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Ostacolo K, López García de Lomana A, Larat C, Hjaltalin V, Holm KY, Hlynsdóttir SS, Soucheray M, Sooman L, Rolfsson O, Krogan NJ, Steingrimsson E, Swaney DL, Ogmundsdottir MH. ATG7(2) Interacts With Metabolic Proteins and Regulates Central Energy Metabolism. Traffic 2024; 25:e12933. [PMID: 38600522 DOI: 10.1111/tra.12933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 03/01/2024] [Accepted: 03/10/2024] [Indexed: 04/12/2024]
Abstract
Macroautophagy/autophagy is an essential catabolic process that targets a wide variety of cellular components including proteins, organelles, and pathogens. ATG7, a protein involved in the autophagy process, plays a crucial role in maintaining cellular homeostasis and can contribute to the development of diseases such as cancer. ATG7 initiates autophagy by facilitating the lipidation of the ATG8 proteins in the growing autophagosome membrane. The noncanonical isoform ATG7(2) is unable to perform ATG8 lipidation; however, its cellular regulation and function are unknown. Here, we uncovered a distinct regulation and function of ATG7(2) in contrast with ATG7(1), the canonical isoform. First, affinity-purification mass spectrometry analysis revealed that ATG7(2) establishes direct protein-protein interactions (PPIs) with metabolic proteins, whereas ATG7(1) primarily interacts with autophagy machinery proteins. Furthermore, we identified that ATG7(2) mediates a decrease in metabolic activity, highlighting a novel splice-dependent function of this important autophagy protein. Then, we found a divergent expression pattern of ATG7(1) and ATG7(2) across human tissues. Conclusively, our work uncovers the divergent patterns of expression, protein interactions, and function of ATG7(2) in contrast to ATG7(1). These findings suggest a molecular switch between main catabolic processes through isoform-dependent expression of a key autophagy gene.
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Affiliation(s)
- Kevin Ostacolo
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Adrián López García de Lomana
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Clémence Larat
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Valgerdur Hjaltalin
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Kristrun Yr Holm
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Sigríður S Hlynsdóttir
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Margaret Soucheray
- Gladstone Institutes, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, California, USA
| | - Linda Sooman
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Ottar Rolfsson
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Nevan J Krogan
- Gladstone Institutes, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, California, USA
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Danielle L Swaney
- Gladstone Institutes, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, California, USA
| | - Margret H Ogmundsdottir
- Department of Anatomy, Biomedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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Amarnani A, Lopez-Ocasio M, Dilshat R, Anumukonda K, Davila J, Malakhov N, Huan C, Magnusdottir E, Steingrimsson E, Roman CA. Mitf regulates gene expression networks implicated in B cell homeostasis, germinal center responses, and tolerance. Front Immunol 2024; 15:1339325. [PMID: 38444862 PMCID: PMC10912573 DOI: 10.3389/fimmu.2024.1339325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/08/2024] [Indexed: 03/07/2024] Open
Abstract
Introduction The microphthalmia transcription factor Mitf has been shown to regulate B cell activation and tolerance. However, the underlying B cell-specific mechanisms responsible, and those that distinguish Mitf from closely related Mitf/TFE (MiT) transcription factors Tfe3, Tfeb, and Tfec, remain obscure. Methods Two complementary mouse models of Mitf and MiT deficiency were used: the Mitfmi-vga9/mi-vga9 systemic loss-of-function mutation, and B-cell specific MiT family inactivation via transgenic expression of a trans-dominant negative (TDN) protein (TDN-B). These models were employed to identify MiT family candidate target genes and pathways. Results Both models displayed spontaneous splenomegaly coincident with elevated plasma cell numbers, autoantibody titers, and proteinuria. These abnormalities appeared dependent on T helper cells, but independent of other non-B cell intrinsic effects of systemic Mitf inactivation. MiT inactivation in B cells augmented aspects of lupus-like autoimmune disease on the C57BL/6-Faslpr/lpr background. In both models, RNAseq of ex vivo resting B cells showed transcriptional upregulation of genes that control cell cycle, germinal center responses, and plasma cell differentiation. Among the genes strongly upregulated in both models were Socs6, Isp53 (Baiap1), S1pR2, and IgG2b/c. Mitf null B cells, but not TDN-B cells, showed evidence of type I interferon dysregulation. Discussion These studies clarify Mitf's role as 1) a key regulator of a B cell intrinsic germinal center program that influences self-tolerance through novel target genes, and 2) a regulator of systemic inflammatory processes that can impact the B cell microenvironment. This distinction of Mitf's function from that of related MiT transcription factors advances our understanding of B cell regulation and autoimmunity.
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Affiliation(s)
- Abhimanyu Amarnani
- Program in Molecular and Cellular Biology, School of Graduate Studies, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
- School of Medicine, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
- Department of Medicine, Division of Rheumatology, New York University Langone Health, New York, NY, United States
| | - Maria Lopez-Ocasio
- Program in Molecular and Cellular Biology, School of Graduate Studies, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Ramile Dilshat
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Biomedical Center, University of Iceland, Reykjavik, Iceland
| | - Kamala Anumukonda
- Program in Molecular and Cellular Biology, School of Graduate Studies, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
- Anuko Tech Inc., Hillsborough, NJ, United States
| | - Jonathan Davila
- School of Medicine, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
- Department of Urology, Northwell Health, Staten Island, NY, United States
| | - Nikita Malakhov
- School of Medicine, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
- Department of Hematology and Oncology, NewYork-Presbyterian-Weill Cornell Medical Center, New York, NY, United States
| | - Chongmin Huan
- Program in Molecular and Cellular Biology, School of Graduate Studies, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
| | - Erna Magnusdottir
- Department of Anatomy, Faculty of Medicine, Biomedical Center, University of Iceland, Reykjavik, Iceland
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Biomedical Center, University of Iceland, Reykjavik, Iceland
| | - Christopher A. Roman
- Program in Molecular and Cellular Biology, School of Graduate Studies, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
- School of Medicine, State University of New York (SUNY) Downstate Health Sciences University, Brooklyn, NY, United States
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3
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Greer SU, Chen J, Ogmundsdottir MH, Ayala C, Lau BT, Delacruz RGC, Sandoval IT, Kristjansdottir S, Jones DA, Haslem DS, Romero R, Fulde G, Bell JM, Jonasson JG, Steingrimsson E, Ji HP, Nadauld LD. Germline variants of ATG7 in familial cholangiocarcinoma alter autophagy and p62. Sci Rep 2022; 12:10333. [PMID: 35725745 PMCID: PMC9209431 DOI: 10.1038/s41598-022-13569-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 05/25/2022] [Indexed: 12/20/2022] Open
Abstract
Autophagy is a housekeeping mechanism tasked with eliminating misfolded proteins and damaged organelles to maintain cellular homeostasis. Autophagy deficiency results in increased oxidative stress, DNA damage and chronic cellular injury. Among the core genes in the autophagy machinery, ATG7 is required for autophagy initiation and autophagosome formation. Based on the analysis of an extended pedigree of familial cholangiocarcinoma, we determined that all affected family members had a novel germline mutation (c.2000C>T p.Arg659* (p.R659*)) in ATG7. Somatic deletions of ATG7 were identified in the tumors of affected individuals. We applied linked-read sequencing to one tumor sample and demonstrated that the ATG7 somatic deletion and germline mutation were located on distinct alleles, resulting in two hits to ATG7. From a parallel population genetic study, we identified a germline polymorphism of ATG7 (c.1591C>G p.Asp522Glu (p.D522E)) associated with increased risk of cholangiocarcinoma. To characterize the impact of these germline ATG7 variants on autophagy activity, we developed an ATG7-null cell line derived from the human bile duct. The mutant p.R659* ATG7 protein lacked the ability to lipidate its LC3 substrate, leading to complete loss of autophagy and increased p62 levels. Our findings indicate that germline ATG7 variants have the potential to impact autophagy function with implications for cholangiocarcinoma development.
