51
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Paraskevopoulos M, McGuigan AP. Application of CRISPR screens to investigate mammalian cell competition. Brief Funct Genomics 2021; 20:135-147. [PMID: 33782689 DOI: 10.1093/bfgp/elab020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 02/26/2021] [Accepted: 03/08/2021] [Indexed: 11/14/2022] Open
Abstract
Cell competition is defined as the context-dependent elimination of cells that is mediated by intercellular communication, such as paracrine or contact-dependent cell signaling, and/or mechanical stresses. It is considered to be a quality control mechanism that facilitates the removal of suboptimal cells from both adult and embryonic tissues. Cell competition, however, can also be hijacked by transformed cells to acquire a 'super-competitor' status and outcompete the normal epithelium to establish a precancerous field. To date, many genetic drivers of cell competition have been identified predominately through studies in Drosophila. Especially during the last couple of years, ethylmethanesulfonate-based genetic screens have been instrumental to our understanding of the molecular regulators behind some of the most common competition mechanisms in Drosophila, namely competition due to impaired ribosomal function (or anabolism) and mechanical sensitivity. Despite recent findings in Drosophila and in mammalian models of cell competition, the drivers of mammalian cell competition remain largely elusive. Since the discovery of CRISPR/Cas9, its use in functional genomics has been indispensable to uncover novel cancer vulnerabilities. We envision that CRISPR/Cas9 screens will enable systematic, genome-scale probing of mammalian cell competition to discover novel mutations that not only trigger cell competition but also identify novel molecular components that are essential for the recognition and elimination of less fit cells. In this review, we summarize recent contributions that further our understanding of the molecular mechanisms of cell competition by genetic screening in Drosophila, and provide our perspective on how similar and novel screening strategies made possible by whole-genome CRISPR/Cas9 screening can advance our understanding of mammalian cell competition in the future.
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52
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Chin MY, Espinosa JA, Pohan G, Markossian S, Arkin MR. Reimagining dots and dashes: Visualizing structure and function of organelles for high-content imaging analysis. Cell Chem Biol 2021; 28:320-337. [PMID: 33600764 PMCID: PMC7995685 DOI: 10.1016/j.chembiol.2021.01.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/18/2020] [Accepted: 01/20/2021] [Indexed: 12/16/2022]
Abstract
Organelles are responsible for biochemical and cellular processes that sustain life and their dysfunction causes diseases from cancer to neurodegeneration. While researchers are continuing to appreciate new roles of organelles in disease, the rapid development of specifically targeted fluorescent probes that report on the structure and function of organelles will be critical to accelerate drug discovery. Here, we highlight four organelles that collectively exemplify the progression of phenotypic discovery, starting with mitochondria, where many functional probes have been described, then continuing with lysosomes and Golgi and concluding with nascently described membraneless organelles. We introduce emerging probe designs to explore organelle-specific morphology and dynamics and highlight recent case studies using high-content analysis to stimulate further development of probes and approaches for organellar high-throughput screening.
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Affiliation(s)
- Marcus Y Chin
- Small Molecule Discovery Center and Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Jether Amos Espinosa
- Small Molecule Discovery Center and Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Grace Pohan
- Small Molecule Discovery Center and Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Sarine Markossian
- Small Molecule Discovery Center and Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Michelle R Arkin
- Small Molecule Discovery Center and Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA.
