reach beyond a single and nearest annotated gene target. Awareness of this previously undescribed layer of complexity may prove important for elucidation of adverse effects in retroviral-based gene therapies. We also show that wild-type gamma-retroviruses are frequently positioned at enhancers, suggesting that integration into regulatory regions is specific and also subject to positive selection for sustaining long-range gene activation in end-stage tumors. Altogether, this study should prove useful for extrapolating adverse outcomes of retroviral vector therapies, and for understanding fundamental cellular regulatory principles and retroviral biology.
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Affiliation(s)
- Martin Sokol
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Matthias Wabl
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143, USA
| | - Irene Rius Ruiz
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Finn Skou Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
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20
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Neguembor MV, Jothi M, Gabellini D. Long noncoding RNAs, emerging players in muscle differentiation and disease. Skelet Muscle 2014; 4:8. [PMID: 24685002 PMCID: PMC3973619 DOI: 10.1186/2044-5040-4-8] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 03/11/2014] [Indexed: 12/18/2022] Open
Abstract
The vast majority of the mammalian genome is transcribed giving rise to many different types of noncoding RNAs. Among them, long noncoding RNAs are the most numerous and functionally versatile class. Indeed, the lncRNA repertoire might be as rich as the proteome. LncRNAs have emerged as key regulators of gene expression at multiple levels. They play important roles in the regulation of development, differentiation and maintenance of cell identity and they also contribute to disease. In this review, we present recent advances in the biology of lncRNAs in muscle development and differentiation. We will also discuss the contribution of lncRNAs to muscle disease with a particular focus on Duchenne and facioscapulohumeral muscular dystrophies.
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Affiliation(s)
| | | | - Davide Gabellini
- Dulbecco Telethon Institute at San Raffaele Scientific Institute, Division of Regenerative Medicine, Stem cells, and Gene therapy, DIBIT2, 5A3, Via Olgettina 58, 20132 Milano, Italy.
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21
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Dey BK, Pfeifer K, Dutta A. The H19 long noncoding RNA gives rise to microRNAs miR-675-3p and miR-675-5p to promote skeletal muscle differentiation and regeneration. Genes Dev 2014; 28:491-501. [PMID: 24532688 PMCID: PMC3950346 DOI: 10.1101/gad.234419.113] [Citation(s) in RCA: 379] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The H19 long noncoding RNA is repressed after birth, except in skeletal muscle. Dey et al. discover that H19 exon1 encodes miR-675-3p and miR-675-5p. The inhibition of myogenesis by H19 depletion is rescued by expression of miR-675-3p and miR-675-5p. The abnormal skeletal muscle regeneration in H19-deficient mice is rectified by reintroducing miR-675-3p and miR-675-5p. These miRs target the anti-differentiation Smad transcription factors and the DNA replication initiation factor Cdc6. In summary, H19 gives rise to microRNAs to promote skeletal muscle differentiation and regeneration. Regulated expression of the H19 long noncoding RNA gene has been well characterized as a paradigm for genomic imprinting, but the H19 RNA's biological function remains largely unclear. H19 is abundantly expressed maternally in embryonic tissues but is strongly repressed after birth, and significant transcription persists only in skeletal muscle. Thus, we examined the role of the H19 RNA in skeletal muscle differentiation and regeneration. Knockdown of H19 RNA in myoblast cells and H19 knockout mouse satellite cells decreases differentiation. H19 exon1 encodes two conserved microRNAs, miR-675-3p and miR-675-5p, both of which are induced during skeletal muscle differentiation. The inhibition of myogenesis by H19 depletion during myoblast differentiation is rescued by exogenous expression of miR-675-3p and miR-675-5p. H19-deficient mice display abnormal skeletal muscle regeneration after injury, which is rectified by reintroduction of miR-675-3p and miR-675-5p. miR-675-3p and miR-675-5p function by directly targeting and down-regulating the anti-differentiation Smad transcription factors critical for the bone morphogenetic protein (BMP) pathway and the DNA replication initiation factor Cdc6. Therefore, the H19 long noncoding RNA has a critical trans-regulatory function in skeletal muscle differentiation and regeneration that is mediated by the microRNAs encoded within H19.
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Affiliation(s)
- Bijan K Dey
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
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22
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Eun B, Sampley ML, Van Winkle MT, Good AL, Kachman MM, Pfeifer K. The Igf2/H19 muscle enhancer is an active transcriptional complex. Nucleic Acids Res 2013; 41:8126-34. [PMID: 23842673 PMCID: PMC3783178 DOI: 10.1093/nar/gkt597] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 06/13/2013] [Accepted: 06/15/2013] [Indexed: 02/06/2023] Open
Abstract
In eukaryotic cells, gene expression is mediated by enhancer activation of RNA polymerase at distant promoters. Recently, distinctions between enhancers and promoters have been blurred by the discovery that enhancers are associated with RNA polymerase and are sites of RNA synthesis. Here, we present an analysis of the insulin-like growth factor 2/H19 muscle enhancer. This enhancer includes a short conserved core element that is organized into chromatin typical of mammalian enhancers, binds tissue-specific transcription factors and functions on its own in vitro to activate promoter transcription. However, in a chromosomal context, this element is not sufficient to activate distant promoters. Instead, enhancer function also requires transcription in cis of a long non-coding RNA, Nctc1. Thus, the insulin-like growth factor 2/H19 enhancer is an active transcriptional complex whose own transcription is essential to its function.
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Affiliation(s)
- Bokkee Eun
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA and Core-Laboratory, College of Medicine, Korea University, Seoul 136-701, Republic of Korea
| | - Megan L. Sampley
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA and Core-Laboratory, College of Medicine, Korea University, Seoul 136-701, Republic of Korea
| | - Matthew T. Van Winkle
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA and Core-Laboratory, College of Medicine, Korea University, Seoul 136-701, Republic of Korea
| | - Austin L. Good
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA and Core-Laboratory, College of Medicine, Korea University, Seoul 136-701, Republic of Korea
| | - Marika M. Kachman
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA and Core-Laboratory, College of Medicine, Korea University, Seoul 136-701, Republic of Korea
| | - Karl Pfeifer
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA and Core-Laboratory, College of Medicine, Korea University, Seoul 136-701, Republic of Korea
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