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Affiliation(s)
- Stephanie U Greer
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Jiamin Chen
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Margret H Ogmundsdottir
- Department of Anatomy, Faculty of Medicine, BioMedical Center, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - Carlos Ayala
- Division of General Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Billy T Lau
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Richard Glenn C Delacruz
- Intermountain Precision Genomics Program, Intermountain Healthcare, Saint George, UT, 84790, USA
- Oklahoma Medical Research Foundation, Oklahoma University, Oklahoma City, OK, 73104, USA
| | - Imelda T Sandoval
- Intermountain Precision Genomics Program, Intermountain Healthcare, Saint George, UT, 84790, USA
- Oklahoma Medical Research Foundation, Oklahoma University, Oklahoma City, OK, 73104, USA
| | | | - David A Jones
- Intermountain Precision Genomics Program, Intermountain Healthcare, Saint George, UT, 84790, USA
- Oklahoma Medical Research Foundation, Oklahoma University, Oklahoma City, OK, 73104, USA
| | - Derrick S Haslem
- Intermountain Precision Genomics Program, Intermountain Healthcare, Saint George, UT, 84790, USA
| | - Robin Romero
- Intermountain Precision Genomics Program, Intermountain Healthcare, Saint George, UT, 84790, USA
| | - Gail Fulde
- Intermountain Precision Genomics Program, Intermountain Healthcare, Saint George, UT, 84790, USA
| | - John M Bell
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, 94304, USA
| | - Jon G Jonasson
- Department of Pathology, Landspítali-University Hospital, 101, Reykjavik, Iceland
- Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, BioMedical Center, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - Hanlee P Ji
- Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, 94304, USA.
| | - Lincoln D Nadauld
- Intermountain Precision Genomics Program, Intermountain Healthcare, Saint George, UT, 84790, USA.
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4
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Hamm M, Sohier P, Petit V, Raymond JH, Delmas V, Le Coz M, Gesbert F, Kenny C, Aktary Z, Pouteaux M, Rambow F, Sarasin A, Charoenchon N, Bellacosa A, Sanchez-Del-Campo L, Mosteo L, Lauss M, Meijer D, Steingrimsson E, Jönsson GB, Cornell RA, Davidson I, Goding CR, Larue L. BRN2 is a non-canonical melanoma tumor-suppressor. Nat Commun 2021; 12:3707. [PMID: 34140478 PMCID: PMC8211827 DOI: 10.1038/s41467-021-23973-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 05/27/2021] [Indexed: 12/13/2022] Open
Abstract
While the major drivers of melanoma initiation, including activation of NRAS/BRAF and loss of PTEN or CDKN2A, have been identified, the role of key transcription factors that impose altered transcriptional states in response to deregulated signaling is not well understood. The POU domain transcription factor BRN2 is a key regulator of melanoma invasion, yet its role in melanoma initiation remains unknown. Here, in a BrafV600E PtenF/+ context, we show that BRN2 haplo-insufficiency promotes melanoma initiation and metastasis. However, metastatic colonization is less efficient in the absence of Brn2. Mechanistically, BRN2 directly induces PTEN expression and in consequence represses PI3K signaling. Moreover, MITF, a BRN2 target, represses PTEN transcription. Collectively, our results suggest that on a PTEN heterozygous background somatic deletion of one BRN2 allele and temporal regulation of the other allele elicits melanoma initiation and progression.
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Affiliation(s)
- Michael Hamm
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Pierre Sohier
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Valérie Petit
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Jérémy H Raymond
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Véronique Delmas
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Madeleine Le Coz
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Franck Gesbert
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Colin Kenny
- Department of Anatomy and Cell biology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Zackie Aktary
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Marie Pouteaux
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Florian Rambow
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
| | - Alain Sarasin
- Laboratory of Genetic Instability and Oncogenesis, UMR8200 CNRS, Gustave Roussy, Université Paris-Sud, Villejuif, France
| | - Nisamanee Charoenchon
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Equipes Labellisées Ligue Contre le Cancer, Paris, France
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Alfonso Bellacosa
- Cancer Epigenetics Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Luis Sanchez-Del-Campo
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, UK
| | - Laura Mosteo
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, UK
| | - Martin Lauss
- Department of Oncology, Clinical Sciences Lund, Lund University and Skåne University Hospital, Lund, Sweden
| | - Dies Meijer
- Centre of Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, and Department of Anatomy, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Göran B Jönsson
- Department of Oncology, Clinical Sciences Lund, Lund University and Skåne University Hospital, Lund, Sweden
| | - Robert A Cornell
- Department of Anatomy and Cell biology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Irwin Davidson
- Department of Anatomy and Cell biology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, 1 Rue Laurent Fries, 67404, Illkirch, Cedex, France
| | - Colin R Goding
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, Oxford, UK.
| | - Lionel Larue
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Normal and Pathological Development of Melanocytes, Orsay, France.