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53
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Vierbuchen T, Fitzgerald KA. Long non-coding RNAs in antiviral immunity. Semin Cell Dev Biol 2021; 111:126-134. [DOI: 10.1016/j.semcdb.2020.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/07/2020] [Accepted: 06/12/2020] [Indexed: 12/15/2022]
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54
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Kanfer G, Sarraf SA, Maman Y, Baldwin H, Dominguez-Martin E, Johnson KR, Ward ME, Kampmann M, Lippincott-Schwartz J, Youle RJ. Image-based pooled whole-genome CRISPRi screening for subcellular phenotypes. J Cell Biol 2021; 220:e202006180. [PMID: 33464298 PMCID: PMC7816647 DOI: 10.1083/jcb.202006180] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 10/17/2020] [Accepted: 12/02/2020] [Indexed: 12/13/2022] Open
Abstract
Genome-wide CRISPR screens have transformed our ability to systematically interrogate human gene function, but are currently limited to a subset of cellular phenotypes. We report a novel pooled screening approach for a wider range of cellular and subtle subcellular phenotypes. Machine learning and convolutional neural network models are trained on the subcellular phenotype to be queried. Genome-wide screening then utilizes cells stably expressing dCas9-KRAB (CRISPRi), photoactivatable fluorescent protein (PA-mCherry), and a lentiviral guide RNA (gRNA) pool. Cells are screened by using microscopy and classified by artificial intelligence (AI) algorithms, which precisely identify the genetically altered phenotype. Cells with the phenotype of interest are photoactivated and isolated via flow cytometry, and the gRNAs are identified by sequencing. A proof-of-concept screen accurately identified PINK1 as essential for Parkin recruitment to mitochondria. A genome-wide screen identified factors mediating TFEB relocation from the nucleus to the cytosol upon prolonged starvation. Twenty-one of the 64 hits called by the neural network model were independently validated, revealing new effectors of TFEB subcellular localization. This approach, AI-photoswitchable screening (AI-PS), offers a novel screening platform capable of classifying a broad range of mammalian subcellular morphologies, an approach largely unattainable with current methodologies at genome-wide scale.
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Affiliation(s)
- Gil Kanfer
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - Shireen A. Sarraf
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Yaakov Maman
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Heather Baldwin
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Eunice Dominguez-Martin
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Kory R. Johnson
- Bioinformatics Section, Information Technology Program, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Michael E. Ward
- Inherited Neurodegenerative Diseases Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Martin Kampmann
- Institute for Neurodegenerative Diseases, Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA
| | | | - Richard J. Youle
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
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55
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Yan X, Stuurman N, Ribeiro SA, Tanenbaum ME, Horlbeck MA, Liem CR, Jost M, Weissman JS, Vale RD. High-content imaging-based pooled CRISPR screens in mammalian cells. J Cell Biol 2021; 220:211696. [PMID: 33465779 PMCID: PMC7821101 DOI: 10.1083/jcb.202008158] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 11/17/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
CRISPR (clustered regularly interspaced short palindromic repeats)-based gene inactivation provides a powerful means for linking genes to particular cellular phenotypes. CRISPR-based screening typically uses large genomic pools of single guide RNAs (sgRNAs). However, this approach is limited to phenotypes that can be enriched by chemical selection or FACS sorting. Here, we developed a microscopy-based approach, which we name optical enrichment, to select cells displaying a particular CRISPR-induced phenotype by automated imaging-based computation, mark them by photoactivation of an expressed photoactivatable fluorescent protein, and then isolate the fluorescent cells using fluorescence-activated cell sorting (FACS). A plugin was developed for the open source software μManager to automate the phenotypic identification and photoactivation of cells, allowing ∼1.5 million individual cells to be screened in 8 h. We used this approach to screen 6,092 sgRNAs targeting 544 genes for their effects on nuclear size regulation and identified 14 bona fide hits. These results present a scalable approach to facilitate imaging-based pooled CRISPR screens.
