1
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Binet R, Lambert JP, Tomkova M, Tischfield S, Baggiolini A, Picaud S, Sarkar S, Louphrasitthiphol P, Dias D, Carreira S, Humphrey TC, Fillipakopoulos P, White R, Goding CR. DNA damage remodels the MITF interactome to increase melanoma genomic instability. Genes Dev 2024; 38:70-94. [PMID: 38316520 PMCID: PMC10903946 DOI: 10.1101/gad.350740.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024]
Abstract
Since genome instability can drive cancer initiation and progression, cells have evolved highly effective and ubiquitous DNA damage response (DDR) programs. However, some cells (for example, in skin) are normally exposed to high levels of DNA-damaging agents. Whether such high-risk cells possess lineage-specific mechanisms that tailor DNA repair to the tissue remains largely unknown. Using melanoma as a model, we show here that the microphthalmia-associated transcription factor MITF, a lineage addition oncogene that coordinates many aspects of melanocyte and melanoma biology, plays a nontranscriptional role in shaping the DDR. On exposure to DNA-damaging agents, MITF is phosphorylated at S325, and its interactome is dramatically remodeled; most transcription cofactors dissociate, and instead MITF interacts with the MRE11-RAD50-NBS1 (MRN) complex. Consequently, cells with high MITF levels accumulate stalled replication forks and display defects in homologous recombination-mediated repair associated with impaired MRN recruitment to DNA damage. In agreement with this, high MITF levels are associated with increased single-nucleotide and copy number variant burdens in melanoma. Significantly, the SUMOylation-defective MITF-E318K melanoma predisposition mutation recapitulates the effects of DNA-PKcs-phosphorylated MITF. Our data suggest that a nontranscriptional function of a lineage-restricted transcription factor contributes to a tissue-specialized modulation of the DDR that can impact cancer initiation.
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Affiliation(s)
- Romuald Binet
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
| | - Jean-Philippe Lambert
- Department of Molecular Medicine, Cancer Research Center, Université Laval, Québec City, Québec G1V 4G2, Canada
- Endocrinology-Nephrology Axis, CHU de Québec-Université Laval Research Center, Québec City, Québec G1V 4G2, Canada
| | - Marketa Tomkova
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
- Department of Biochemistry and Molecular Medicine, University of California, Davis, Davis, California 95616, USA
| | - Samuel Tischfield
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
- Marie-Josée and Henry R. Kravis Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Arianna Baggiolini
- Center for Stem Cell Biology and Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Sarah Picaud
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Sovan Sarkar
- Cancer Research UK, Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Pakavarin Louphrasitthiphol
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
| | - Diogo Dias
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
| | - Suzanne Carreira
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
| | - Timothy C Humphrey
- Cancer Research UK, Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Panagis Fillipakopoulos
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Richard White
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Colin R Goding
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom;
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2
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Ovadia S, Cui G, Elkon R, Cohen-Gulkar M, Zuk-Bar N, Tuoc T, Jing N, Ashery-Padan R. SWI/SNF complexes are required for retinal pigmented epithelium differentiation and for the inhibition of cell proliferation and neural differentiation programs. Development 2023; 150:dev201488. [PMID: 37522516 PMCID: PMC10482007 DOI: 10.1242/dev.201488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 07/14/2023] [Indexed: 08/01/2023]
Abstract
During embryonic development, tissue-specific transcription factors and chromatin remodelers function together to ensure gradual, coordinated differentiation of multiple lineages. Here, we define this regulatory interplay in the developing retinal pigmented epithelium (RPE), a neuroectodermal lineage essential for the development, function and maintenance of the adjacent retina. We present a high-resolution spatial transcriptomic atlas of the developing mouse RPE and the adjacent ocular mesenchyme obtained by geographical position sequencing (Geo-seq) of a single developmental stage of the eye that encompasses young and more mature ocular progenitors. These transcriptomic data, available online, reveal the key transcription factors and their gene regulatory networks during RPE and ocular mesenchyme differentiation. Moreover, conditional inactivation followed by Geo-seq revealed that this differentiation program is dependent on the activity of SWI/SNF complexes, shown here to control the expression and activity of RPE transcription factors and, at the same time, inhibit neural progenitor and cell proliferation genes. The findings reveal the roles of the SWI/SNF complexes in controlling the intersection between RPE and neural cell fates and the coupling of cell-cycle exit and differentiation.
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Affiliation(s)
- Shai Ovadia
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Guizhong Cui
- Guangzhou National Laboratory, Department of Basic Research, Guangzhou 510005, China
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Mazal Cohen-Gulkar
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nitay Zuk-Bar
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tran Tuoc
- Department of Human Genetics, Ruhr University of Bochum, 44791 Bochum, Germany
| | - Naihe Jing
- Guangzhou National Laboratory, Department of Basic Research, Guangzhou 510005, China
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
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3
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Binet R, Lambert JP, Tomkova M, Tischfield S, Baggiolini A, Picaud S, Sarkar S, Louphrasitthiphol P, Dias D, Carreira S, Humphrey T, Fillipakopoulos P, White R, Goding CR. DNA damage-induced interaction between a lineage addiction oncogenic transcription factor and the MRN complex shapes a tissue-specific DNA Damage Response and cancer predisposition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.21.537819. [PMID: 37131595 PMCID: PMC10153263 DOI: 10.1101/2023.04.21.537819] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Since genome instability can drive cancer initiation and progression, cells have evolved highly effective and ubiquitous DNA Damage Response (DDR) programs. However, some cells, in skin for example, are normally exposed to high levels of DNA damaging agents. Whether such high-risk cells possess lineage-specific mechanisms that tailor DNA repair to the tissue remains largely unknown. Here we show, using melanoma as a model, that the microphthalmia-associated transcription factor MITF, a lineage addition oncogene that coordinates many aspects of melanocyte and melanoma biology, plays a non-transcriptional role in shaping the DDR. On exposure to DNA damaging agents, MITF is phosphorylated by ATM/DNA-PKcs, and unexpectedly its interactome is dramatically remodelled; most transcription (co)factors dissociate, and instead MITF interacts with the MRE11-RAD50-NBS1 (MRN) complex. Consequently, cells with high MITF levels accumulate stalled replication forks, and display defects in homologous recombination-mediated repair associated with impaired MRN recruitment to DNA damage. In agreement, high MITF levels are associated with increased SNV burden in melanoma. Significantly, the SUMOylation-defective MITF-E318K melanoma predisposition mutation recapitulates the effects of ATM/DNA-PKcs-phosphorylated MITF. Our data suggest that a non-transcriptional function of a lineage-restricted transcription factor contributes to a tissue-specialised modulation of the DDR that can impact cancer initiation.
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Affiliation(s)
- Romuald Binet
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
| | - Jean-Philippe Lambert
- Department of Molecular Medicine, Cancer Research Center and Big Data Research Center, Université Laval, Quebec, Canada; Endocrinology – Nephrology Axis, CHU de Québec – Université Laval Research Center, Quebec City, QC, Canada, G1V 4G2
| | - Marketa Tomkova
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
- Department of Biochemistry and Molecular Medicine, University of California, Davis, USA
| | - Samuel Tischfield
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Marie-Josée and Henry R. Kravis Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Arianna Baggiolini
- Center for Stem Cell Biology and Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Sarah Picaud
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Sovan Sarkar
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Pakavarin Louphrasitthiphol
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
| | - Diogo Dias
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
| | - Suzanne Carreira
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
| | - Timothy Humphrey
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Panagis Fillipakopoulos
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Richard White
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Colin R Goding
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, OX3 7DQ, UK
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4
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Basuroy T, Dreier M, Baum C, Blomquist T, Trumbly R, Filipp FV, de la Serna IL. Epigenetic and pharmacological control of pigmentation via Bromodomain Protein 9 (BRD9). Pigment Cell Melanoma Res 2023; 36:19-32. [PMID: 36112085 PMCID: PMC10091956 DOI: 10.1111/pcmr.13068] [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: 05/25/2022] [Revised: 08/01/2022] [Accepted: 09/14/2022] [Indexed: 12/31/2022]
Abstract
Lineage-specific differentiation programs are activated by epigenetic changes in chromatin structure. Melanin-producing melanocytes maintain a gene expression program ensuring appropriate enzymatic conversion of metabolites into the pigment, melanin, and transfer to surrounding cells. During neuroectodermal development, SMARCA4 (BRG1), the catalytic subunit of SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complexes, is essential for lineage specification. SMARCA4 is also required for development of multipotent neural crest precursors into melanoblasts, which differentiate into pigment-producing melanocytes. In addition to the catalytic domain, SMARCA4 and several SWI/SNF subunits contain bromodomains which are amenable to pharmacological inhibition. We investigated the effects of pharmacological inhibitors of SWI/SNF bromodomains on melanocyte differentiation. Strikingly, treatment of murine melanoblasts and human neonatal epidermal melanocytes with selected bromodomain inhibitors abrogated melanin synthesis and visible pigmentation. Using functional genomics, iBRD9, a small molecule selective for the bromodomain of BRD9 was found to repress pigmentation-specific gene expression. Depletion of BRD9 confirmed a requirement for expression of pigmentation genes in the differentiation program from melanoblasts into pigmented melanocytes and in melanoma cells. Chromatin immunoprecipitation assays showed that iBRD9 disrupts the occupancy of BRD9 and the catalytic subunit SMARCA4 at melanocyte-specific loci. These data indicate that BRD9 promotes melanocyte pigmentation whereas pharmacological inhibition of BRD9 is repressive.
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Affiliation(s)
- Tupa Basuroy
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Megan Dreier
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Caitlin Baum
- Department of Pathology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Thomas Blomquist
- Department of Pathology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Robert Trumbly
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA.,Department of Medical Education, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Fabian V Filipp
- Metaflux, Broadway, San Diego, California, USA.,Cancer Systems Biology, Institute for Diabetes and Cancer, Helmholtz Zentrum München, Munich, Germany.,School of Life Sciences Weihenstephan, Technical University München, Freising, Germany
| | - Ivana L de la Serna
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
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5
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Rubanov A, Berico P, Hernando E. Epigenetic Mechanisms Underlying Melanoma Resistance to Immune and Targeted Therapies. Cancers (Basel) 2022; 14:cancers14235858. [PMID: 36497341 PMCID: PMC9738385 DOI: 10.3390/cancers14235858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/22/2022] [Indexed: 11/30/2022] Open
Abstract
Melanoma is an aggressive skin cancer reliant on early detection for high likelihood of successful treatment. Solar UV exposure transforms melanocytes into highly mutated tumor cells that metastasize to the liver, lungs, and brain. Even upon resection of the primary tumor, almost thirty percent of patients succumb to melanoma within twenty years. Identification of key melanoma genetic drivers led to the development of pharmacological BRAFV600E and MEK inhibitors, significantly improving metastatic patient outcomes over traditional cytotoxic chemotherapy or pioneering IFN-α and IL-2 immune therapies. Checkpoint blockade inhibitors releasing the immunosuppressive effects of CTLA-4 or PD-1 proved to be even more effective and are the standard first-line treatment. Despite these major improvements, durable responses to immunotherapy and targeted therapy have been hindered by intrinsic or acquired resistance. In addition to gained or selected genetic alterations, cellular plasticity conferred by epigenetic reprogramming is emerging as a driver of therapy resistance. Epigenetic regulation of chromatin accessibility drives gene expression and establishes distinct transcriptional cell states. Here we review how aberrant chromatin, transcriptional, and epigenetic regulation contribute to therapy resistance and discuss how targeting these programs sensitizes melanoma cells to immune and targeted therapies.