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France.
- Equipes Labellisées Ligue Contre le Cancer, Paris, France.
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5
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Dilshat R, Fock V, Kenny C, Gerritsen I, Lasseur RMJ, Travnickova J, Eichhoff OM, Cerny P, Möller K, Sigurbjörnsdóttir S, Kirty K, Einarsdottir BÓ, Cheng PF, Levesque M, Cornell RA, Patton EE, Larue L, de Tayrac M, Magnúsdóttir E, Ögmundsdóttir MH, Steingrimsson E. MITF reprograms the extracellular matrix and focal adhesion in melanoma. eLife 2021; 10:63093. [PMID: 33438577 PMCID: PMC7857731 DOI: 10.7554/elife.63093] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/11/2021] [Indexed: 12/20/2022] Open
Abstract
The microphthalmia-associated transcription factor (MITF) is a critical regulator of melanocyte development and differentiation. It also plays an important role in melanoma where it has been described as a molecular rheostat that, depending on activity levels, allows reversible switching between different cellular states. Here, we show that MITF directly represses the expression of genes associated with the extracellular matrix (ECM) and focal adhesion pathways in human melanoma cells as well as of regulators of epithelial-to-mesenchymal transition (EMT) such as CDH2, thus affecting cell morphology and cell-matrix interactions. Importantly, we show that these effects of MITF are reversible, as expected from the rheostat model. The number of focal adhesion points increased upon MITF knockdown, a feature observed in drug-resistant melanomas. Cells lacking MITF are similar to the cells of minimal residual disease observed in both human and zebrafish melanomas. Our results suggest that MITF plays a critical role as a repressor of gene expression and is actively involved in shaping the microenvironment of melanoma cells in a cell-autonomous manner.
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Affiliation(s)
- Ramile Dilshat
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Valerie Fock
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Colin Kenny
- Department of Anatomy and Cell biology, Carver College of Medicine, University of Iowa, Iowa City, United States
| | - Ilse Gerritsen
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Romain Maurice Jacques Lasseur
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Jana Travnickova
- MRC Institute of Genetics and Molecular Medicine, MRC Human Genetics Unit, University of Edinburgh, Edinburgh, United Kingdom
| | - Ossia M Eichhoff
- Department of Dermatology, University Hospital Zurich, Zurich, Switzerland
| | - Philipp Cerny
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Katrin Möller
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Sara Sigurbjörnsdóttir
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Kritika Kirty
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Berglind Ósk Einarsdottir
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Phil F Cheng
- Department of Dermatology, University Hospital Zurich, Zurich, Switzerland
| | - Mitchell Levesque
- Department of Dermatology, University Hospital Zurich, Zurich, Switzerland
| | - Robert A Cornell
- Department of Anatomy and Cell biology, Carver College of Medicine, University of Iowa, Iowa City, United States
| | - E Elizabeth Patton
- MRC Institute of Genetics and Molecular Medicine, MRC Human Genetics Unit, University of Edinburgh, Edinburgh, United Kingdom
| | - Lionel Larue
- Institut Curie, CNRS UMR3347, INSERM U1021, Centre Universitaire, Orsay, France
| | - Marie de Tayrac
- Service de Génétique Moléculaire et Génomique, CHU, Rennes, France.,Univ Rennes1, CNRS, IGDR (Institut de Génétique et Développement de Rennes), Rennes, France
| | - Erna Magnúsdóttir
- Department of Anatomy, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Margrét Helga Ögmundsdóttir
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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6
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Brownstein Z, Gulsuner S, Walsh T, Martins FTA, Taiber S, Isakov O, Lee MK, Bordeynik-Cohen M, Birkan M, Chang W, Casadei S, Danial-Farran N, Abu-Rayyan A, Carlson R, Kamal L, Arnthórsson AÖ, Sokolov M, Gilony D, Lipschitz N, Frydman M, Davidov B, Macarov M, Sagi M, Vinkler C, Poran H, Sharony R, Samra N, Zvi N, Baris-Feldman H, Singer A, Handzel O, Hertzano R, Ali-Naffaa D, Ruhrman-Shahar N, Madgar O, Sofrin-Drucker E, Peleg A, Khayat M, Shohat M, Basel-Salmon L, Pras E, Lev D, Wolf M, Steingrimsson E, Shomron N, Kelley MW, Kanaan MN, Allon-Shalev S, King MC, Avraham KB. Spectrum of genes for inherited hearing loss in the Israeli Jewish population, including the novel human deafness gene ATOH1. Clin Genet 2020; 98:353-364. [PMID: 33111345 DOI: 10.1111/cge.13817] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 12/26/2022]
Abstract
Mutations in more than 150 genes are responsible for inherited hearing loss, with thousands of different, severe causal alleles that vary among populations. The Israeli Jewish population includes communities of diverse geographic origins, revealing a wide range of deafness-associated variants and enabling clinical characterization of the associated phenotypes. Our goal was to identify the genetic causes of inherited hearing loss in this population, and to determine relationships among genotype, phenotype, and ethnicity. Genomic DNA samples from informative relatives of 88 multiplex families, all of self-identified Jewish ancestry, with either non-syndromic or syndromic hearing loss, were sequenced for known and candidate deafness genes using the HEar-Seq gene panel. The genetic causes of hearing loss were identified for 60% of the families. One gene was encountered for the first time in human hearing loss: ATOH1 (Atonal), a basic helix-loop-helix transcription factor responsible for autosomal dominant progressive hearing loss in a five-generation family. Our results show that genomic sequencing with a gene panel dedicated to hearing loss is effective for genetic diagnoses in a diverse population. Comprehensive sequencing enables well-informed genetic counseling and clinical management by medical geneticists, otolaryngologists, audiologists, and speech therapists and can be integrated into newborn screening for deafness.