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Affiliation(s)
- Xiaowei Yan
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA
| | - Nico Stuurman
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA
| | - Susana A. Ribeiro
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Cairn Biosciences, Inc., San Francisco, CA
| | - Marvin E. Tanenbaum
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Oncode Institute, Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, Netherlands
| | - Max A. Horlbeck
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Boston Children's Hospital, Boston, MA
| | - Christina R. Liem
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,University of California, San Diego, San Diego, CA
| | - Marco Jost
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA
| | - Jonathan S. Weissman
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Whitehead Institute and Department of Biology, MIT, Cambridge, MA
| | - Ronald D. Vale
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA,Correspondence to Ronald D. Vale:
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56
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Goyal B, Yadav SRM, Awasthee N, Gupta S, Kunnumakkara AB, Gupta SC. Diagnostic, prognostic, and therapeutic significance of long non-coding RNA MALAT1 in cancer. Biochim Biophys Acta Rev Cancer 2021; 1875:188502. [PMID: 33428963 DOI: 10.1016/j.bbcan.2021.188502] [Citation(s) in RCA: 165] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/30/2020] [Accepted: 01/02/2021] [Indexed: 12/20/2022]
Abstract
Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is a widely studied lncRNA in cancer. Although dispensable for normal physiology, MALAT1 is important for cancer-related pathways regulation. It is localized in the nuclear speckles periphery along with centrally located pre-RNA splicing factors. MALAT1 associated cancer signaling pathways include MAPK/ERK, PI3K/AKT, β-catenin/Wnt, Hippo, VEGF, YAP, etc. Molecular tools such as immunoprecipitation, RNA pull-down, reporter assay, Northern blotting, microarray, and q-RT-PCR has been used to elucidate MALAT1's function in cancer pathogenesis. MALAT1 can regulate multiple steps in the development of tumours. The diagnostic and prognostic significance of MALAT1 has been demonstrated in cancers of the breast, cervix, colorectum, gallbladder, lung, ovary, pancreas, prostate, glioma, hepatocellular carcinoma, and multiple myeloma. MALAT1 has also emerged as a novel therapeutic target for solid as well as hematological malignancies. In experimental models, siRNA and antisense oligonucleotide (ASO) based strategy has been used for targeting MALAT1. The lncRNA has also been targeted for the chemosensitization and radiosensitization of cancer cells. However, most studies have been performed in preclinical models. How the cross-talk of MALAT1 with other signaling pathways affect cancer pathogenesis is the focus of this article. The diagnostic, prognostic, and therapeutic significance of MALAT1 in multiple cancer types are discussed.
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Affiliation(s)
- Bela Goyal
- Department of Biochemistry, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
| | - Shashi Ranjan Mani Yadav
- Department of Biochemistry, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
| | - Nikee Awasthee
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Sweety Gupta
- Department of Radiation Oncology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
| | - Ajaikumar B Kunnumakkara
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, 781039, India
| | - Subash Chandra Gupta
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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57
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Fell CW, Nagy V. Cellular Models and High-Throughput Screening for Genetic Causality of Intellectual Disability. Trends Mol Med 2021; 27:220-230. [PMID: 33397633 DOI: 10.1016/j.molmed.2020.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/17/2022]
Abstract
Intellectual disabilities (ID) are a type of neurodevelopmental disorder (NDD). They can have a genetic cause, including an emerging class of ID centring around Rho GTPases, such as Ras-related C3 botulinum toxin substrate 1 (RAC1). Guidelines for establishing genetic causality include the use of cellular models, which often have morphological aberrations, a long-standing hallmark of ID. Disease cellular models can facilitate high-throughput screening (HTS) of chemical or genetic perturbations, which can provide translatable biological insight. Here, we discuss a class of IDs centring around RAC1. We review novel and established cellular models of ID, including mouse and human primary cells and reprogrammed or induced neurons. Finally, we review progress and remaining challenges in the adoption of HTS methodologies by the community studying neurological disorders.
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Affiliation(s)
- Christopher W Fell
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD), 1090 Vienna, Austria; Research Centre for Molecular Medicine (CeMM) of the Austrian Academy of Sciences, 1090 Vienna, Austria; Department of Neurology, Medical University of Vienna (MUW), 1090 Vienna, Austria
| | - Vanja Nagy
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD), 1090 Vienna, Austria; Research Centre for Molecular Medicine (CeMM) of the Austrian Academy of Sciences, 1090 Vienna, Austria; Department of Neurology, Medical University of Vienna (MUW), 1090 Vienna, Austria.