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Affiliation(s)
- Andrey Rubanov
- Department of Pathology, NYU Grossman School of Medicine, New York, NY 10016, USA
- Interdisciplinary Melanoma Cooperative Group, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA
| | - Pietro Berico
- Department of Pathology, NYU Grossman School of Medicine, New York, NY 10016, USA
- Interdisciplinary Melanoma Cooperative Group, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA
| | - Eva Hernando
- Department of Pathology, NYU Grossman School of Medicine, New York, NY 10016, USA
- Interdisciplinary Melanoma Cooperative Group, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA
- Correspondence:
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6
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Gelmi MC, Houtzagers LE, Strub T, Krossa I, Jager MJ. MITF in Normal Melanocytes, Cutaneous and Uveal Melanoma: A Delicate Balance. Int J Mol Sci 2022; 23:6001. [PMID: 35682684 PMCID: PMC9181002 DOI: 10.3390/ijms23116001] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
Microphthalmia-associated transcription factor (MITF) is an important regulator of melanogenesis and melanocyte development. Although it has been studied extensively in cutaneous melanoma, the role of MITF in uveal melanoma (UM) has not been explored in much detail. We review the literature about the role of MITF in normal melanocytes, in cutaneous melanoma, and in UM. In normal melanocytes, MITF regulates melanocyte development, melanin synthesis, and melanocyte survival. The expression profile and the behaviour of MITF-expressing cells suggest that MITF promotes local proliferation and inhibits invasion, inflammation, and epithelial-to-mesenchymal (EMT) transition. Loss of MITF expression leads to increased invasion and inflammation and is more prevalent in malignant cells. Cutaneous melanoma cells switch between MITF-high and MITF-low states in different phases of tumour development. In UM, MITF loss is associated with loss of BAP1 protein expression, which is a marker of poor prognosis. These data indicate a dual role for MITF in benign and malignant melanocytic cells.
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Affiliation(s)
- Maria Chiara Gelmi
- Department of Ophthalmology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands; (M.C.G.); (L.E.H.)
| | - Laurien E. Houtzagers
- Department of Ophthalmology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands; (M.C.G.); (L.E.H.)
| | - Thomas Strub
- Université Côte d’Azur, 06103 Nice, France; (T.S.); (I.K.)
- Inserm, Biology and Pathologies of Melanocytes, Team1, Equipe Labellisée Ligue 2020, Centre Méditerranéen de Médecine Moléculaire, 06204 Nice, France
| | - Imène Krossa
- Université Côte d’Azur, 06103 Nice, France; (T.S.); (I.K.)
- Inserm, Biology and Pathologies of Melanocytes, Team1, Equipe Labellisée Ligue 2020, Centre Méditerranéen de Médecine Moléculaire, 06204 Nice, France
| | - Martine J. Jager
- Department of Ophthalmology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands; (M.C.G.); (L.E.H.)
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7
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Kenny C, Dilshat R, Seberg HE, Van Otterloo E, Bonde G, Helverson A, Franke CM, Steingrímsson E, Cornell RA. TFAP2 paralogs facilitate chromatin access for MITF at pigmentation and cell proliferation genes. PLoS Genet 2022; 18:e1010207. [PMID: 35580127 PMCID: PMC9159589 DOI: 10.1371/journal.pgen.1010207] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 06/01/2022] [Accepted: 04/19/2022] [Indexed: 12/13/2022] Open
Abstract
In developing melanocytes and in melanoma cells, multiple paralogs of the Activating-enhancer-binding Protein 2 family of transcription factors (TFAP2) contribute to expression of genes encoding pigmentation regulators, but their interaction with Microphthalmia transcription factor (MITF), a master regulator of these cells, is unclear. Supporting the model that TFAP2 facilitates MITF's ability to activate expression of pigmentation genes, single-cell seq analysis of zebrafish embryos revealed that pigmentation genes are only expressed in the subset of mitfa-expressing cells that also express tfap2 paralogs. To test this model in SK-MEL-28 melanoma cells we deleted the two TFAP2 paralogs with highest expression, TFAP2A and TFAP2C, creating TFAP2 knockout (TFAP2-KO) cells. We then assessed gene expression, chromatin accessibility, binding of TFAP2A and of MITF, and the chromatin marks H3K27Ac and H3K27Me3 which are characteristic of active enhancers and silenced chromatin, respectively. Integrated analyses of these datasets indicate TFAP2 paralogs directly activate enhancers near genes enriched for roles in pigmentation and proliferation, and directly repress enhancers near genes enriched for roles in cell adhesion. Consistently, compared to WT cells, TFAP2-KO cells proliferate less and adhere to one another more. TFAP2 paralogs and MITF co-operatively activate a subset of enhancers, with the former necessary for MITF binding and chromatin accessibility. By contrast, TFAP2 paralogs and MITF do not appear to co-operatively inhibit enhancers. These studies reveal a mechanism by which TFAP2 profoundly influences the set of genes activated by MITF, and thereby the phenotype of pigment cells and melanoma cells.
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Affiliation(s)
- Colin Kenny
- Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Ramile Dilshat
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Hannah E. Seberg
- Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Eric Van Otterloo
- Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Gregory Bonde
- Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Annika Helverson
- Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Christopher M. Franke
- Department of Surgery, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Eiríkur Steingrímsson
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Robert A. Cornell
- Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
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8
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Dreier MR, de la Serna IL. SWI/SNF Chromatin Remodeling Enzymes in Melanoma. EPIGENOMES 2022; 6:epigenomes6010010. [PMID: 35323214 PMCID: PMC8947417 DOI: 10.3390/epigenomes6010010] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/07/2022] [Accepted: 03/14/2022] [Indexed: 11/16/2022] Open
Abstract
Melanoma is an aggressive malignancy that arises from the transformation of melanocytes on the skin, mucosal membranes, and uvea of the eye. SWI/SNF chromatin remodeling enzymes are multi-subunit complexes that play important roles in the development of the melanocyte lineage and in the response to ultraviolet radiation, a key environmental risk factor for developing cutaneous melanoma. Exome sequencing has revealed frequent loss of function mutations in genes encoding SWI/SNF subunits in melanoma. However, some SWI/SNF subunits have also been demonstrated to have pro-tumorigenic roles in melanoma and to affect sensitivity to therapeutics. This review summarizes studies that have implicated SWI/SNF components in melanomagenesis and have evaluated how SWI/SNF subunits modulate the response to current therapeutics.
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Enhancing Therapeutic Approaches for Melanoma Patients Targeting Epigenetic Modifiers. Cancers (Basel) 2021; 13:cancers13246180. [PMID: 34944799 PMCID: PMC8699560 DOI: 10.3390/cancers13246180] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/30/2021] [Accepted: 12/03/2021] [Indexed: 12/25/2022] Open
Abstract
Melanoma is the least common but deadliest type of skin cancer. Melanomagenesis is driven by a series of mutations and epigenetic alterations in oncogenes and tumor suppressor genes that allow melanomas to grow, evolve, and metastasize. Epigenetic alterations can also lead to immune evasion and development of resistance to therapies. Although the standard of care for melanoma patients includes surgery, targeted therapies, and immune checkpoint blockade, other therapeutic approaches like radiation therapy, chemotherapy, and immune cell-based therapies are used for patients with advanced disease or unresponsive to the conventional first-line therapies. Targeted therapies such as the use of BRAF and MEK inhibitors and immune checkpoint inhibitors such as anti-PD-1 and anti-CTLA4 only improve the survival of a small subset of patients. Thus, there is an urgent need to identify alternative standalone or combinatorial therapies. Epigenetic modifiers have gained attention as therapeutic targets as they modulate multiple cellular and immune-related processes. Due to melanoma's susceptibility to extrinsic factors and reversible nature, epigenetic drugs are investigated as a therapeutic avenue and as adjuvants for targeted therapies and immune checkpoint inhibitors, as they can sensitize and/or reverse resistance to these therapies, thus enhancing their therapeutic efficacy. This review gives an overview of the role of epigenetic changes in melanoma progression and resistance. In addition, we evaluate the latest advances in preclinical and clinical research studying combinatorial therapies and discuss the use of epigenetic drugs such as HDAC and DNMT inhibitors as potential adjuvants for melanoma patients.
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10
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Zhou S, Zeng H, Huang J, Lei L, Tong X, Li S, Zhou Y, Guo H, Khan M, Luo L, Xiao R, Chen J, Zeng Q. Epigenetic regulation of melanogenesis. Ageing Res Rev 2021; 69:101349. [PMID: 33984527 DOI: 10.1016/j.arr.2021.101349] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 02/07/2023]
Abstract
Melanogenesis is a complex process in which melanin is synthesized in melanocytes and transported to keratinocytes, which involves multiple genes and signaling pathways. Epigenetics refers to the potential genetic changes that affect gene expression without involving changes in the original sequence of DNA nucleotides. DNA methylation regulates the expression of key genes such as tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), dopachrome tautomerase (DCT) and microphthalmia-associated transcription factor (MITF), as well as paracrine factors such as stem cell factor (SCF) and endothelin-1 (ET-1) in melanogenesis. Potential DNA methylation sites are present in the genes of melanogenesis-related signaling pathways such as "Wnt", "PI3K/Akt/CREB" and "MAPK". H3K27 acetylation is abundant in melanogenesis-related genes. Both the upstream activation and downstream regulation of MITF depend on histone acetyltransferase CBP/p300, and pH-induced H3K27 acetylation may be the amplifying mechanism of MITF's effect. HDAC1 and HDAC10 catalyze histone deacetylation of melanogenesis-related gene promoters. Chromatin remodelers SWI/SNF complex and ISWI complex use the energy of ATP hydrolysis to rearrange nucleosomes, while their active subunits BRG1, BRM and BPTF, act as activators and cofactors of MITF. MicroRNAs (miRNAs) can directly target a large number of melanogenesis-related genes, while long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) regulate melanogenesis in a variety of ways. Interactions exist among the epigenetic mechanisms of melanogenesis. For example, the methyl CpG binding domain protein 2 (MeCP2) links DNA methylation, histone deacetylation, and histone methylation. Epigenetic-based therapy provides novel opportunities for treating dermatoses that are caused by pigmentation disturbances. This review summarizes the epigenetic regulation mechanisms of melanogenesis, and examines the pathogenesis and treatment of epigenetics in pigmentation disorders.
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11
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Dilshat R, Vu HN, Steingrímsson E. Epigenetic regulation during melanocyte development and homeostasis. Exp Dermatol 2021; 30:1033-1050. [PMID: 34003523 DOI: 10.1111/exd.14391] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/09/2021] [Accepted: 05/09/2021] [Indexed: 12/26/2022]
Abstract
Melanocytes originate in the neural crest as precursor cells which then migrate and proliferate to reach their destination where they differentiate into pigment-producing cells. Melanocytes not only determine the colour of hair, skin and eyes but also protect against the harmful effects of UV irradiation. The establishment of the melanocyte lineage is regulated by a defined set of transcription factors and signalling pathways that direct the specific gene expression programmes underpinning melanoblast specification, survival, migration, proliferation and differentiation. In addition, epigenetic modifiers and replacement histones play key roles in regulating gene expression and its timing during the different steps of this process. Here, we discuss the evidence for the role of epigenetic regulators in melanocyte development and function and how they interact with transcription factors and signalling pathways to establish and maintain this important cell lineage.