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Affiliation(s)
- Zippora Brownstein
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Suleyman Gulsuner
- Departments of Genome Sciences and Medicine, University of Washington, Seattle, Washington, USA
| | - Tom Walsh
- Departments of Genome Sciences and Medicine, University of Washington, Seattle, Washington, USA
| | - Fábio T A Martins
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Taiber
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ofer Isakov
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ming K Lee
- Departments of Genome Sciences and Medicine, University of Washington, Seattle, Washington, USA
| | - Mor Bordeynik-Cohen
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Maria Birkan
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Raphael Recanati Genetic Institute, Rabin Medical Center-Beilinson Hospital, Tel Aviv University Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Weise Chang
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Silvia Casadei
- Departments of Genome Sciences and Medicine, University of Washington, Seattle, Washington, USA
| | - Nada Danial-Farran
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Genetics Institute, Ha'Emek Medical Center, Afula, Israel.,Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Amal Abu-Rayyan
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Department of Biological Sciences, Bethlehem University, Bethlehem, Palestine
| | - Ryan Carlson
- Departments of Genome Sciences and Medicine, University of Washington, Seattle, Washington, USA
| | - Lara Kamal
- Department of Biological Sciences, Bethlehem University, Bethlehem, Palestine
| | - Asgeir Ö Arnthórsson
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Meirav Sokolov
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Department of Otolaryngology-Head and Neck Surgery, Schneider Children's Medical Center, Petach Tikva, Israel
| | - Dror Gilony
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Department of Otolaryngology-Head and Neck Surgery, Schneider Children's Medical Center, Petach Tikva, Israel
| | - Noga Lipschitz
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Department of Otolaryngology-Head and Neck Surgery, Sheba Medical Center, Tel Hashomer, Israel
| | - Moshe Frydman
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Bella Davidov
- Raphael Recanati Genetic Institute, Rabin Medical Center-Beilinson Hospital, Tel Aviv University Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Michal Macarov
- Department of Human Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Michal Sagi
- Department of Human Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Chana Vinkler
- Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel
| | - Hana Poran
- Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Reuven Sharony
- Genetics Institute, Meir Medical Center, Kfar Saba and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Na'ama Zvi
- Department of Human Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Hagit Baris-Feldman
- Genetics Institute, Tel-Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Amihood Singer
- Community Genetics Department, Public Health Services, Ministry of Health, Ramat Gan, Israel
| | - Ophir Handzel
- Department of Otolaryngology Head and Neck Surgery and Maxillofacial Surgery, Tel-Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ronna Hertzano
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Doaa Ali-Naffaa
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Human Genetics Institute, Lady Davis Carmel Medical Center, Haifa, Israel
| | - Noa Ruhrman-Shahar
- Raphael Recanati Genetic Institute, Rabin Medical Center-Beilinson Hospital, Tel Aviv University Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Ory Madgar
- Department of Otolaryngology-Head and Neck Surgery, Sheba Medical Center, Tel Hashomer, Israel
| | - Efrat Sofrin-Drucker
- Raphael Recanati Genetic Institute, Rabin Medical Center-Beilinson Hospital, Tel Aviv University Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Amir Peleg
- Human Genetics Institute, Lady Davis Carmel Medical Center, Haifa, Israel
| | - Morad Khayat
- Genetics Institute, Ha'Emek Medical Center, Afula, Israel
| | - Mordechai Shohat
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Israel.,Institute of Medical Genetics, Maccabi HMO, Rehovot, Israel
| | - Lina Basel-Salmon
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Raphael Recanati Genetic Institute, Rabin Medical Center-Beilinson Hospital, Tel Aviv University Felsenstein Medical Research Center, Petach Tikva, Israel
| | - Elon Pras
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Dorit Lev
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel
| | - Michael Wolf
- Department of Otolaryngology-Head and Neck Surgery, Sheba Medical Center, Tel Hashomer, Israel
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Noam Shomron
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Matthew W Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Moien N Kanaan
- Department of Biological Sciences, Bethlehem University, Bethlehem, Palestine
| | - Stavit Allon-Shalev
- Genetics Institute, Ha'Emek Medical Center, Afula, Israel.,Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Mary-Claire King
- Departments of Genome Sciences and Medicine, University of Washington, Seattle, Washington, USA
| | - Karen B Avraham
- Department of Human Molecular Genetics & Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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7
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Abstract
Cutaneous melanoma arises from melanocytes following genetic, epigenetic and allogenetic (i.e. other than epi/genetic) modifications. An estimated 10% of cutaneous melanoma cases are due to inherited variants or de novo mutations in approximately 20 genes, found using linkage, next-generation sequencing and association studies. Based on these studies, 3 classes of predisposing melanoma genes have been defined based on the frequency of the variants in the general population and lifetime risk of developing a melanoma: (i) ultra-rare variants with a high risk, (ii) rare with a moderate risk, and (iii) frequent variants with a low risk. Most of the proteins encoded by these genes have been shown to be involved in melanoma initiation, including proliferation and senescence bypass. This paper reviews the role(s) of these genes in the transformation of melanocytes into melanoma. It also describes their function in the establishment and renewal of melanocytes and the biology of pigment cells, if known.
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Affiliation(s)
- Julie U Bertrand
- Curie Institute, PSL Research University, INSERM U1021, Normal and Pathological Development of Melanocytes, Orsay, France
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8
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Ogmundsdottir MH, Fock V, Sooman L, Pogenberg V, Dilshat R, Bindesbøll C, Ogmundsdottir HM, Simonsen A, Wilmanns M, Steingrimsson E. A short isoform of ATG7 fails to lipidate LC3/GABARAP. Sci Rep 2018; 8:14391. [PMID: 30258106 PMCID: PMC6158294 DOI: 10.1038/s41598-018-32694-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/10/2018] [Indexed: 12/13/2022] Open
Abstract
Autophagy is a degradation pathway important for cellular homeostasis. The E1-like enzyme ATG7 is a key component of the autophagy machinery, with the main function of mediating the lipidation of LC3/GABARAP during autophagosome formation. By analysing mRNA-sequencing data we found that in addition to the full-length ATG7 isoform, various tissues express a shorter isoform lacking an exon of 27 amino acids in the C-terminal part of the protein, termed ATG7(2). We further show that ATG7(2) does not bind LC3B and fails to mediate the lipidation of members of the LC3/GABARAP family. We have thus identified an isoform of ATG7 that is unable to carry out the best characterized function of the protein during the autophagic response. This short isoform will have to be taken into consideration when further studying the role of ATG7.