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58
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Abstract
The recent advent of genome-scale imaging has enabled single-cell omics analysis in a spatially resolved manner in intact cells and tissues. These advances allow gene expression profiling of individual cells, and hence in situ identification and spatial mapping of cell types, in complex tissues. The high spatial resolution of these approaches further allows determination of the spatial organizations of the genome and transcriptome inside cells, both of which are key regulatory mechanisms for gene expression.
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Affiliation(s)
- Xiaowei Zhuang
- Howard Hughes Medical Institute, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Department of Physics, Harvard University, Cambridge, MA, USA.
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59
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Mechanisms of Long Noncoding RNA Nuclear Retention. Trends Biochem Sci 2020; 45:947-960. [DOI: 10.1016/j.tibs.2020.07.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/27/2020] [Accepted: 07/15/2020] [Indexed: 12/11/2022]
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60
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Krey K, Babnis AW, Pichlmair A. System-Based Approaches to Delineate the Antiviral Innate Immune Landscape. Viruses 2020; 12:E1196. [PMID: 33096788 PMCID: PMC7589202 DOI: 10.3390/v12101196] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/19/2020] [Accepted: 10/19/2020] [Indexed: 12/12/2022] Open
Abstract
Viruses pose substantial challenges for society, economy, healthcare systems, and research. Their distinctive pathologies are based on specific interactions with cellular factors. In order to develop new antiviral treatments, it is of central importance to understand how viruses interact with their host and how infected cells react to the virus on a molecular level. Invading viruses are commonly sensed by components of the innate immune system, which is composed of a highly effective yet complex network of proteins that, in most cases, mediate efficient virus inhibition. Central to this process is the activity of interferons and other cytokines that coordinate the antiviral response. So far, numerous methods have been used to identify how viruses interact with cellular processes and revealed that the innate immune response is highly complex and involves interferon-stimulated genes and their binding partners as functional factors. Novel approaches and careful experimental design, combined with large-scale, high-throughput methods and cutting-edge analysis pipelines, have to be utilized to delineate the antiviral innate immune landscape at a global level. In this review, we describe different currently used screening approaches, how they contributed to our knowledge on virus-host interactions, and essential considerations that have to be taken into account when planning such experiments.
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Affiliation(s)
- Karsten Krey
- School of Medicine, Institute of Virology, Technical University of Munich, 81675 Munich, Germany; (K.K.); (A.W.B.)
| | - Aleksandra W. Babnis
- School of Medicine, Institute of Virology, Technical University of Munich, 81675 Munich, Germany; (K.K.); (A.W.B.)
| | - Andreas Pichlmair
- School of Medicine, Institute of Virology, Technical University of Munich, 81675 Munich, Germany; (K.K.); (A.W.B.)
- German Center for Infection Research (DZIF), Munich Partner Site, 80538 Munich, Germany
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61
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Matos MR, Ho SM, Schrode N, Brennand KJ. Integration of CRISPR-engineering and hiPSC-based models of psychiatric genomics. Mol Cell Neurosci 2020; 107:103532. [PMID: 32712198 PMCID: PMC7484226 DOI: 10.1016/j.mcn.2020.103532] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/14/2020] [Accepted: 07/17/2020] [Indexed: 02/06/2023] Open
Abstract
Neuropsychiatric disorders are highly heritable polygenic disorders arising from the complex interplay of highly penetrant rare variants and common variants of small effect. There is a large index of comorbidity and shared genetic risk between disorders, reflecting the pleiotropy of individual variants as well as predicted downstream pathway-level convergence. Importantly, the mechanism(s) through which psychiatric disease-associated variants interact to contribute to disease risk remains unknown. Human induced pluripotent stem cell (hiPSC)-based models are increasingly useful for the systematic study of the complex genetics associated with brain diseases, particularly when combined with CRISPR-mediated genomic engineering, which together facilitate isogenic comparisons of defined neuronal cell types. In this review, we discuss the latest CRISPR technologies and consider how they can be successfully applied to the functional characterization of the growing list genetic variants linked to psychiatric disease.