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Affiliation(s)
- Ramile Dilshat
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Hong Nhung Vu
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Eiríkur Steingrímsson
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, BioMedical Center, University of Iceland, Reykjavik, Iceland
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12
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Rago F, Elliott G, Li A, Sprouffske K, Kerr G, Desplat A, Abramowski D, Chen JT, Farsidjani A, Xiang KX, Bushold G, Feng Y, Shirley MD, Bric A, Vattay A, Möbitz H, Nakajima K, Adair CD, Mathieu S, Ntaganda R, Smith T, Papillon JPN, Kauffmann A, Ruddy DA, Bhang HEC, Castelletti D, Jagani Z. The Discovery of SWI/SNF Chromatin Remodeling Activity as a Novel and Targetable Dependency in Uveal Melanoma. Mol Cancer Ther 2020; 19:2186-2195. [PMID: 32747420 DOI: 10.1158/1535-7163.mct-19-1013] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/15/2019] [Accepted: 07/21/2020] [Indexed: 11/16/2022]
Abstract
Uveal melanoma is a rare and aggressive cancer that originates in the eye. Currently, there are no approved targeted therapies and very few effective treatments for this cancer. Although activating mutations in the G protein alpha subunits, GNAQ and GNA11, are key genetic drivers of the disease, few additional drug targets have been identified. Recently, studies have identified context-specific roles for the mammalian SWI/SNF chromatin remodeling complexes (also known as BAF/PBAF) in various cancer lineages. Here, we find evidence that the SWI/SNF complex is essential through analysis of functional genomics screens and further validation in a panel of uveal melanoma cell lines using both genetic tools and small-molecule inhibitors of SWI/SNF. In addition, we describe a functional relationship between the SWI/SNF complex and the melanocyte lineage-specific transcription factor Microphthalmia-associated Transcription Factor, suggesting that these two factors cooperate to drive a transcriptional program essential for uveal melanoma cell survival. These studies highlight a critical role for SWI/SNF in uveal melanoma, and demonstrate a novel path toward the treatment of this cancer.
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Affiliation(s)
- Florencia Rago
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - GiNell Elliott
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Ailing Li
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | | | - Grainne Kerr
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Aurore Desplat
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Julie T Chen
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Ali Farsidjani
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Kay X Xiang
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Geoffrey Bushold
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Yun Feng
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Matthew D Shirley
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Anka Bric
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Anthony Vattay
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Henrik Möbitz
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | | | - Simon Mathieu
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Rukundo Ntaganda
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Troy Smith
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | | | | | - David A Ruddy
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | - Hyo-Eun C Bhang
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts
| | | | - Zainab Jagani
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts.
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13
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Raja DA, Gotherwal V, Burse SA, Subramaniam YJ, Sultan F, Vats A, Gautam H, Sharma B, Sharma S, Singh A, Sivasubbu S, Gokhale RS, Natarajan VT. pH-controlled histone acetylation amplifies melanocyte differentiation downstream of MITF. EMBO Rep 2020; 21:e48333. [PMID: 31709752 PMCID: PMC6945066 DOI: 10.15252/embr.201948333] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 10/04/2019] [Accepted: 10/15/2019] [Indexed: 12/20/2022] Open
Abstract
Tanning response and melanocyte differentiation are mediated by the central transcription factor MITF. This involves the rapid and selective induction of melanocyte maturation genes, while concomitantly the expression of other effector genes is maintained. In this study, using cell-based and zebrafish model systems, we report on a pH-mediated feed-forward mechanism of epigenetic regulation that enables selective amplification of the melanocyte maturation program. We demonstrate that MITF activation directly elevates the expression of the enzyme carbonic anhydrase 14 (CA14). Nuclear localization of CA14 leads to an increase of the intracellular pH, resulting in the activation of the histone acetyl transferase p300/CBP. In turn, enhanced H3K27 histone acetylation at selected differentiation genes facilitates their amplified expression via MITF. CRISPR-mediated targeted missense mutation of CA14 in zebrafish results in the formation of immature acidic melanocytes with decreased pigmentation, establishing a central role for this mechanism during melanocyte differentiation in vivo. Thus, we describe an epigenetic control system via pH modulation that reinforces cell fate determination by altering chromatin dynamics.
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Affiliation(s)
- Desingu Ayyappa Raja
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Vishvabandhu Gotherwal
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Shaunak A Burse
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Yogaspoorthi J Subramaniam
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Farina Sultan
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Archana Vats
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
| | - Hemlata Gautam
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
| | - Babita Sharma
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Sachin Sharma
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
- Present address:
National Institute of ImmunologyNew DelhiIndia
| | - Archana Singh
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | | | - Rajesh S Gokhale
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Present address:
National Institute of ImmunologyNew DelhiIndia
| | - Vivek T Natarajan
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
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14
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Abstract
An incomplete view of the mechanisms that drive metastasis, the primary cause of cancer-related death, has been a major barrier to development of effective therapeutics and prognostic diagnostics. Increasing evidence indicates that the interplay between microenvironment, genetic lesions, and cellular plasticity drives the metastatic cascade and resistance to therapies. Here, using melanoma as a model, we outline the diversity and trajectories of cell states during metastatic dissemination and therapy exposure, and highlight how understanding the magnitude and dynamics of nongenetic reprogramming in space and time at single-cell resolution can be exploited to develop therapeutic strategies that capitalize on nongenetic tumor evolution.
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Affiliation(s)
- Florian Rambow
- Laboratory for Molecular Cancer Biology, Center for Cancer Biology, Vlaams Instituut voor Biotechnologie (VIB), Herestraat 49, 3000 Leuven, Belgium
- Laboratory for Molecular Cancer Biology, Department of Oncology, KULeuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Jean-Christophe Marine
- Laboratory for Molecular Cancer Biology, Center for Cancer Biology, Vlaams Instituut voor Biotechnologie (VIB), Herestraat 49, 3000 Leuven, Belgium
- Laboratory for Molecular Cancer Biology, Department of Oncology, KULeuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Colin R Goding
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
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15
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Abstract
In this review, Goding and Arnheiter present the current understanding of MITF's role and regulation in development and disease and highlight key areas where our knowledge of MITF regulation and function is limited. All transcription factors are equal, but some are more equal than others. In the 25 yr since the gene encoding the microphthalmia-associated transcription factor (MITF) was first isolated, MITF has emerged as a key coordinator of many aspects of melanocyte and melanoma biology. Like all transcription factors, MITF binds to specific DNA sequences and up-regulates or down-regulates its target genes. What marks MITF as being remarkable among its peers is the sheer range of biological processes that it appears to coordinate. These include cell survival, differentiation, proliferation, invasion, senescence, metabolism, and DNA damage repair. In this article we present our current understanding of MITF's role and regulation in development and disease, as well as those of the MITF-related factors TFEB and TFE3, and highlight key areas where our knowledge of MITF regulation and function is limited.
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Affiliation(s)
- Colin R Goding
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford OX3 7DQ, United Kingdom
| | - Heinz Arnheiter
- National Institute of Neurological Disorders and Stroke, National Institutes of Heath, Bethesda, Maryland 20824, USA
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16
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Laurette P, Coassolo S, Davidson G, Michel I, Gambi G, Yao W, Sohier P, Li M, Mengus G, Larue L, Davidson I. Chromatin remodellers Brg1 and Bptf are required for normal gene expression and progression of oncogenic Braf-driven mouse melanoma. Cell Death Differ 2019; 27:29-43. [PMID: 31065107 DOI: 10.1038/s41418-019-0333-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 03/04/2019] [Accepted: 03/28/2019] [Indexed: 11/09/2022] Open
Abstract
Somatic oncogenic mutation of BRAF coupled with inactivation of PTEN constitute a frequent combination of genomic alterations driving the development of human melanoma. Mice genetically engineered to conditionally express oncogenic BrafV600E and inactivate Pten in melanocytes following tamoxifen treatment rapidly develop melanoma. While early-stage melanomas comprised melanin-pigmented Mitf and Dct-expressing cells, expression of these and other melanocyte identity genes was lost in later stage tumours that showed histological and molecular characteristics of de-differentiated neural crest type cells. Melanocyte identity genes displayed loss of active chromatin marks and RNA polymerase II and gain of heterochromatin marks, indicating epigenetic reprogramming during tumour progression. Nevertheless, late-stage tumour cells grown in culture re-expressed Mitf, and melanocyte markers and Mitf together with Sox10 coregulated a large number of genes essential for their growth. In this melanoma model, somatic inactivation that the catalytic Brg1 (Smarca4) subunit of the SWI/SNF complex and the scaffolding Bptf subunit of the NuRF complex delayed tumour formation and deregulated large and overlapping gene expression programs essential for normal tumour cell growth. Moreover, we show that Brg1 and Bptf coregulated many genes together with Mitf and Sox10. Together these transcription factors and chromatin remodelling complexes orchestrate essential gene expression programs in mouse melanoma cells.
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Affiliation(s)
- Patrick Laurette
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Sébastien Coassolo
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Guillaume Davidson
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Isabelle Michel
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Giovanni Gambi
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Wenjin Yao
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Pierre Sohier
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,Univ. Paris-Sud, Univ. Paris-Saclay, CNRS UMR3347, Orsay, France.,Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Mei Li
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Gabrielle Mengus
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France
| | - Lionel Larue
- INSERM U1021, Normal and Pathological Development of Melanocytes, Institut Curie, PSL Research University, Orsay, France.,Univ. Paris-Sud, Univ. Paris-Saclay, CNRS UMR3347, Orsay, France.,Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Irwin Davidson
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch Cédex, France. .,Equipes Labellisées Ligue Contre le Cancer, Paris, France.
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17
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Aras S, Saladi SV, Basuroy T, Marathe HG, Lorès P, de la Serna IL. BAF60A mediates interactions between the microphthalmia-associated transcription factor and the BRG1-containing SWI/SNF complex during melanocyte differentiation. J Cell Physiol 2018; 234:11780-11791. [PMID: 30515787 DOI: 10.1002/jcp.27840] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 11/07/2018] [Indexed: 01/10/2023]
Abstract
SWI/SNF chromatin remodeling enzymes are multisubunit complexes that contain one of two catalytic subunits, BRG1 or BRM and 9-11 additional subunits called BRG1 or BRM-associated factors (BAFs). BRG1 interacts with the microphthalmia-associated transcription factor (MITF) and is required for melanocyte development in vitro and in vivo. The subunits of SWI/SNF that mediate interactions between BRG1 and MITF have not been elucidated. Three mutually exclusive isoforms of a 60-kDa subunit (BAF60A, B, or C) often facilitate interactions with transcription factors during lineage specification. We tested the hypothesis that a BAF60 subunit promotes interactions between MITF and the BRG1-containing SWI/SNF complex. We found that MITF can physically interact with BAF60A, BAF60B, and BAF60C. The interaction between MITF and BAF60A required the basic helix-loop-helix domain of MITF. Recombinant BAF60A pulled down recombinant MITF, suggesting that the interaction can occur in the absence of other SWI/SNF subunits and other transcriptional regulators of the melanocyte lineage. Depletion of BAF60A in differentiating melanoblasts inhibited melanin synthesis and expression of MITF target genes. MITF promoted BAF60A recruitment to melanocyte-specific promoters, and BAF60A was required to promote BRG1 recruitment and chromatin remodeling. Thus, BAF60A promotes interactions between MITF and the SWI/SNF complex and is required for melanocyte differentiation.