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Affiliation(s)
- M H Ogmundsdottir
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland.
| | - V Fock
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - L Sooman
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - V Pogenberg
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607, Hamburg, Germany
| | - R Dilshat
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - C Bindesbøll
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Sognsvannsveien 9, N-0317, Oslo, Norway
| | - H M Ogmundsdottir
- Cancer Research Laboratory, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - A Simonsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Sognsvannsveien 9, N-0317, Oslo, Norway
| | - M Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607, Hamburg, Germany
| | - E Steingrimsson
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland.
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9
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Fock V, Gudmundsson SR, Gunnlaugsson HO, Stefansson JA, Ionasz V, Schepsky A, Viarigi J, Reynisson IE, Pogenberg V, Wilmanns M, Ogmundsdottir MH, Steingrimsson E. Subcellular localization and stability of MITF are modulated by the bHLH-Zip domain. Pigment Cell Melanoma Res 2018; 32:41-54. [PMID: 29938923 DOI: 10.1111/pcmr.12721] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/01/2018] [Accepted: 06/19/2018] [Indexed: 12/15/2022]
Abstract
Microphthalmia-associated transcription factor (MITF) is a member of the basic helix-loop-helix leucine zipper (bHLH-Zip) family and functions as the master regulator of the melanocytic lineage. MITF-M is the predominant isoform expressed in melanocytes and melanoma cells, and, unlike other MITF isoforms, it is constitutively nuclear. Mutational analysis revealed three karyophilic signals in the bHLH-Zip domain of MITF-M, spanning residues 197-206, 214-217, and 255-265. Structural characterization of the MITF protein showed that basic residues within these signals are exposed for interactions in the absence of DNA. Moreover, our data indicate that neither DNA binding nor dimerization of MITF-M are required for its nuclear localization. Finally, dimerization-deficient MITF-M mutants exhibited a significantly reduced stability in melanoma cells when compared to the wild-type protein. Taken together, we have shown that, in addition to its well-established role in DNA binding and dimer formation, the bHLH-Zip domain of MITF modulates the transcription factor's subcellular localization and stability.
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Affiliation(s)
- Valerie Fock
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Sigurdur Runar Gudmundsson
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Hilmar Orn Gunnlaugsson
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Jon August Stefansson
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Vivien Ionasz
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Alexander Schepsky
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Jade Viarigi
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Indridi Einar Reynisson
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | | | | | - Margret Helga Ogmundsdottir
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Eirikur Steingrimsson
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, BioMedical Center, University of Iceland, Reykjavik, Iceland
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10
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Pallares LF, Ledevin R, Pantalacci S, Turner LM, Steingrimsson E, Renaud S. Genomic regions controlling shape variation in the first upper molar of the house mouse. eLife 2017; 6:29510. [PMID: 29091026 PMCID: PMC5679752 DOI: 10.7554/elife.29510] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 10/28/2017] [Indexed: 01/25/2023] Open
Abstract
Numerous loci of large effect have been shown to underlie phenotypic variation between species. However, loci with subtle effects are presumably more frequently involved in microevolutionary processes but have rarely been discovered. We explore the genetic basis of shape variation in the first upper molar of hybrid mice between Mus musculus musculus and M. m. domesticus. We performed the first genome-wide association study for molar shape and used 3D surface morphometrics to quantify subtle variation between individuals. We show that many loci of small effect underlie phenotypic variation, and identify five genomic regions associated with tooth shape; one region contained the gene microphthalmia-associated transcription factor Mitf that has previously been associated with tooth malformations. Using a panel of five mutant laboratory strains, we show the effect of the Mitf gene on tooth shape. This is the first report of a gene causing subtle but consistent variation in tooth shape resembling variation in nature.
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Affiliation(s)
- Luisa F Pallares
- Department of Evolutionary Genetics, Max-Planck Institute for Evolutionary Biology, Plön, Germany
| | - Ronan Ledevin
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, CNRS, University Lyon 1, Campus de la Doua, Villeurbanne, France
| | - Sophie Pantalacci
- ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratoire de Biologie et Modélisation de la Cellule, 15 parvis Descartes, F-69007, UnivLyon, Lyon, France
| | - Leslie M Turner
- Department of Evolutionary Genetics, Max-Planck Institute for Evolutionary Biology, Plön, Germany.,Department of Biology and Biochemistry, Milner Centre for Evolution, University of Bath, Bath, Unites States
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Sabrina Renaud
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, CNRS, University Lyon 1, Campus de la Doua, Villeurbanne, France
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11
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Garcia Llorca A, Gudmundsdóttir Aspelund S, Ogmundsdóttir M, Steingrimsson E, Eysteinsson T. Retinal function and morphology in Mitf mutant mice. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Garcia Llorca A, Ogmundsdóttir M, Steingrimsson E, Eysteinsson T. Autophagy is affected by Mitf in mouse primary RPE cells. Acta Ophthalmol 2016. [DOI: 10.1111/j.1755-3768.2016.0605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Moller K, Sigurbjornsdottir S, Dilixiati R, Brynjolfsdottir SH, Larue L, Thorsson V, Steingrimsson E, Ogmundsdottir MH. Abstract 224: The role of the microphthalmia associated transcription factor in autophagy regulation in melanoma. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Autophagy is considered a therapeutic target in various cancer types, including melanoma. The transcription factors TFEB and TFE3 have been shown to play a key role in autophagy regulation in various cell types by affecting gene expression required for this process. A close relative to these factors is the transcription factor MITF; often termed the master regulator of melanocyte development and function. MITF activity has also been shown to be important for various stages of melanoma formation and progression.
Analysis of The Cancer Genome Atlas expression data from melanoma tumors reveals that MITF expression correlates with lysosomal and autophagy gene expression in metastatic tumors. Furthermore, analysis of expression data from 23 melanoma cell lines shows that MITF expression correlates with lysosomal and autophagy gene expression, and the analysis of available MITF ChIP sequencing data shows that MITF binds the promoters of lysosomal and autophagy genes. This binding was experimentally verified by ChIP experiments in 501Mel melanoma cells. MITF over-expression and knock down experiments show effects of MITF on lysosomal and autophagy gene expression, as well as an effect on the autophagy activity.
Autophagy is high in melanoma and has been linked to tolerance against cancer treatment. We have found that MITF regulates autophagy genes and activity in melanoma cell lines. In light of both MITF and autophagy being considered a therapeutic target in melanoma, this relationship needs to be taken into consideration.