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Affiliation(s)
- Marliette R Matos
- Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America
| | - Seok-Man Ho
- Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Department of Stem Cell and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America
| | - Nadine Schrode
- Department of Genetics and Genomics, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America.
| | - Kristen J Brennand
- Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Department of Stem Cell and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Department of Genetics and Genomics, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States of America.
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62
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Joseph SA, Taglialatela A, Leuzzi G, Huang JW, Cuella-Martin R, Ciccia A. Time for remodeling: SNF2-family DNA translocases in replication fork metabolism and human disease. DNA Repair (Amst) 2020; 95:102943. [PMID: 32971328 DOI: 10.1016/j.dnarep.2020.102943] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/24/2020] [Accepted: 07/26/2020] [Indexed: 02/07/2023]
Abstract
Over the course of DNA replication, DNA lesions, transcriptional intermediates and protein-DNA complexes can impair the progression of replication forks, thus resulting in replication stress. Failure to maintain replication fork integrity in response to replication stress leads to genomic instability and predisposes to the development of cancer and other genetic disorders. Multiple DNA damage and repair pathways have evolved to allow completion of DNA replication following replication stress, thus preserving genomic integrity. One of the processes commonly induced in response to replication stress is fork reversal, which consists in the remodeling of stalled replication forks into four-way DNA junctions. In normal conditions, fork reversal slows down replication fork progression to ensure accurate repair of DNA lesions and facilitates replication fork restart once the DNA lesions have been removed. However, in certain pathological situations, such as the deficiency of DNA repair factors that protect regressed forks from nuclease-mediated degradation, fork reversal can cause genomic instability. In this review, we describe the complex molecular mechanisms regulating fork reversal, with a focus on the role of the SNF2-family fork remodelers SMARCAL1, ZRANB3 and HLTF, and highlight the implications of fork reversal for tumorigenesis and cancer therapy.
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Affiliation(s)
- Sarah A Joseph
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Angelo Taglialatela
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Giuseppe Leuzzi
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Jen-Wei Huang
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Raquel Cuella-Martin
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA.
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63
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Abstract
Neurodegenerative, neurodevelopmental and neuropsychiatric disorders are among the greatest public health challenges, as many lack disease-modifying treatments. A major reason for the absence of effective therapies is our limited understanding of the causative molecular and cellular mechanisms. Genome-wide association studies are providing a growing catalogue of disease-associated genetic variants, and the next challenge is to elucidate how these variants cause disease and to translate this understanding into therapies. This Review describes how new CRISPR-based functional genomics approaches can uncover disease mechanisms and therapeutic targets in neurological diseases. The bacterial CRISPR system can be used in experimental disease models to edit genomes and to control gene expression levels through CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa). These genetic perturbations can be implemented in massively parallel genetic screens to evaluate the functional consequences for human cells. CRISPR screens are particularly powerful in combination with induced pluripotent stem cell technology, which enables the derivation of differentiated cell types, such as neurons and glia, and brain organoids from cells obtained from patients. Modelling of disease-associated changes in gene expression via CRISPRi and CRISPRa can pinpoint causal changes. In addition, genetic modifier screens can be used to elucidate disease mechanisms and causal determinants of cell type-selective vulnerability and to identify therapeutic targets.
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64
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Arun G, Aggarwal D, Spector DL. MALAT1 Long Non-Coding RNA: Functional Implications. Noncoding RNA 2020; 6:E22. [PMID: 32503170 PMCID: PMC7344863 DOI: 10.3390/ncrna6020022] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 12/13/2022] Open
Abstract
The mammalian genome is pervasively transcribed and the functional significance of many long non-coding RNA (lncRNA) transcripts are gradually being elucidated. Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is one of the most well-studied lncRNAs. MALAT1 is a highly conserved nuclear retained lncRNA that is abundantly expressed in cells and tissues and has been shown to play a role in regulating genes at both the transcriptional and post-transcriptional levels in a context-dependent manner. However, Malat1 has been shown to be dispensable for normal development and viability in mice. Interestingly, accumulating evidence suggests that MALAT1 plays an important role in numerous diseases including cancer. Here, we discuss the current state-of-knowledge in regard to MALAT1 with respect to its function, role in diseases, and the potential therapeutic opportunities for targeting MALAT1 using antisense oligonucleotides and small molecules.