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Affiliation(s)
- Shweta Aras
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio.,Department of Cancer Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Srinivas Vinod Saladi
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio.,Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, Massachusetts
| | - Tupa Basuroy
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Himangi G Marathe
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio.,Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York
| | - Patrick Lorès
- INSERM U1016, Institut Cochin/CNRS UMR8104/ Universite Paris Descartes, Faculte de Medecine Cochin, Paris, France
| | - Ivana L de la Serna
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
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18
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Fessé P, Qvarnström F, Nyman J, Hermansson I, Ahlgren J, Turesson I. UV-Radiation Response Proteins Reveal Undifferentiated Cutaneous Interfollicular Melanocytes with Hyperradiosensitivity to Differentiation at 0.05 Gy Radiotherapy Dose Fractions. Radiat Res 2018; 191:93-106. [PMID: 30407899 DOI: 10.1667/rr15078.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To date, the response activated in melanocytes by repeated genotoxic insults from radiotherapy has not been explored. We hypothesized that the molecular pathways involved in the response of melanocytes to ionizing radiation and ultraviolet radiation (UVR) are similar. Skin punch biopsies, not sun-exposed, were collected from prostate cancer patients before, as well as at 1 and 6.5 weeks after daily doses of 0.05-1.1 Gy. Interfollicular melanocytes were identified by ΔNp63- and eosin-periodic acid Schiff staining. Immunohistochemistry and immunofluorescence were performed to detect molecular markers of the melanocyte lineage. Melanocytes were negative for ΔNp63, and the number remained unchanged over the treatment period. At radiation doses as low as 0.05 Gy, melanocytes express higher protein levels of microphthalmia-associated transcription factor (MITF) and Bcl-2. Subsets of MITF- and Bcl-2-negative melanocytes were identified among interfollicular melanocytes in unexposed skin; the cell number in both subsets was reduced after irradiation in a way that indicates low-dose hyperradiosensitivity. A corresponding increase in MITF- and Bcl-2-positive cells was observed. PAX3 and SOX10 co-localized to some extent with MITF in unexposed skin, more so with radiation exposure. Low doses of ionizing radiation also intensified c-KIT and DCT staining. Nuclear p53 and p21 were undetectable in melanocytes. Apoptosis and proliferation could not be observed. In conclusion, undifferentiated interfollicular melanocytes were identified, and responded with differentiation in a hypersensitive manner at 0.05 Gy doses. Radioresistance regarding cell death was maintained up to fractionated doses of 1.1 Gy, applied for 7 weeks. The results suggest that the initial steps of melanin synthesis are common to ionizing radiation and UVR, and underline the importance of keratinocyte-melanocyte interaction behind hyperpigmentation and depigmentation to radiotherapy.
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Affiliation(s)
- Per Fessé
- a Centre for Research and Development, Uppsala University/Region Gävleborg, Gävle, Sweden.,b Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology, Uppsala University, Uppsala, Sweden
| | - Fredrik Qvarnström
- b Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology, Uppsala University, Uppsala, Sweden
| | - Jan Nyman
- c Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden and
| | - Ingegerd Hermansson
- c Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden and
| | - Johan Ahlgren
- d Department of Oncology, Faculty of Medicine and Health, Örebro University, Örebro Sweden
| | - Ingela Turesson
- b Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology, Uppsala University, Uppsala, Sweden
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19
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Wu Q, Fung AHY, Xu ML, Poon K, Liu EYL, Kong XP, Yao P, Xiong QP, Dong TTX, Tsim KWK. Microphthalmia-associated transcription factor up-regulates acetylcholinesterase expression during melanogenesis of murine melanoma cells. J Biol Chem 2018; 293:14417-14428. [PMID: 30076217 DOI: 10.1074/jbc.ra118.003729] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/29/2018] [Indexed: 11/06/2022] Open
Abstract
Acetylcholinesterase (AChE) hydrolyzes the neurotransmitter acetylcholine in neurons. However, AChE has been proposed to also have nonneuronal functions in different cell types. Here, we report that AChE is expressed in melanocytes and melanoma cells, and that the tetrameric (G4) form is the major AChE isoform in these cells. During melanogenesis of B16F10 murine melanoma cells, AChE levels decreased markedly. The differentiation of melanoma cells led to (i) an increase in melanin and tyrosinase, (ii) a change in intracellular cAMP levels, and (iii) a decrease in microphthalmia-associated transcription factor (MITF). We hypothesized that the regulation of AChE during melanogenesis is mediated by two transcription factors: cAMP-response element-binding protein (CREB) and MITF. In melanoma cells, exogenous cAMP suppressed AChE expression and the promoter activity of the ACHE gene. This suppression was mediated by a cAMP-response element (CRE) located on the ACHE promoter, as mutation of CRE relieved the suppression. In melanoma, MITF overexpression induced ACHE transcription, and mutation of an E-box site in human ACHE promoter blocked this induction. An AChE inhibitor greatly enhanced acetylcholine-mediated responses of melanogenic gene expression levels in vitro; however, this enhancement was not observed in the presence of agonists of the muscarinic acetylcholine receptor. These results indicate that ACHE transcription is regulated by cAMP-dependent signaling during melanogenesis of B16F10 cells, and the effect of this enzyme on melanin production suggests that it has a potential role in skin pigmentation.
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Affiliation(s)
- Qiyun Wu
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Aster H Y Fung
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Miranda L Xu
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Kaman Poon
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Etta Y L Liu
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Xiang P Kong
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and
| | - Ping Yao
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Qing P Xiong
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Tina T X Dong
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Karl W K Tsim
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and .,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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20
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Seberg HE, Van Otterloo E, Cornell RA. Beyond MITF: Multiple transcription factors directly regulate the cellular phenotype in melanocytes and melanoma. Pigment Cell Melanoma Res 2018. [PMID: 28649789 DOI: 10.1111/pcmr.12611] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
MITF governs multiple steps in the development of melanocytes, including specification from neural crest, growth, survival, and terminal differentiation. In addition, the level of MITF activity determines the phenotype adopted by melanoma cells, whether invasive, proliferative, or differentiated. However, MITF does not act alone. Here, we review literature on the transcription factors that co-regulate MITF-dependent genes. ChIP-seq studies have indicated that the transcription factors SOX10, YY1, and TFAP2A co-occupy subsets of regulatory elements bound by MITF in melanocytes. Analyses at single loci also support roles for LEF1, RB1, IRF4, and PAX3 acting in combination with MITF, while sequence motif analyses suggest that additional transcription factors colocalize with MITF at many melanocyte-specific regulatory elements. However, the precise biochemical functions of each of these MITF collaborators and their contributions to gene expression remain to be elucidated. Analogous to the transcriptional networks in morphogen-patterned tissues during embryogenesis, we anticipate that the level of MITF activity is controlled not only by the concentration of activated MITF, but also by additional transcription factors that either quantitatively or qualitatively influence the expression of MITF-target genes.
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Affiliation(s)
- Hannah E Seberg
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, USA
| | - Eric Van Otterloo
- SDM-Craniofacial Biology, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
| | - Robert A Cornell
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA, USA.,Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA, USA
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21
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Wu Q, Sharma S, Cui H, LeBlanc SE, Zhang H, Muthuswami R, Nickerson JA, Imbalzano AN. Targeting the chromatin remodeling enzyme BRG1 increases the efficacy of chemotherapy drugs in breast cancer cells. Oncotarget 2017; 7:27158-75. [PMID: 27029062 PMCID: PMC5053639 DOI: 10.18632/oncotarget.8384] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 03/16/2016] [Indexed: 12/31/2022] Open
Abstract
Brahma related gene product 1 (BRG1) is an ATPase that drives the catalytic activity of a subset of the mammalian SWI/SNF chromatin remodeling enzymes. BRG1 is overexpressed in most human breast cancer tumors without evidence of mutation and is required for breast cancer cell proliferation. We demonstrate that knockdown of BRG1 sensitized triple negative breast cancer cells to chemotherapeutic drugs used to treat breast cancer. An inhibitor of the BRG1 bromodomain had no effect on breast cancer cell viability, but an inhibitory molecule that targets the BRG1 ATPase activity recapitulated the increased drug efficacy observed in the presence of BRG1 knockdown. We further demonstrate that inhibition of BRG1 ATPase activity blocks the induction of ABC transporter genes by these chemotherapeutic drugs and that BRG1 binds to ABC transporter gene promoters. This inhibition increased intracellular concentrations of the drugs, providing a likely mechanism for the increased chemosensitivity. Since ABC transporters and their induction by chemotherapy drugs are a major cause of chemoresistance and treatment failure, these results support the idea that targeting the enzymatic activity of BRG1 would be an effective adjuvant therapy for breast cancer.
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Affiliation(s)
- Qiong Wu
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Soni Sharma
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India
| | - Hang Cui
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA.,Abace Biotech Co Ltd., Yi Zhuang Biomedical Park, BDA, Beijing, China
| | - Scott E LeBlanc
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Hong Zhang
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Rohini Muthuswami
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India
| | - Jeffrey A Nickerson
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, USA
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22
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Marathe HG, Watkins-Chow DE, Weider M, Hoffmann A, Mehta G, Trivedi A, Aras S, Basuroy T, Mehrotra A, Bennett DC, Wegner M, Pavan WJ, de la Serna IL. BRG1 interacts with SOX10 to establish the melanocyte lineage and to promote differentiation. Nucleic Acids Res 2017; 45:6442-6458. [PMID: 28431046 PMCID: PMC5499657 DOI: 10.1093/nar/gkx259] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 04/04/2017] [Indexed: 12/30/2022] Open
Abstract
Mutations in SOX10 cause neurocristopathies which display varying degrees of hypopigmentation. Using a sensitized mutagenesis screen, we identified Smarca4 as a modifier gene that exacerbates the phenotypic severity of Sox10 haplo-insufficient mice. Conditional deletion of Smarca4 in SOX10 expressing cells resulted in reduced numbers of cranial and ventral trunk melanoblasts. To define the requirement for the Smarca4 -encoded BRG1 subunit of the SWI/SNF chromatin remodeling complex, we employed in vitro models of melanocyte differentiation in which induction of melanocyte-specific gene expression is closely linked to chromatin alterations. We found that BRG1 was required for expression of Dct, Tyrp1 and Tyr, genes that are regulated by SOX10 and MITF and for chromatin remodeling at distal and proximal regulatory sites. SOX10 was found to physically interact with BRG1 in differentiating melanocytes and binding of SOX10 to the Tyrp1 distal enhancer temporally coincided with recruitment of BRG1. Our data show that SOX10 cooperates with MITF to facilitate BRG1 binding to distal enhancers of melanocyte-specific genes. Thus, BRG1 is a SOX10 co-activator, required to establish the melanocyte lineage and promote expression of genes important for melanocyte function.
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Affiliation(s)
- Himangi G Marathe
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Dawn E Watkins-Chow
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4472, USA
| | - Matthias Weider
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Alana Hoffmann
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Gaurav Mehta
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Archit Trivedi
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Shweta Aras
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Tupa Basuroy
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Aanchal Mehrotra
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Dorothy C Bennett
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - William J Pavan
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4472, USA
| | - Ivana L de la Serna
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
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23
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Tfe3 and Tfeb Transcriptionally Regulate Peroxisome Proliferator-Activated Receptor γ2 Expression in Adipocytes and Mediate Adiponectin and Glucose Levels in Mice. Mol Cell Biol 2017; 37:MCB.00608-16. [PMID: 28483914 DOI: 10.1128/mcb.00608-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 04/19/2017] [Indexed: 12/28/2022] Open
Abstract
Members of the MiT transcription factor family are pivotal regulators of several lineage-selective differentiation programs. We show that two of these, Tfeb and Tfe3, control the regulator of adipogenesis, peroxisome proliferator-activated receptor γ2 (Pparγ2). Knockdown of Tfeb or Tfe3 expression during in vitro adipogenesis causes dramatic downregulation of Pparγ2 expression as well as adipogenesis. Additionally, we found that these factors regulate Pparγ2 in mature adipocytes. Next, we demonstrated that Tfeb and Tfe3 act directly by binding to consensus E-boxes within the Pparγ transcriptional regulatory region. This transcriptional control also exists in vivo, as we discovered that wild-type mice in the fed state increased their expression of Tfe3, Tf3b, and Pparγ in white adipose tissue. Furthermore, Tfe3 knockout (Tfe3KO) mice in the fed state failed to upregulate Pparγ and the adiponectin gene, a Pparγ-dependent gene, confirming the in vivo role for Tfe3. Lastly, we found that blood glucose is elevated and serum adiponectin levels are suppressed in the Tfe3KO mice, indicating that the Tfe3/Tfeb/Pparγ2 axis may contribute to whole-body energy balance. Thus, we offer new insights into the upstream regulation of Pparγ by Tfe3/Tf3b and propose that targeting these transcription factors may offer opportunities to complement existing approaches for the treatment of diseases that have dysregulated energy metabolism.