Citation Format: Katrin Moller, Sara Sigurbjornsdottir, Remina Dilixiati, Solveig H. Brynjolfsdottir, Lionel Larue, Vesteinn Thorsson, Eirikur Steingrimsson, Margret H. Ogmundsdottir. The role of the microphthalmia associated transcription factor in autophagy regulation in melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 224.
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14
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Gudjohnsen SAH, Atacho DAM, Gesbert F, Raposo G, Hurbain I, Larue L, Steingrimsson E, Petersen PH. Meningeal Melanocytes in the Mouse: Distribution and Dependence on Mitf. Front Neuroanat 2015; 9:149. [PMID: 26635543 PMCID: PMC4658736 DOI: 10.3389/fnana.2015.00149] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 11/06/2015] [Indexed: 12/27/2022] Open
Abstract
Summary: Melanocytes are pigment producing cells derived from the neural crest. They are primarily found in the skin and hair follicles, but can also be found in other tissues including the eye, ear and heart. Here, we describe the distribution of pigmented cells in C57BL/6J mouse meninges, the membranes that envelope the brain. These cells contain melanosomes of all four stages of development and they depend on Microphthalmia associated transcription factor (MITF), the master regulator of melanocyte development, suggesting that they are bona-fide melanocytes. The location of these pigmented cells is consistent with the location of meningeal melanomas in humans and animal models. Significance: Here, we document and define pigmented cells in the meninges of the mouse brain and confirm that they are melanocytes. This is important for understanding the role of this cell type and for understanding primary meningeal melanoma, a rare disease that likely arises from normal meningeal melanocytes.
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Affiliation(s)
- Stefán A H Gudjohnsen
- Faculty of Medicine, Department of Anatomy, Biomedical Center, University of Iceland Reykjavik, Iceland ; Faculty of Medicine, Department of Biochemistry and Molecular Biology, Biomedical Center, University of Iceland Reykjavik, Iceland
| | - Diahann A M Atacho
- Faculty of Medicine, Department of Anatomy, Biomedical Center, University of Iceland Reykjavik, Iceland ; Faculty of Medicine, Department of Biochemistry and Molecular Biology, Biomedical Center, University of Iceland Reykjavik, Iceland
| | - Franck Gesbert
- Institut Curie, PSL Research University, INSERM U1021, Normal and Pathological Development of Melanocytes Orsay, France ; Université Paris-Sud, Université Paris-Saclay, CNRS UMR 3347 Orsay, France ; Equipe Labellisée Ligue Contre le Cancer Orsay, France
| | - Graca Raposo
- Institut Curie, PSL Research University Paris, France ; CNRS UMR144, Structure and Membrane Compartments, and Cell and Tissue Imaging Facility (PICT-IBiSA) Paris, France
| | - Ilse Hurbain
- Institut Curie, PSL Research University Paris, France ; CNRS UMR144, Structure and Membrane Compartments, and Cell and Tissue Imaging Facility (PICT-IBiSA) Paris, France
| | - Lionel Larue
- Institut Curie, PSL Research University, INSERM U1021, Normal and Pathological Development of Melanocytes Orsay, France ; Université Paris-Sud, Université Paris-Saclay, CNRS UMR 3347 Orsay, France ; Equipe Labellisée Ligue Contre le Cancer Orsay, France
| | - Eirikur Steingrimsson
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, Biomedical Center, University of Iceland Reykjavik, Iceland
| | - Petur Henry Petersen
- Faculty of Medicine, Department of Anatomy, Biomedical Center, University of Iceland Reykjavik, Iceland
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15
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Zhang T, Zhou Q, Ogmundsdottir MH, Möller K, Siddaway R, Larue L, Hsing M, Kong SW, Goding CR, Palsson A, Steingrimsson E, Pignoni F. Mitf is a master regulator of the v-ATPase, forming a control module for cellular homeostasis with v-ATPase and TORC1. J Cell Sci 2015; 128:2938-50. [PMID: 26092939 DOI: 10.1242/jcs.173807] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 06/12/2015] [Indexed: 01/29/2023] Open
Abstract
The v-ATPase is a fundamental eukaryotic enzyme that is central to cellular homeostasis. Although its impact on key metabolic regulators such as TORC1 is well documented, our knowledge of mechanisms that regulate v-ATPase activity is limited. Here, we report that the Drosophila transcription factor Mitf is a master regulator of this holoenzyme. Mitf directly controls transcription of all 15 v-ATPase components through M-box cis-sites and this coordinated regulation affects holoenzyme activity in vivo. In addition, through the v-ATPase, Mitf promotes the activity of TORC1, which in turn negatively regulates Mitf. We provide evidence that Mitf, v-ATPase and TORC1 form a negative regulatory loop that maintains each of these important metabolic regulators in relative balance. Interestingly, direct regulation of v-ATPase genes by human MITF also occurs in cells of the melanocytic lineage, showing mechanistic conservation in the regulation of the v-ATPase by MITF family proteins in fly and mammals. Collectively, this evidence points to an ancient module comprising Mitf, v-ATPase and TORC1 that serves as a dynamic modulator of metabolism for cellular homeostasis.