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Affiliation(s)
- Gayatri Arun
- Envisagenics, 101 Avenue of the Americas, New York, NY 10013, USA;
| | - Disha Aggarwal
- Graduate Program in Genetics, Stony Brook University, Stony Brook, New York, NY 11794, USA;
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA
| | - David L. Spector
- Graduate Program in Genetics, Stony Brook University, Stony Brook, New York, NY 11794, USA;
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY 11724, USA
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65
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Hasle N, Cooke A, Srivatsan S, Huang H, Stephany JJ, Krieger Z, Jackson D, Tang W, Pendyala S, Monnat RJ, Trapnell C, Hatch EM, Fowler DM. High-throughput, microscope-based sorting to dissect cellular heterogeneity. Mol Syst Biol 2020; 16:e9442. [PMID: 32500953 PMCID: PMC7273721 DOI: 10.15252/msb.20209442] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 04/23/2020] [Accepted: 04/29/2020] [Indexed: 12/24/2022] Open
Abstract
Microscopy is a powerful tool for characterizing complex cellular phenotypes, but linking these phenotypes to genotype or RNA expression at scale remains challenging. Here, we present Visual Cell Sorting, a method that physically separates hundreds of thousands of live cells based on their visual phenotype. Automated imaging and phenotypic analysis directs selective illumination of Dendra2, a photoconvertible fluorescent protein expressed in live cells; these photoactivated cells are then isolated using fluorescence-activated cell sorting. First, we use Visual Cell Sorting to assess hundreds of nuclear localization sequence variants in a pooled format, identifying variants that improve nuclear localization and enabling annotation of nuclear localization sequences in thousands of human proteins. Second, we recover cells that retain normal nuclear morphologies after paclitaxel treatment, and then derive their single-cell transcriptomes to identify pathways associated with paclitaxel resistance in cancers. Unlike alternative methods, Visual Cell Sorting depends on inexpensive reagents and commercially available hardware. As such, it can be readily deployed to uncover the relationships between visual cellular phenotypes and internal states, including genotypes and gene expression programs.
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Affiliation(s)
- Nicholas Hasle
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | | | - Sanjay Srivatsan
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | - Heather Huang
- Divisions of Basic Sciences and Human BiologyFred Hutchinson Cancer Research CenterSeattleWAUSA
| | - Jason J Stephany
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | - Zachary Krieger
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | - Dana Jackson
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | - Weiliang Tang
- Department of PathologyUniversity of WashingtonSeattleWAUSA
| | - Sriram Pendyala
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | - Raymond J Monnat
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
- Department of PathologyUniversity of WashingtonSeattleWAUSA
| | - Cole Trapnell
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | - Emily M Hatch
- Divisions of Basic Sciences and Human BiologyFred Hutchinson Cancer Research CenterSeattleWAUSA
| | - Douglas M Fowler
- Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
- Department of BioengineeringUniversity of WashingtonSeattleWAUSA
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66
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Fazal FM, Chang HY. Subcellular Spatial Transcriptomes: Emerging Frontier for Understanding Gene Regulation. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2020; 84:31-45. [PMID: 32482897 PMCID: PMC7426137 DOI: 10.1101/sqb.2019.84.040352] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
RNAs are trafficked and localized with exquisite precision inside the cell. Studies of candidate messenger RNAs have shown the vital importance of RNA subcellular location in development and cellular function. New sequencing- and imaging-based methods are providing complementary insights into subcellular localization of RNAs transcriptome-wide. APEX-seq and ribosome profiling as well as proximity-labeling approaches have revealed thousands of transcript isoforms are localized to distinct cytotopic locations, including locations that defy biochemical fractionation and hence were missed by prior studies. Sequences in the 3' and 5' untranslated regions (UTRs) serve as "zip codes" to direct transcripts to particular locales, and it is clear that intronic and retrotransposable sequences within transcripts have been co-opted by cells to control localization. Molecular motors, nuclear-to-cytosol RNA export, liquid-liquid phase separation, RNA modifications, and RNA structure dynamically shape the subcellular transcriptome. Location-based RNA regulation continues to pose new mysteries for the field, yet promises to reveal insights into fundamental cell biology and disease mechanisms.