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24
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The master role of microphthalmia-associated transcription factor in melanocyte and melanoma biology. J Transl Med 2017; 97:649-656. [PMID: 28263292 DOI: 10.1038/labinvest.2017.9] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 01/07/2017] [Accepted: 01/10/2017] [Indexed: 12/20/2022] Open
Abstract
Certain transcription factors have vital roles in lineage development, including specification of cell types and control of differentiation. Microphthalmia-associated transcription factor (MITF) is a key transcription factor for melanocyte development and differentiation. MITF regulates expression of numerous pigmentation genes to promote melanocyte differentiation, as well as fundamental genes for maintaining cell homeostasis, including genes encoding proteins involved in apoptosis (eg, BCL2) and the cell cycle (eg, CDK2). Loss-of-function mutations of MITF cause Waardenburg syndrome type IIA, whose phenotypes include depigmentation due to melanocyte loss, whereas amplification or specific mutation of MITF can be an oncogenic event that is seen in a subset of familial or sporadic melanomas. In this article, we review basic features of MITF biological function and highlight key unresolved questions regarding this remarkable transcription factor.
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25
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Wu Q, Lian JB, Stein JL, Stein GS, Nickerson JA, Imbalzano AN. The BRG1 ATPase of human SWI/SNF chromatin remodeling enzymes as a driver of cancer. Epigenomics 2017; 9:919-931. [PMID: 28521512 PMCID: PMC5705788 DOI: 10.2217/epi-2017-0034] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mammalian SWI/SNF enzymes are ATP-dependent remodelers of chromatin structure. These multisubunit enzymes are heterogeneous in composition; there are two catalytic ATPase subunits, BRM and BRG1, that are mutually exclusive, and additional subunits are incorporated in a combinatorial manner. Recent findings indicate that approximately 20% of human cancers contain mutations in SWI/SNF enzyme subunits, leading to the conclusion that the enzyme subunits are critical tumor suppressors. However, overexpression of specific subunits without apparent mutation is emerging as an alternative mechanism by which cellular transformation may occur. Here we highlight recent evidence linking elevated expression of the BRG1 ATPase to tissue-specific cancers and work suggesting that inhibiting BRG1 may be an effective therapeutic strategy.
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Affiliation(s)
- Qiong Wu
- Department of Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Jane B Lian
- Department of Biochemistry, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA
| | - Janet L Stein
- Department of Biochemistry, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA
| | - Gary S Stein
- Department of Biochemistry, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA
| | - Jeffrey A Nickerson
- Department of Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Anthony N Imbalzano
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
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26
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Laurette P, Koludrovic D, Coassolo S, Davidson I. [Epigenetic regulation of gene expression in malignant melanoma]. Biol Aujourdhui 2017; 210:283-295. [PMID: 28327285 DOI: 10.1051/jbio/2016028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Indexed: 06/06/2023]
Abstract
Malignant melanoma is a highly aggressive cancer with a propensity for early metastasis. Melanocyte transformation results predominantly from oncogenic mutations in BRAF, NRAS or NF1 leading to constitutive activation of the MAP kinase pathway driving cell proliferation and second site mutations such as loss of CDKN1A, or PTEN or activating mutations in the beta-catenin pathway that allow escape from oncogene induced senescence. Nevertheless, irrespective of the nature of the driver mutations, melanoma cell physiology is strongly regulated by transcription factors and epigenetic mechanisms. MITF (Microphthalmia-associated Transcription Factor) and SOX10 are two major transcription factors that regulate both normal melanocyte and melanoma cell physiology. Using a combination of mouse genetics, biochemistry and high throughput genomics we have identified cofactors for MITF and addressed the mechanisms by which MITF, SOX10 and their cofactors regulate gene expression in melanocytes and melanoma.
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27
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28
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Developmental mechanisms of stripe patterns in rodents. Nature 2016; 539:518-523. [PMID: 27806375 DOI: 10.1038/nature20109] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 09/16/2016] [Indexed: 11/08/2022]
Abstract
Mammalian colour patterns are among the most recognizable characteristics found in nature and can have a profound impact on fitness. However, little is known about the mechanisms underlying the formation and subsequent evolution of these patterns. Here we show that, in the African striped mouse (Rhabdomys pumilio), periodic dorsal stripes result from underlying differences in melanocyte maturation, which give rise to spatial variation in hair colour. We identify the transcription factor ALX3 as a regulator of this process. In embryonic dorsal skin, patterned expression of Alx3 precedes pigment stripes and acts to directly repress Mitf, a master regulator of melanocyte differentiation, thereby giving rise to light-coloured hair. Moreover, Alx3 is upregulated in the light stripes of chipmunks, which have independently evolved a similar dorsal pattern. Our results show a previously undescribed mechanism for modulating spatial variation in hair colour and provide insights into how phenotypic novelty evolves.
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29
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Welsh SJ, Rizos H. Melanocyte reprogramming requires chromatin and transcription remodelling. Pigment Cell Melanoma Res 2016; 29:260-1. [PMID: 26813636 DOI: 10.1111/pcmr.12457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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LeBlanc SE, Wu Q, Lamba P, Sif S, Imbalzano AN. Promoter-enhancer looping at the PPARγ2 locus during adipogenic differentiation requires the Prmt5 methyltransferase. Nucleic Acids Res 2016; 44:5133-47. [PMID: 26935580 PMCID: PMC4914087 DOI: 10.1093/nar/gkw129] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 02/22/2016] [Indexed: 01/05/2023] Open
Abstract
PPARγ2 is a critical lineage-determining transcription factor that is essential for adipogenic differentiation. Here we report characterization of the three-dimensional structure of the PPARγ2 locus after the onset of adipogenic differentiation and the mechanisms by which it forms. We identified a differentiation-dependent loop between the PPARγ2 promoter and an enhancer sequence 10 kb upstream that forms at the onset of PPARγ2 expression. The arginine methyltransferase Prmt5 was required for loop formation, and overexpression of Prmt5 resulted in premature loop formation and earlier onset of PPARγ2 expression. Kinetic studies of regulatory factor interactions at the PPARγ2 promoter and enhancer revealed enhanced interaction of Prmt5 with the promoter that preceded stable association of Prmt5 with enhancer sequences. Prmt5 knockdown prevented binding of both MED1, a subunit of Mediator complex that facilitates enhancer–promoter interactions, and Brg1, the ATPase of the mammalian SWI/SNF chromatin remodeling enzyme required for PPARγ2 activation and adipogenic differentiation. The data indicate a dynamic association of Prmt5 with the regulatory sequences of the PPARγ2 gene that facilitates differentiation-dependent, three-dimensional organization of the locus. In addition, other differentiation-specific, long-range chromatin interactions showed Prmt5-dependence, indicating a more general role for Prmt5 in mediating higher-order chromatin connections in differentiating adipocytes.
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Affiliation(s)
- Scott E LeBlanc
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Qiong Wu
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Pallavi Lamba
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Saïd Sif
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, Qatar Department of Internal Medicine, The Ohio State University College of Medicine, 395 W. 12th Avenue, Third Floor, Columbus, OH 43210, USA
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
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31
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Mehta G, Kumarasamy S, Wu J, Walsh A, Liu L, Williams K, Joe B, de la Serna IL. MITF interacts with the SWI/SNF subunit, BRG1, to promote GATA4 expression in cardiac hypertrophy. J Mol Cell Cardiol 2015; 88:101-10. [PMID: 26388265 PMCID: PMC4640968 DOI: 10.1016/j.yjmcc.2015.09.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 09/03/2015] [Accepted: 09/17/2015] [Indexed: 11/26/2022]
Abstract
The transcriptional regulation of pathological cardiac hypertrophy involves the interplay of transcription factors and chromatin remodeling enzymes. The Microphthalmia-Associated Transcription Factor (MITF) is highly expressed in cardiomyocytes and is required for cardiac hypertrophy. However, the transcriptional mechanisms by which MITF promotes cardiac hypertrophy have not been elucidated. In this study, we tested the hypothesis that MITF promotes cardiac hypertrophy by activating transcription of pro-hypertrophy genes through interactions with the SWI/SNF chromatin remodeling complex. In an in vivo model of cardiac hypertrophy, expression of MITF and the BRG1 subunit of the SWI/SNF complex increased coordinately in response to pressure overload. Expression of MITF and BRG1 also increased in vitro when cardiomyocytes were stimulated with angiotensin II or a β-adrenergic agonist. Both MITF and BRG1 were required to increase cardiomyocyte size and activate expression of hypertrophy markers in response to β-adrenergic stimulation. We detected physical interactions between MITF and BRG1 in cardiomyocytes and found that they cooperate to regulate expression of a pro-hypertrophic transcription factor, GATA4. Our data show that MITF binds to the E box element in the GATA4 promoter and facilitates recruitment of BRG1. This is associated with enhanced expression of the GATA4 gene as evidenced by increased Histone3 lysine4 tri-methylation (H3K4me3) on the GATA4 promoter. Thus, in hypertrophic cardiomyoctes, MITF is a key transcriptional activator of a pro-hypertrophic gene, GATA4, and this regulation is dependent upon the BRG1 component of the SWI/SNF complex.
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Affiliation(s)
- Gaurav Mehta
- University of Toledo College of Medicine and Life Sciences, Department of Biochemistry and Cancer Biology, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Sivarajan Kumarasamy
- University of Toledo College of Medicine and Life Sciences, Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology and Pharmacology, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Jian Wu
- University of Toledo College of Medicine and Life Sciences, Department of Biochemistry and Cancer Biology, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Aaron Walsh
- University of Toledo College of Medicine and Life Sciences, Department of Biochemistry and Cancer Biology, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Lijun Liu
- University of Toledo College of Medicine and Life Sciences, Department of Biochemistry and Cancer Biology, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Kandace Williams
- University of Toledo College of Medicine and Life Sciences, Department of Biochemistry and Cancer Biology, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Bina Joe
- University of Toledo College of Medicine and Life Sciences, Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology and Pharmacology, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Ivana L de la Serna
- University of Toledo College of Medicine and Life Sciences, Department of Biochemistry and Cancer Biology, 3035 Arlington Ave, Toledo, OH 43614, USA.
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Sarkar D, Leung EY, Baguley BC, Finlay GJ, Askarian-Amiri ME. Epigenetic regulation in human melanoma: past and future. Epigenetics 2015; 10:103-21. [PMID: 25587943 PMCID: PMC4622872 DOI: 10.1080/15592294.2014.1003746] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The development and progression of melanoma have been attributed to independent or combined genetic and epigenetic events. There has been remarkable progress in understanding melanoma pathogenesis in terms of genetic alterations. However, recent studies have revealed a complex involvement of epigenetic mechanisms in the regulation of gene expression, including methylation, chromatin modification and remodeling, and the diverse activities of non-coding RNAs. The roles of gene methylation and miRNAs have been relatively well studied in melanoma, but other studies have shown that changes in chromatin status and in the differential expression of long non-coding RNAs can lead to altered regulation of key genes. Taken together, they affect the functioning of signaling pathways that influence each other, intersect, and form networks in which local perturbations disturb the activity of the whole system. Here, we focus on how epigenetic events intertwine with these pathways and contribute to the molecular pathogenesis of melanoma.