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Affiliation(s)
- Tianyi Zhang
- Department of Ophthalmology, Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse, 13210 NY, USA
| | - Qingxiang Zhou
- Department of Ophthalmology, Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse, 13210 NY, USA
| | - Margret Helga Ogmundsdottir
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
| | - Katrin Möller
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
| | - Robert Siddaway
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, OX3 7DQ Oxford, UK
| | - Lionel Larue
- Institut Curie, INSERM U1021, CNRS UMR3347, Normal and Pathological Development of Melanocytes, 91405 Orsay, France
| | - Michael Hsing
- Informatics Program, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Sek Won Kong
- Informatics Program, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Colin Ronald Goding
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Headington, OX3 7DQ Oxford, UK
| | - Arnar Palsson
- Life and Environmental Sciences, School of Engineering and Natural Sciences, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, Reykjavik 101, Iceland
| | - Francesca Pignoni
- Department of Ophthalmology, Center for Vision Research and SUNY Eye Institute, Upstate Medical University, Syracuse, 13210 NY, USA Departments of Neuroscience and Physiology, Biochemistry and Molecular Biology, Upstate Medical University, Syracuse, 13210 NY, USA
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16
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Ogmundsdottir MH, Steingrimsson E. MITF regulation - more hints from Wnt. Pigment Cell Melanoma Res 2015; 28:372-3. [PMID: 25786516 DOI: 10.1111/pcmr.12366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Wagner RY, Luciani F, Cario-André M, Rubod A, Petit V, Benzekri L, Ezzedine K, Lepreux S, Steingrimsson E, Taieb A, Gauthier Y, Larue L, Delmas V. Altered E-Cadherin Levels and Distribution in Melanocytes Precede Clinical Manifestations of Vitiligo. J Invest Dermatol 2015; 135:1810-1819. [PMID: 25634357 DOI: 10.1038/jid.2015.25] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 12/26/2014] [Accepted: 01/14/2015] [Indexed: 12/26/2022]
Abstract
Vitiligo is the most common depigmenting disorder resulting from the loss of melanocytes from the basal epidermal layer. The pathogenesis of the disease is likely multifactorial and involves autoimmune causes, as well as oxidative and mechanical stress. It is important to identify early events in vitiligo to clarify pathogenesis, improve diagnosis, and inform therapy. Here, we show that E-cadherin (Ecad), which mediates the adhesion between melanocytes and keratinocytes in the epidermis, is absent from or discontinuously distributed across melanocyte membranes of vitiligo patients long before clinical lesions appear. This abnormality is associated with the detachment of the melanocytes from the basal to the suprabasal layers in the epidermis. Using human epidermal reconstructed skin and mouse models with normal or defective Ecad expression in melanocytes, we demonstrated that Ecad is required for melanocyte adhesiveness to the basal layer under oxidative and mechanical stress, establishing a link between silent/preclinical, cell-autonomous defects in vitiligo melanocytes and known environmental stressors accelerating disease expression. Our results implicate a primary predisposing skin defect affecting melanocyte adhesiveness that, under stress conditions, leads to disappearance of melanocytes and clinical vitiligo. Melanocyte adhesiveness is thus a potential target for therapy aiming at disease stabilization.
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Affiliation(s)
- Roselyne Y Wagner
- Institut Curie, Normal and Pathological Development of Melanocytes, Orsay, France; CNRS UMR3347, Orsay, France; INSERM U1021, Orsay, France; Equipe labellisée, Ligue Nationale contre le Cancer, Orsay, France
| | - Flavie Luciani
- Institut Curie, Normal and Pathological Development of Melanocytes, Orsay, France; CNRS UMR3347, Orsay, France; INSERM U1021, Orsay, France; Equipe labellisée, Ligue Nationale contre le Cancer, Orsay, France
| | - Muriel Cario-André
- Department of Dermatology and Pediatric Dermatology, National Reference Centre for Rare Skin Disorders, Hôpital Saint-André Bordeaux, Bordeaux, France; INSERM U1035, University of Bordeaux, Bordeaux, France
| | - Alain Rubod
- Institut Curie, Normal and Pathological Development of Melanocytes, Orsay, France; CNRS UMR3347, Orsay, France; INSERM U1021, Orsay, France; Equipe labellisée, Ligue Nationale contre le Cancer, Orsay, France
| | - Valérie Petit
- Institut Curie, Normal and Pathological Development of Melanocytes, Orsay, France; CNRS UMR3347, Orsay, France; INSERM U1021, Orsay, France; Equipe labellisée, Ligue Nationale contre le Cancer, Orsay, France
| | - Laila Benzekri
- Department of Dermatology, Mohammed V University, UFR of Dermatology, Rabat, Morocco
| | - Khaled Ezzedine
- Department of Dermatology and Pediatric Dermatology, National Reference Centre for Rare Skin Disorders, Hôpital Saint-André Bordeaux, Bordeaux, France; INSERM U1035, University of Bordeaux, Bordeaux, France
| | - Sébastien Lepreux
- Department of Pathology, Bordeaux University Hospital, Bordeaux, France
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - A Taieb
- Department of Dermatology and Pediatric Dermatology, National Reference Centre for Rare Skin Disorders, Hôpital Saint-André Bordeaux, Bordeaux, France; INSERM U1035, University of Bordeaux, Bordeaux, France
| | - Yvon Gauthier
- Department of Dermatology and Pediatric Dermatology, National Reference Centre for Rare Skin Disorders, Hôpital Saint-André Bordeaux, Bordeaux, France
| | - Lionel Larue
- Institut Curie, Normal and Pathological Development of Melanocytes, Orsay, France; CNRS UMR3347, Orsay, France; INSERM U1021, Orsay, France; Equipe labellisée, Ligue Nationale contre le Cancer, Orsay, France.
| | - Véronique Delmas
- Institut Curie, Normal and Pathological Development of Melanocytes, Orsay, France; CNRS UMR3347, Orsay, France; INSERM U1021, Orsay, France; Equipe labellisée, Ligue Nationale contre le Cancer, Orsay, France
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Praetorius C, Sturm RA, Steingrimsson E. Sun-induced freckling: ephelides and solar lentigines. Pigment Cell Melanoma Res 2014; 27:339-50. [DOI: 10.1111/pcmr.12232] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 02/06/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Christian Praetorius
- Department of Biochemistry and Molecular Biology; Biomedical Center; Faculty of Medicine; University of Iceland; Reykjavik Iceland
| | - Richard A. Sturm
- Melanogenix Group; Institute for Molecular Bioscience; The University of Queensland; Brisbane Qld Australia
- Dermatology Research Centre; School of Medicine; The University of Queensland; Princess Alexandra Hospital; Brisbane Qld Australia
| | - Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology; Biomedical Center; Faculty of Medicine; University of Iceland; Reykjavik Iceland
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Praetorius C, Grill C, Stacey SN, Metcalf AM, Gorkin DU, Robinson KC, Van Otterloo E, Kim RSQ, Bergsteinsdottir K, Ogmundsdottir MH, Magnusdottir E, Mishra PJ, Davis SR, Guo T, Zaidi MR, Helgason AS, Sigurdsson MI, Meltzer PS, Merlino G, Petit V, Larue L, Loftus SK, Adams DR, Sobhiafshar U, Emre NCT, Pavan WJ, Cornell R, Smith AG, McCallion AS, Fisher DE, Stefansson K, Sturm RA, Steingrimsson E. A polymorphism in IRF4 affects human pigmentation through a tyrosinase-dependent MITF/TFAP2A pathway. Cell 2014; 155:1022-33. [PMID: 24267888 DOI: 10.1016/j.cell.2013.10.022] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 08/19/2013] [Accepted: 10/01/2013] [Indexed: 10/26/2022]
Abstract
Sequence polymorphisms linked to human diseases and phenotypes in genome-wide association studies often affect noncoding regions. A SNP within an intron of the gene encoding Interferon Regulatory Factor 4 (IRF4), a transcription factor with no known role in melanocyte biology, is strongly associated with sensitivity of skin to sun exposure, freckles, blue eyes, and brown hair color. Here, we demonstrate that this SNP lies within an enhancer of IRF4 transcription in melanocytes. The allele associated with this pigmentation phenotype impairs binding of the TFAP2A transcription factor that, together with the melanocyte master regulator MITF, regulates activity of the enhancer. Assays in zebrafish and mice reveal that IRF4 cooperates with MITF to activate expression of Tyrosinase (TYR), an essential enzyme in melanin synthesis. Our findings provide a clear example of a noncoding polymorphism that affects a phenotype by modulating a developmental gene regulatory network.