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Affiliation(s)
- Furqan M Fazal
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, California 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, California 94305, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA
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67
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Ivanova E, Khmelinskii A. (Photo)convert to pooled visual screening. Mol Syst Biol 2020; 16:e9640. [PMID: 32543109 PMCID: PMC7296822 DOI: 10.15252/msb.20209640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Pooled genetic screening is a powerful method to systematically link genotype to phenotype and gain insights into biological processes, but applying it to visual phenotypes such as cell morphology or protein localization has remained a challenge. In their recent work, Fowler and colleagues (Hasle et al, 2020) describe an elegant approach for high-throughput cell sorting according to visual phenotypes based on selective photoconversion. This allows combining the advantages of high-content phenotyping by fluorescence microscopy with the efficiency of pooled screening to dissect complex phenotypes.
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68
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Wheeler EC, Vu AQ, Einstein JM, DiSalvo M, Ahmed N, Van Nostrand EL, Shishkin AA, Jin W, Allbritton NL, Yeo GW. Pooled CRISPR screens with imaging on microraft arrays reveals stress granule-regulatory factors. Nat Methods 2020; 17:636-642. [PMID: 32393832 PMCID: PMC7357298 DOI: 10.1038/s41592-020-0826-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 04/06/2020] [Indexed: 12/12/2022]
Abstract
Genetic screens using pooled CRISPR-based approaches are scalable and inexpensive, but restricted to standard readouts, including survival, proliferation and sortable markers. However, many biologically relevant cell states involve cellular and subcellular changes that are only accessible by microscopic visualization, and are currently impossible to screen with pooled methods. Here we combine pooled CRISPR-Cas9 screening with microraft array technology and high-content imaging to screen image-based phenotypes (CRaft-ID; CRISPR-based microRaft followed by guide RNA identification). By isolating microrafts that contain genetic clones harboring individual guide RNAs (gRNA), we identify RNA-binding proteins (RBPs) that influence the formation of stress granules, the punctate protein-RNA assemblies that form during stress. To automate hit identification, we developed a machine-learning model trained on nuclear morphology to remove unhealthy cells or imaging artifacts. In doing so, we identified and validated previously uncharacterized RBPs that modulate stress granule abundance, highlighting the applicability of our approach to facilitate image-based pooled CRISPR screens.
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Affiliation(s)
- Emily C Wheeler
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA
| | - Anthony Q Vu
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA
| | - Jaclyn M Einstein
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA
| | - Matthew DiSalvo
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill and Raleigh, NC, USA
| | - Noorsher Ahmed
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA
| | - Eric L Van Nostrand
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA
| | - Alexander A Shishkin
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA
- Eclipse BioInnovations, San Diego, CA, USA
| | - Wenhao Jin
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA
| | - Nancy L Allbritton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill and Raleigh, NC, USA
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA.
- Institute for Genomic Medicine and UCSD Stem Cell Program, University of California San Diego, La Jolla, CA, USA.