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Key Words
- 5hmC, 5-hydroxymethylcytosine
- 5mC, 5-methylcytosine
- ACE, angiotensin converting enzyme
- ANCR, anti-differentiation non-coding RNA
- ANRIL, antisense noncoding RNA in INK4 locus
- ASK1, apoptosis signal-regulating kinase 1
- ATRA, all-trans retinoic acid
- BANCR, BRAF-activated non-coding RNA
- BCL-2, B-cell lymphoma 2
- BRAF, B-Raf proto-oncogene, serine/threonine kinase
- BRG1, ATP-dependent helicase SMARCA4
- CAF-1, chromatin assembly factor-1
- CBX7, chromobox homolog 7
- CCND1, cyclin D1
- CD28, cluster of differentiation 28
- CDK, cyclin-dependent kinase
- CDKN2A/B, cyclin-dependent kinase inhibitor 2A/B
- CHD8, chromodomain-helicase DNA-binding protein 8
- CREB, cAMP response element-binding protein
- CUDR, cancer upregulated drug resistant
- Cdc6, cell division cycle 6
- DNA methylation/demethylation
- DNMT, DNA methyltransferase
- EMT, epithelial-mesenchymal transition
- ERK, extracellular signal-regulated kinase
- EZH2, enhancer of zeste homolog 2
- GPCRs, G-protein coupled receptors
- GSK3a, glycogen synthase kinase 3 α
- GWAS, genome-wide association study
- HDAC, histone deacetylase
- HOTAIR, HOX antisense intergenic RNA
- IAP, inhibitor of apoptosis
- IDH2, isocitrate dehydrogenase
- IFN, interferon, interleukin 23
- JNK, Jun N-terminal kinase
- Jak/STAT, Janus kinase/signal transducer and activator of transcription
- MAFG, v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog G
- MALAT1, metastasis-associated lung adenocarcinoma transcript 1
- MAPK, mitogen-activated protein kinase
- MC1R, melanocortin-1 receptor
- MGMT, O6-methylguanine-DNA methyltransferase
- MIF, macrophage migration inhibitory factor
- MITF, microphthalmia-associated transcription factor
- MRE, miRNA recognition element
- MeCP2, methyl CpG binding protein 2
- NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells
- NOD, nucleotide-binding and oligomerization domain
- PBX, pre-B-cell leukemia homeobox
- PEDF, pigment epithelium derived factor
- PI3K, phosphatidylinositol-4, 5-bisphosphate 3-kinase
- PIB5PA, phosphatidylinositol-4, 5-biphosphate 5-phosphatase A
- PKA, protein kinase A
- PRC, polycomb repressor complex
- PSF, PTB associated splicing factor
- PTB, polypyrimidine tract-binding
- PTEN, phosphatase and tensin homolog
- RARB, retinoic acid receptor-β2
- RASSF1A, Ras association domain family 1A
- SETDB1, SET Domain, bifurcated 1
- SPRY4, Sprouty 4
- STAU1, Staufen1
- SWI/SNF, SWItch/Sucrose Non-Fermentable
- TCR, T-cell receptor
- TET, ten eleven translocase
- TGF β, transforming growth factor β
- TINCR, tissue differentiation-inducing non-protein coding RNA
- TOR, target of rapamycin
- TP53, tumor protein 53
- TRAF6, TNF receptor-associated factor 6
- UCA1, urothelial carcinoma-associated 1
- ceRNA, competitive endogenous RNAs
- chromatin modification
- chromatin remodeling
- epigenetics
- gene regulation
- lncRNA, long ncRNA
- melanoma
- miRNA, micro RNA
- ncRNA, non-coding RNA
- ncRNAs
- p14ARF, p14 alternative reading frame
- p16INK4a, p16 inhibitor of CDK4
- pRB, retinoblastoma protein
- snoRNA, small nucleolar RNA
- α-MSHm, α-melanocyte stimulating hormone
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Affiliation(s)
- Debina Sarkar
- a Auckland Cancer Society Research Center ; University of Auckland ; Auckland , New Zealand
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33
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Gallagher SJ, Tiffen JC, Hersey P. Histone Modifications, Modifiers and Readers in Melanoma Resistance to Targeted and Immune Therapy. Cancers (Basel) 2015; 7:1959-82. [PMID: 26426052 PMCID: PMC4695870 DOI: 10.3390/cancers7040870] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/17/2015] [Accepted: 09/18/2015] [Indexed: 02/06/2023] Open
Abstract
The treatment of melanoma has been revolutionized by new therapies targeting MAPK signaling or the immune system. Unfortunately these therapies are hindered by either primary resistance or the development of acquired resistance. Resistance mechanisms involving somatic mutations in genes associated with resistance have been identified in some cases of melanoma, however, the cause of resistance remains largely unexplained in other cases. The importance of epigenetic factors targeting histones and histone modifiers in driving the behavior of melanoma is only starting to be unraveled and provides significant opportunity to combat the problems of therapy resistance. There is also an increasing ability to target these epigenetic changes with new drugs that inhibit these modifications to either prevent or overcome resistance to both MAPK inhibitors and immunotherapy. This review focuses on changes in histones, histone reader proteins and histone positioning, which can mediate resistance to new therapeutics and that can be targeted for future therapies.
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Affiliation(s)
- Stuart J Gallagher
- Melanoma Immunology and Oncology Group, Centenary Institute, University of Sydney, Camperdown 2050, Australia.
- Melanoma Institute Australia, Crow's Nest 2065, Sydney, Australia.
| | - Jessamy C Tiffen
- Melanoma Immunology and Oncology Group, Centenary Institute, University of Sydney, Camperdown 2050, Australia.
- Melanoma Institute Australia, Crow's Nest 2065, Sydney, Australia.
| | - Peter Hersey
- Melanoma Immunology and Oncology Group, Centenary Institute, University of Sydney, Camperdown 2050, Australia.
- Melanoma Institute Australia, Crow's Nest 2065, Sydney, Australia.
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34
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Wellbrock C, Arozarena I. Microphthalmia-associated transcription factor in melanoma development and MAP-kinase pathway targeted therapy. Pigment Cell Melanoma Res 2015; 28:390-406. [PMID: 25818589 PMCID: PMC4692100 DOI: 10.1111/pcmr.12370] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 03/16/2015] [Indexed: 12/12/2022]
Abstract
Malignant melanoma is a neoplasm of melanocytes, and the microphthalmia-associated transcription factor (MITF) is essential for the existence of melanocytes. MITF's relevance for this cell lineage is maintained in melanoma, where it is an important regulator of survival and balances melanoma cell proliferation with terminal differentiation (pigmentation). The MITF gene is amplified in ~20% of melanomas and MITF mutation can predispose to melanoma development. Furthermore, the regulation of MITF expression and function is strongly linked to the BRAF/MEK/ERK/MAP-kinase (MAPK) pathway, which is deregulated in >90% of melanomas and central target of current therapies. MITF expression in melanoma is heterogeneous, and recent findings highlight the relevance of this heterogeneity for the response of melanoma to MAPK pathway targeting drugs, as well as for MITF's role in melanoma progression. This review aims to provide an updated overview on the regulation of MITF function and plasticity in melanoma with a focus on its link to MAPK signaling.
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Affiliation(s)
- Claudia Wellbrock
- Manchester Cancer Research CentreWellcome Trust Centre for Cell Matrix ResearchFaculty of Life SciencesThe University of ManchesterManchesterUK
| | - Imanol Arozarena
- Manchester Cancer Research CentreWellcome Trust Centre for Cell Matrix ResearchFaculty of Life SciencesThe University of ManchesterManchesterUK
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Laurette P, Strub T, Koludrovic D, Keime C, Le Gras S, Seberg H, Van Otterloo E, Imrichova H, Siddaway R, Aerts S, Cornell RA, Mengus G, Davidson I. Transcription factor MITF and remodeller BRG1 define chromatin organisation at regulatory elements in melanoma cells. eLife 2015; 4. [PMID: 25803486 PMCID: PMC4407272 DOI: 10.7554/elife.06857] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 03/24/2015] [Indexed: 12/17/2022] Open
Abstract
Microphthalmia-associated transcription factor (MITF) is the master regulator of the melanocyte lineage. To understand how MITF regulates transcription, we used tandem affinity purification and mass spectrometry to define a comprehensive MITF interactome identifying novel cofactors involved in transcription, DNA replication and repair, and chromatin organisation. We show that MITF interacts with a PBAF chromatin remodelling complex comprising BRG1 and CHD7. BRG1 is essential for melanoma cell proliferation in vitro and for normal melanocyte development in vivo. MITF and SOX10 actively recruit BRG1 to a set of MITF-associated regulatory elements (MAREs) at active enhancers. Combinations of MITF, SOX10, TFAP2A, and YY1 bind between two BRG1-occupied nucleosomes thus defining both a signature of transcription factors essential for the melanocyte lineage and a specific chromatin organisation of the regulatory elements they occupy. BRG1 also regulates the dynamics of MITF genomic occupancy. MITF-BRG1 interplay thus plays an essential role in transcription regulation in melanoma.
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Affiliation(s)
- Patrick Laurette
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Thomas Strub
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Dana Koludrovic
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Céline Keime
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Stéphanie Le Gras
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Hannah Seberg
- University of Iowa College of Medicine, Iowa City, United States
| | | | - Hana Imrichova
- Laboratory of Computational Biology, Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - Robert Siddaway
- Arthur and Sonia Labatt Brain Tumor Research Centre, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Canada
| | - Stein Aerts
- Laboratory of Computational Biology, Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - Robert A Cornell
- University of Iowa College of Medicine, Iowa City, United States
| | - Gabrielle Mengus
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Irwin Davidson
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, France
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Mehrotra A, Mehta G, Aras S, Trivedi A, de la Serna IL. SWI/SNF chromatin remodeling enzymes in melanocyte differentiation and melanoma. Crit Rev Eukaryot Gene Expr 2015; 24:151-61. [PMID: 24940768 DOI: 10.1615/critreveukaryotgeneexpr.2014007882] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Epidermal melanocytes are pigment-producing cells derived from the neural crest that protects skin from the damaging effects of solar radiation. Malignant melanoma, a highly aggressive cancer, arises from melanocytes. SWI/SNF enzymes are multiprotein complexes that remodel chromatin structure and have extensive roles in cellular differentiation. Components of the complex have been found to be mutated or lost in several human cancers. This review focuses on studies that implicate SWI/SNF enzymes in melanocyte differentiation and in melanoma.
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Affiliation(s)
- A Mehrotra
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - G Mehta
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - S Aras
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - A Trivedi
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - I L de la Serna
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH
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Abstract
Current models of melanoma propose that transition from the proliferative to the invasive stages of tumor development involves a dynamic and reversible switch in cell phenotype. The almost mutually exclusive proliferative and invasive phenotypes are defined by distinct gene expression signatures, which are themselves controlled by the level of functional MITF protein present in the cell. Recently, new signaling pathways and transcription factors that regulate MITF expression have been defined, and high throughput genomics have identified novel MITF target genes. MITF acts both as a transcription activator to promote expression of genes involved in cell cycle, but also as a transcriptional repressor of genes involved in invasion. A novel human germline mutation in MITF has been identified that blocks its sumoylation, thereby altering its transcriptional properties and conferring an increased risk of melanoma. These new studies depict an ever more complex function for MITF in melanoma.
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Affiliation(s)
- Dana Koludrovic
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UDS, 1 Rue Laurent Fries, 67404 Illkirch Cédex, France
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Harris ML, Buac K, Shakhova O, Hakami RM, Wegner M, Sommer L, Pavan WJ. A dual role for SOX10 in the maintenance of the postnatal melanocyte lineage and the differentiation of melanocyte stem cell progenitors. PLoS Genet 2013; 9:e1003644. [PMID: 23935512 PMCID: PMC3723529 DOI: 10.1371/journal.pgen.1003644] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 06/01/2013] [Indexed: 11/18/2022] Open
Abstract
During embryogenesis, the transcription factor, Sox10, drives the survival and differentiation of the melanocyte lineage. However, the role that Sox10 plays in postnatal melanocytes is not established. We show in vivo that melanocyte stem cells (McSCs) and more differentiated melanocytes express SOX10 but that McSCs remain undifferentiated. Sox10 knockout (Sox10(fl); Tg(Tyr::CreER)) results in loss of both McSCs and differentiated melanocytes, while overexpression of Sox10 (Tg(DctSox10)) causes premature differentiation and loss of McSCs, leading to hair graying. This suggests that levels of SOX10 are key to normal McSC function and Sox10 must be downregulated for McSC establishment and maintenance. We examined whether the mechanism of Tg(DctSox10) hair graying is through increased expression of Mitf, a target of SOX10, by asking if haploinsufficiency for Mitf (Mitf(vga9) ) can rescue hair graying in Tg(DctSox10) animals. Surprisingly, Mitf(vga9) does not mitigate but exacerbates Tg(DctSox10) hair graying suggesting that MITF participates in the negative regulation of Sox10 in McSCs. These observations demonstrate that while SOX10 is necessary to maintain the postnatal melanocyte lineage it is simultaneously prevented from driving differentiation in the McSCs. This data illustrates how tissue-specific stem cells can arise from lineage-specified precursors through the regulation of the very transcription factors important in defining that lineage.
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Affiliation(s)
- Melissa L. Harris
- Genetic Disease Research Branch, National Human Genome Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kristina Buac
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Olga Shakhova
- Cell and Developmental Biology, Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Ramin M. Hakami
- School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia, United States of America
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lukas Sommer
- Cell and Developmental Biology, Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - William J. Pavan
- Genetic Disease Research Branch, National Human Genome Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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SWI/SNF enzymes promote SOX10- mediated activation of myelin gene expression. PLoS One 2013; 8:e69037. [PMID: 23874858 PMCID: PMC3712992 DOI: 10.1371/journal.pone.0069037] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 06/04/2013] [Indexed: 12/21/2022] Open
Abstract
SOX10 is a Sry-related high mobility (HMG)-box transcriptional regulator that promotes differentiation of neural crest precursors into Schwann cells, oligodendrocytes, and melanocytes. Myelin, formed by Schwann cells in the peripheral nervous system, is essential for propagation of nerve impulses. SWI/SNF complexes are ATP dependent chromatin remodeling enzymes that are critical for cellular differentiation. It was recently demonstrated that the BRG1 subunit of SWI/SNF complexes activates SOX10 expression and also interacts with SOX10 to activate expression of OCT6 and KROX20, two transcriptional regulators of Schwann cell differentiation. To determine the requirement for SWI/SNF enzymes in the regulation of genes that encode components of myelin, which are downstream of these transcriptional regulators, we introduced SOX10 into fibroblasts that inducibly express dominant negative versions of the SWI/SNF ATPases, BRM or BRG1. Dominant negative BRM and BRG1 have mutations in the ATP binding site and inhibit gene activation events that require SWI/SNF function. Ectopic expression of SOX10 in cells derived from NIH 3T3 fibroblasts led to the activation of the endogenous Schwann cell specific gene, myelin protein zero (MPZ) and the gene that encodes myelin basic protein (MBP). Thus, SOX10 reprogrammed these cells into myelin gene expressing cells. Ectopic expression of KROX20 was not sufficient for activation of these myelin genes. However, KROX20 together with SOX10 synergistically activated MPZ and MBP expression. Dominant negative BRM and BRG1 abrogated SOX10 mediated activation of MPZ and MBP and synergistic activation of these genes by SOX10 and KROX20. SOX10 was required to recruit BRG1 to the MPZ locus. Similarly, in immortalized Schwann cells, BRG1 recruitment to SOX10 binding sites at the MPZ locus was dependent on SOX10 and expression of dominant negative BRG1 inhibited expression of MPZ and MBP in these cells. Thus, SWI/SNF enzymes cooperate with SOX10 to directly activate genes that encode components of peripheral myelin.
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Saladi SV, Wong PG, Trivedi AR, Marathe HG, Keenen B, Aras S, Liew ZQ, Setaluri V, de la Serna IL. BRG1 promotes survival of UV-irradiated melanoma cells by cooperating with MITF to activate the melanoma inhibitor of apoptosis gene. Pigment Cell Melanoma Res 2013; 26:377-91. [PMID: 23480510 PMCID: PMC3633630 DOI: 10.1111/pcmr.12088] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 03/02/2013] [Indexed: 01/19/2023]
Abstract
Microphthalmia-associated transcription factor (MITF) is a survival factor in melanocytes and melanoma cells. MITF regulates expression of antiapoptotic genes and promotes lineage-specific survival in response to ultraviolet (UV) radiation and to chemotherapeutics. SWI/SNF chromatin-remodeling enzymes interact with MITF to regulate MITF target gene expression. We determined that the catalytic subunit, BRG1, of the SWI/SNF complex protects melanoma cells against UV-induced death. BRG1 prevents apoptosis in UV-irradiated melanoma cells by activating expression of the melanoma inhibitor of apoptosis (ML-IAP). Down-regulation of ML-IAP compromises BRG1-mediated survival of melanoma cells in response to UV radiation. BRG1 regulates ML-IAP expression by cooperating with MITF to promote transcriptionally permissive chromatin structure on the ML-IAP promoter. The alternative catalytic subunit, BRM, and the BRG1-associated factor, BAF180, were found to be dispensable for elevated expression of ML-IAP in melanoma cells. Thus, we illuminate a lineage-specific mechanism by which a specific SWI/SNF subunit, BRG1, modulates the cellular response to DNA damage by regulating an antiapoptotic gene and implicate this subunit of the SWI/SNF complex in mediating the prosurvival function of MITF.
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Affiliation(s)
- Srinivas V Saladi
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH, USA
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41
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Ondrušová L, Vachtenheim J, Réda J, Žáková P, Benková K. MITF-independent pro-survival role of BRG1-containing SWI/SNF complex in melanoma cells. PLoS One 2013; 8:e54110. [PMID: 23349796 PMCID: PMC3547967 DOI: 10.1371/journal.pone.0054110] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 12/10/2012] [Indexed: 11/20/2022] Open
Abstract
Metastasized malignant melanoma has a poor prognosis because of its intrinsic resistance to chemotherapy and radiotherapy. The central role in the melanoma transcriptional network has the transcription factor MITF (microphthalmia-associated transcription factor). It has been shown recently that the expression of MITF and some of its target genes require the SWI/SNF chromatin remodeling complex. Here we demonstrate that survival of melanoma cells requires functional SWI/SNF complex not only by supporting expression of MITF and its targets and but also by activating expression of prosurvival proteins not directly regulated by MITF. Microarray analysis revealed that besides the MITF-driven genes, expression of proteins like osteopontin, IGF1, TGFß2 and survivin, the factors known to be generally associated with progression of tumors and the antiapoptotic properties, were reduced in acute BRG1-depleted 501mel cells. Western blots and RT-PCR confirmed the microarray findings. These proteins have been verified to be expressed independently of MITF, because MITF depletion did not impair their expression. Because these genes are not regulated by MITF, the data suggests that loss of BRG1-based SWI/SNF complexes negatively affects survival pathways beyond the MITF cascade. Immunohistochemistry showed high expression of both BRM and BRG1 in primary melanomas. Exogenous CDK2, osteopontin, or IGF1 each alone partly relieved the block of proliferation imposed by BRG1 depletion, implicating that more factors, besides the MITF target genes, are involved in melanoma cell survival. Together these results demonstrate an essential role of SWI/SNF for the expression of MITF-dependent and MITF-independent prosurvival factors in melanoma cells and suggest that SWI/SNF may be a potential and effective target in melanoma therapy.
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Affiliation(s)
- Lubica Ondrušová
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Jiri Vachtenheim
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- * E-mail:
| | - Jiri Réda
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Petra Žáková
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Kamila Benková
- Department of Pathology, Hospital Bulovka, Prague, Czech Republic
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42
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Mou Y, Jiang X, Du Y, Xue L. Intelligent bioengineering in vitiligo treatment: Transdermal protein transduction of melanocyte-lineage-specific genes. Med Hypotheses 2012; 79:786-9. [DOI: 10.1016/j.mehy.2012.08.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 08/18/2012] [Accepted: 08/25/2012] [Indexed: 11/16/2022]
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Botchkarev VA, Gdula MR, Mardaryev AN, Sharov AA, Fessing MY. Epigenetic regulation of gene expression in keratinocytes. J Invest Dermatol 2012; 132:2505-21. [PMID: 22763788 PMCID: PMC3650472 DOI: 10.1038/jid.2012.182] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Nucleus is a complex and highly compartmentalized organelle, which organization undergoes major changes during cell differentiation allowing cells to become specialized and fulfill their functions.During terminal differentiation of the epidermal keratinocytes, nucleus undergoes programmed transformation from active status, associated with execution of the genetic programs of cornification and epidermal barrier formation, to fully inactive condition and becomes a part of the keratinized cells of the cornified layer. Tremendous progress achieved within the last two decades in understanding the biology of the nucleus and epigenetic mechanisms controlling gene expression allowed defining several levels in the regulation of cell differentiation-associated gene expression programs, including an accessibility of the gene regulatory regions to DNA-protein interactions, covalent DNA and histone modifications and ATP-dependent chromatin remodeling, as well as higher-order chromatin remodeling and nuclear compartmentalization of the genes and transcription machinery. Here, we integrate our current knowledge of the mechanisms controlling gene expression during terminal keratinocyte differentiation with distinct levels of chromatin organization and remodeling. We also propose the directions to further explore the role of epigenetic mechanisms and their interactions with other regulatory systems in the control of keratinocyte differentiation in normal and diseased skin.
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Levy C, Fisher DE. Dual roles of lineage restricted transcription factors: the case of MITF in melanocytes. Transcription 2012; 2:19-22. [PMID: 21326905 DOI: 10.4161/trns.2.1.13650] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 11/19/2022] Open
Abstract
Microphthalmia-associated Transcription Factor, MITF, is a master regulator of melanocyte development, differentiation, migration, and survival.(1) A broad collection of studies have indicated that MITF directly regulates the transcription of genes involved in pigmentation, which are selective to the melanocyte lineage. In addition, MITF controls expression of genes which are expressed in multiple cell lineages, and may also play differential roles in activating vs. maintaining gene expression patterns. In this Point of View article, we discuss lineage restricted transcription factor activation of both tissue-specific and ubiquitously expressed genes using melanocytes and MITF as a model system that may eventually provide insights into such processes in multiple cell lineages.