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69
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Awwad DA. Beyond classic editing: innovative CRISPR approaches for functional studies of long non-coding RNA. Biol Methods Protoc 2019; 4:bpz017. [PMID: 32161809 PMCID: PMC6994087 DOI: 10.1093/biomethods/bpz017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 09/06/2019] [Accepted: 11/19/2019] [Indexed: 12/26/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) makeup a considerable part of the non-coding human genome and had been well-established as crucial players in an array of biological processes. In spite of their abundance and versatile roles, their functional characteristics remain largely undiscovered mainly due to the lack of suitable genetic manipulation tools. The emerging CRISPR/Cas9 technology has been widely adapted in several studies that aim to screen and identify novel lncRNAs as well as interrogate the functional properties of specific lncRNAs. However, the complexity of lncRNAs genes and the regulatory mechanisms that govern their transcription, as well as their unique functionality pose several limitations the utilization of classic CRISPR methods in lncRNAs functional studies. Here, we overview the unique characteristics of lncRNAs transcription and function and the suitability of the CRISPR toolbox for applications in functional characterization of lncRNAs. We discuss some of the novel variations to the classic CRISPR/Cas9 system that have been tailored and applied previously to study several aspects of lncRNAs functionality. Finally, we share perspectives on the potential applications of various CRISPR systems, including RNA-targeting, in the direct editing and manipulation of lncRNAs.
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Affiliation(s)
- Dahlia A Awwad
- Center of X-Ray Determination of Structure of Matter (CXDS), Helmi Institute of Biomedical Research, Zewail City of Science and Technology, Giza, Cairo, Egypt
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70
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Wang M, Chen K, Wu Q, Peng R, Zhang R, Li J. RCasFISH: CRISPR/dCas9-Mediated in Situ Imaging of mRNA Transcripts in Fixed Cells and Tissues. Anal Chem 2019; 92:2468-2475. [PMID: 31782306 DOI: 10.1021/acs.analchem.9b03797] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Meng Wang
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
- Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, P. R. China
- Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing 100730, P. R. China
| | - Kun Chen
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
- Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, P. R. China
- Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing 100730, P. R. China
| | - Qisheng Wu
- Division of Pathology & Laboratory Medicine, Hebei Yanda Lu Daopei Hospital, Langfang 065201, P. R. China
| | - Rongxue Peng
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
- Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing 100730, P. R. China
| | - Rui Zhang
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
- Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, P. R. China
- Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing 100730, P. R. China
| | - Jinming Li
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
- Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, P. R. China
- Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing 100730, P. R. China
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71
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Feldman D, Singh A, Schmid-Burgk JL, Carlson RJ, Mezger A, Garrity AJ, Zhang F, Blainey PC. Optical Pooled Screens in Human Cells. Cell 2019; 179:787-799.e17. [PMID: 31626775 PMCID: PMC6886477 DOI: 10.1016/j.cell.2019.09.016] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 07/08/2019] [Accepted: 09/13/2019] [Indexed: 01/06/2023]
Abstract
Genetic screens are critical for the systematic identification of genes underlying cellular phenotypes. Pooling gene perturbations greatly improves scalability but is not compatible with imaging of complex and dynamic cellular phenotypes. Here, we introduce a pooled approach for optical genetic screens in mammalian cells. We use targeted in situ sequencing to demultiplex a library of genetic perturbations following image-based phenotyping. We screened a set of 952 genes across millions of cells for involvement in nuclear factor κB (NF-κB) signaling by imaging the translocation of RelA (p65) to the nucleus. Screening at a single time point across 3 cell lines recovered 15 known pathway components, while repeating the screen with live-cell imaging revealed a role for Mediator complex subunits in regulating the duration of p65 nuclear retention. These results establish a highly multiplexed approach to image-based screens of spatially and temporally defined phenotypes with pooled libraries.
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Affiliation(s)
- David Feldman
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Physics, MIT, Cambridge, MA 02142, USA
| | - Avtar Singh
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Rebecca J Carlson
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Health Sciences and Technology, MIT, Cambridge, MA 02142, USA
| | - Anja Mezger
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | | | - Feng Zhang
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Biological Engineering, MIT, Cambridge, MA 02142, USA; McGovern Institute for Brain Research at MIT, Cambridge, MA 02142, USA; Department of Brain and Cognitive Science, MIT, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, MIT, Cambridge, MA 02142, USA
| | - Paul C Blainey
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Biological Engineering, MIT, Cambridge, MA 02142, USA; Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA 02142, USA.
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