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Affiliation(s)
- Carmit Levy
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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45
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He L, Liu H, Tang L. SWI/SNF chromatin remodeling complex: a new cofactor in reprogramming. Stem Cell Rev Rep 2012; 8:128-36. [PMID: 21655945 DOI: 10.1007/s12015-011-9285-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Induced pluripotent stem (iPS) cells can be derived from somatic cells. Four key factors are required in this process including Oct4, Sox2, Klf4 and c-Myc. Ectopic expression of these four factors in somatic cells leads to reprogramming. Recent studies show that the SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex plays critical roles in reprogramming of somatic cells and maintaining the pluripotency of stem cells. The possible mechanism is that SWI/SNF enhances the binding activity of reprogramming factors to pluripotent gene promoters and thus increases the reprogramming efficiency. Here, we review these recent advances and discuss how SWI/SNF plays a role in reprogramming. Understanding this mechanism will be helpful to find out the detail of reprogramming, which may provide a new therapy in medical science by generating patient-specific pluripotent stem cells.
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Affiliation(s)
- Ling He
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
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46
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Genetics and epigenetics of cutaneous malignant melanoma: a concert out of tune. Biochim Biophys Acta Rev Cancer 2012; 1826:89-102. [PMID: 22503822 DOI: 10.1016/j.bbcan.2012.03.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 03/09/2012] [Accepted: 03/10/2012] [Indexed: 01/05/2023]
Abstract
Cutaneous malignant melanoma (CMM) is the most life-threatening neoplasm of the skin and is considered a major health problem as both incidence and mortality rates continue to rise. Once CMM has metastasized it becomes therapy-resistant and is an inevitably deadly disease. Understanding the molecular mechanisms that are involved in the initiation and progression of CMM is crucial for overcoming the commonly observed drug resistance as well as developing novel targeted treatment strategies. This molecular knowledge may further lead to the identification of clinically relevant biomarkers for early CMM detection, risk stratification, or prediction of response to therapy, altogether improving the clinical management of this disease. In this review we summarize the currently identified genetic and epigenetic alterations in CMM development. Although the genetic components underlying CMM are clearly emerging, a complete picture of the epigenetic alterations on DNA (DNA methylation), RNA (non-coding RNAs), and protein level (histone modifications, Polycomb group proteins, and chromatin remodeling) and the combinatorial interactions between these events is lacking. More detailed knowledge, however, is accumulating for genetic and epigenetic interactions in the aberrant regulation of the INK4b-ARF-INK4a and microphthalmia-associated transcription factor (MITF) loci. Importantly, we point out that it is this interplay of genetics and epigenetics that effectively leads to distorted gene expression patterns in CMM.
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47
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Son YO, Lee SA, Kim SS, Jang YS, Chun JC, Lee JC. Acteoside inhibits melanogenesis in B16F10 cells through ERK activation and tyrosinase down-regulation. J Pharm Pharmacol 2011; 63:1309-19. [DOI: 10.1111/j.2042-7158.2011.01335.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Abstract
Objectives
Acteoside is a phenylpropanoid glycoside extracted from the leaves of Rehmannia glutinosa that displays various biological activities. In this study, we tested the effects of acteoside on tyrosinase activity and melanin biosynthesis in B16F10 melanoma cells. We also explored molecular mechanisms for the inhibition of melanogenesis observed, focusing on the signalling pathway of extracellular signal-regulated kinase (ERK).
Methods
The effects of acteoside were determined using several cell-free assay systems and B16F10 melanoma cells for melanin content and tyrosinase activity. To investigate effects on melanogenic regulatory factors we performed reverse transcription polymerase chain reaction, cAMP assay and Western blot analyses.
Key findings
Acteoside showed an inhibitory effect on tyrosinase activity and melanin synthesis in both cell-free assay systems and cultured B16F10 melanoma cells. Acteoside decreased levels of tyrosinase, tyrosinase-related protein-1 (TRP-1) and microphthalmia-associated transcription factor (MITF) proteins, whereas it increased ERK phosphorylation. A specific ERK inhibitor, PD98059, abolished the acteoside-induced down-regulation of MITF, tyrosinase and TRP-1 proteins. The ERK inhibitor increased tyrosinase activity and melanin production and reversed the acteoside-induced decrease in tyrosinase activity and melanin content. In addition, acteoside suppressed melanogenesis induced by α-melanocyte-stimulating hormone and showed UV-absorbing effects.
Conclusions
Acteoside decreased tyrosinase activity and melanin biosynthesis in B16F10 cells by activating ERK signalling, which down-regulated MITF, tyrosinase and TRP-1 production.
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Affiliation(s)
- Young-Ok Son
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY, USA
| | - Seung-Ah Lee
- Research Center of Bioactive Materials, Chonbuk National University, Jeonju, South Korea
- Department of Nursing, Chonnam Techno College, Chonnam, South Korea
| | - So-Soon Kim
- Research Center of Bioactive Materials, Chonbuk National University, Jeonju, South Korea
| | - Yong-Suk Jang
- Research Center of Bioactive Materials, Chonbuk National University, Jeonju, South Korea
- Division of Biological Sciences, Chonbuk National University, Jeonju, South Korea
| | - Jae-Chul Chun
- Research Center of Bioactive Materials, Chonbuk National University, Jeonju, South Korea
| | - Jeong-Chae Lee
- Research Center of Bioactive Materials, Chonbuk National University, Jeonju, South Korea
- Institute of Oral Biosciences and BK21 Program, Chonbuk National University, Jeonju, South Korea
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Taylor KL, Lister JA, Zeng Z, Ishizaki H, Anderson C, Kelsh RN, Jackson IJ, Patton EE. Differentiated melanocyte cell division occurs in vivo and is promoted by mutations in Mitf. Development 2011; 138:3579-89. [PMID: 21771814 DOI: 10.1242/dev.064014] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Coordination of cell proliferation and differentiation is crucial for tissue formation, repair and regeneration. Some tissues, such as skin and blood, depend on differentiation of a pluripotent stem cell population, whereas others depend on the division of differentiated cells. In development and in the hair follicle, pigmented melanocytes are derived from undifferentiated precursor cells or stem cells. However, differentiated melanocytes may also have proliferative capacity in animals, and the potential for differentiated melanocyte cell division in development and regeneration remains largely unexplored. Here, we use time-lapse imaging of the developing zebrafish to show that while most melanocytes arise from undifferentiated precursor cells, an unexpected subpopulation of differentiated melanocytes arises by cell division. Depletion of the overall melanocyte population triggers a regeneration phase in which differentiated melanocyte division is significantly enhanced, particularly in young differentiated melanocytes. Additionally, we find reduced levels of Mitf activity using an mitfa temperature-sensitive line results in a dramatic increase in differentiated melanocyte cell division. This supports models that in addition to promoting differentiation, Mitf also promotes withdrawal from the cell cycle. We suggest differentiated cell division is relevant to melanoma progression because the human melanoma mutation MITF(4T)(Δ)(2B) promotes increased and serial differentiated melanocyte division in zebrafish. These results reveal a novel pathway of differentiated melanocyte division in vivo, and that Mitf activity is essential for maintaining cell cycle arrest in differentiated melanocytes.
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Affiliation(s)
- Kerrie L Taylor
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Crewe Road South, Edinburgh EH4 2XR, UK
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Anvekar RA, Asciolla JJ, Missert DJ, Chipuk JE. Born to be alive: a role for the BCL-2 family in melanoma tumor cell survival, apoptosis, and treatment. Front Oncol 2011; 1. [PMID: 22268005 PMCID: PMC3260552 DOI: 10.3389/fonc.2011.00034] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The global incidence of melanoma has dramatically increased during the recent decades, yet the advancement of primary and adjuvant therapies has not kept a similar pace. The development of melanoma is often centered on cellular signaling that hyper-activates survival pathways, while inducing a concomitant blockade to cell death. Aberrations in cell death signaling not only promote tumor survival and enhanced metastatic potential, but also create resistance to anti-tumor strategies. Chemotherapeutic agents target melanoma tumor cells by inducing a form of cell death called apoptosis, which is governed by the BCL-2 family of proteins. The BCL-2 family is comprised of anti-apoptotic proteins (e.g., BCL-2, BCL-xL, and MCL-1) and pro-apoptotic proteins (e.g., BAK, BAX, and BIM), and their coordinated regulation and function are essential for optimal responses to chemotherapeutics. Here we will discuss what is currently known about the mechanisms of BCL-2 family function with a focus on the signaling pathways that maintain melanoma tumor cell survival. Importantly, we will critically evaluate the literature regarding how chemotherapeutic strategies directly impact on BCL-2 family function and offer several suggestions for future regimens to target melanoma and enhance patient survival.
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Affiliation(s)
- Rina A Anvekar
- Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY, USA
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Saladi SV, Keenen B, Marathe HG, Qi H, Chin KV, de la Serna IL. Modulation of extracellular matrix/adhesion molecule expression by BRG1 is associated with increased melanoma invasiveness. Mol Cancer 2010; 9:280. [PMID: 20969766 PMCID: PMC3098014 DOI: 10.1186/1476-4598-9-280] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 10/22/2010] [Indexed: 04/22/2023] Open
Abstract
BACKGROUND Metastatic melanoma is an aggressive malignancy that is resistant to therapy and has a poor prognosis. The progression of primary melanoma to metastatic disease is a multi-step process that requires dynamic regulation of gene expression through currently uncharacterized epigenetic mechanisms. Epigenetic regulation of gene expression often involves changes in chromatin structure that are catalyzed by chromatin remodeling enzymes. Understanding the mechanisms involved in the regulation of gene expression during metastasis is important for developing an effective strategy to treat metastatic melanoma. SWI/SNF enzymes are multisubunit complexes that contain either BRG1 or BRM as the catalytic subunit. We previously demonstrated that heterogeneous SWI/SNF complexes containing either BRG1 or BRM are epigenetic modulators that regulate important aspects of the melanoma phenotype and are required for melanoma tumorigenicity in vitro. RESULTS To characterize BRG1 expression during melanoma progression, we assayed expression of BRG1 in patient derived normal skin and in melanoma specimen. BRG1 mRNA levels were significantly higher in stage IV melanomas compared to stage III tumors and to normal skin. To determine the role of BRG1 in regulating the expression of genes involved in melanoma metastasis, we expressed BRG1 in a melanoma cell line that lacks BRG1 expression and examined changes in extracellular matrix and adhesion molecule expression. We found that BRG1 modulated the expression of a subset of extracellular matrix remodeling enzymes and adhesion proteins. Furthermore, BRG1 altered melanoma adhesion to different extracellular matrix components. Expression of BRG1 in melanoma cells that lack BRG1 increased invasive ability while down-regulation of BRG1 inhibited invasive ability in vitro. Activation of metalloproteinase (MMP) 2 expression greatly contributed to the BRG1 induced increase in melanoma invasiveness. We found that BRG1 is recruited to the MMP2 promoter and directly activates expression of this metastasis associated gene. CONCLUSIONS We provide evidence that BRG1 expression increases during melanoma progression. Our study has identified BRG1 target genes that play an important role in melanoma metastasis and we show that BRG1 promotes melanoma invasive ability in vitro. These results suggest that increased BRG1 levels promote the epigenetic changes in gene expression required for melanoma metastasis to proceed.
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Affiliation(s)
- Srinivas Vinod Saladi
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Bridget Keenen
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Himangi G Marathe
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Huiling Qi
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Khew-Voon Chin
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
- Department of Medicine, The University of Toledo College of Medicine, 3000 Arlington Avenue, Toledo, OH 43614, USA
- Center for Diabetes and Endocrine Research, The University of Toledo College of Medicine, 3000 Arlington Avenue, Toledo, OH 43614, USA
| | - Ivana L de la Serna
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
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