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Affiliation(s)
- Christian Praetorius
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, 101 Reykjavik, Iceland
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Steingrimsson E. Neal G. Copeland and Nancy A. Jenkins. Pigment Cell Melanoma Res 2013. [DOI: 10.1111/pcmr.12042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eirikur Steingrimsson
- Department of Biochemistry and Molecular Biology; Faculty of Medicine; University of Iceland; Reykjavik; Iceland
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Phung B, Sun J, Schepsky A, Steingrimsson E, Rönnstrand L. Abstract 3093: Elucidation of c-KIT- dependent signaling to MITF. Cancer Res 2012. [DOI: 10.1158/1538-7445.am2012-3093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
MITF, the master regulator of melanocytes, is a basic basic- helix- loop-helix- leucine zipper transcription factor that is essential for the development of melanocytes. MITF is also a lineage- survival oncogene in melanoma and recently, it has been shown that germline mutations in MITF predispose to this malignant disease. In melanoma, MITF has been proposed to act as a rheostat where high levels of MITF contribute to a proliferative phenotype whereas low levels result in a more invasive phenotype. The biological output generated by high or low levels of MITF is well characterized. However, how the activity of MITF is regulated to mediate these effects is less well known. It has been proposed that MITF is phosphorylated upon ligand induced activation of the receptor tyrosine kinase c- KIT. C-KIT engages the MAP kinase signaling cascade where ERK2 directly phosphorylates Ser73 of MITF and P90RSK phosphorylates the Ser409 residue of MITF. As a consequence, MITF activity increases and the protein is subjected to ubiquitin dependent degradation.Here, we show for the first time that c-KIT induces phosphorylation of MITF through the survival PI3 kinase- AKT pathway, the P38 stress pathway as well as the well-known MAP kinase-ERK signaling pathway. In addition, we show that the SRC kinase upstream of ERK is essential for c-KIT induced MITF activation. Moreover, we used several c-KIT phosphorylation site mutants to map the specific sites that are involved in the mediating transcription activation potential of MITF. These mutants also show less effects on MITF-mediated proliferation.We have generated phosphorylation specific antibodies against Ser73 and Ser409 of MITF and characterized the phosphorylation pattern of MITF using these reagents. Our results suggest that there is a particular relationship between Ser73 and Ser409 with subsequent effects on function. Based on our findings, we propose that phosphorylation of MITF might act as negative feedback mechanism that keeps MITF activity in check. Our model challenges the current knowledge of MITF modulation and provides insights that may have a profound impact on our understanding of the role of MITF in melanocyte and melanoma biology.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3093. doi:1538-7445.AM2012-3093
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Pogenberg V, Ogmundsdottir MH, Bergsteinsdottir K, Milewski M, Deineko V, Phung B, Schepsky A, Hoek K, Wilmanns M, Steingrimsson E. Abstract 2221: Dimerization and DNA binding specificities unravelled by the structure of MITF. Cancer Res 2012. [DOI: 10.1158/1538-7445.am2012-2221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The regulatory protein MITF (microphthalmia associated transcription factor) is essential for melanocyte development and acts as a master regulator of this cell type. Mice carrying loss-of-function mutations in Mitf lack melanocytes altogether and in humans, MITF mutations result in the pigmentation and deafness syndromes Waardenburg and Tietz. In melanoma, MITF plays a critical role as a lineage-survival oncogene and may act as a molecular switch downstream of the Braf pathway, determining whether the cells proliferate or form metastasis. Here we describe the crystal structure of MITF in presence and absence of DNA and use complementary functional experiments to show that Isoleucine 212 of the basic region is critical for discriminating between target sequences. The structures also reveal a kink between the second helix and the Leucine Zipper of MITF which has not been described in other related proteins. This kink is due to a shift in the heptad repeats of the Zipper region and is important for selection of dimerization partners. Our results provide new and important insights into the mechamisms of MITF mediated transcription regulation.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2221. doi:1538-7445.AM2012-2221
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Affiliation(s)
| | | | | | | | | | | | | | - Keith Hoek
- 3University Hospital of Zurich, Zurich, Switzerland
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Phung B, Sun J, Schepsky A, Steingrimsson E, Rönnstrand L. C-KIT signaling depends on microphthalmia-associated transcription factor for effects on cell proliferation. PLoS One 2011; 6:e24064. [PMID: 21887372 PMCID: PMC3161112 DOI: 10.1371/journal.pone.0024064] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 08/04/2011] [Indexed: 11/18/2022] Open
Abstract
The development of melanocytes is regulated by the tyrosine kinase receptor c-KIT and the basic-helix-loop-helix-leucine zipper transcription factor Mitf. These essential melanocyte survival regulators are also well known oncogenic factors in malignant melanoma. Despite their importance, not much is known about the regulatory mechanisms and signaling pathways involved. In this study, we therefore sought to identify the signaling pathways and mechanisms involved in c-KIT mediated regulation of Mitf. We report that c-KIT stimulation leads to the activation of Mitf specifically through the c-KIT phosphorylation sites Y721 (PI3 kinase binding site), Y568 and Y570 (Src binding site). Our study not only confirms the involvement of Ras-Erk signaling pathway in the activation of Mitf, but also establishes that Src kinase binding to Y568 and Y570 of c-KIT is required. Using specific inhibitors we observe and verify that c-KIT induced activation of Mitf is dependent on PI3-, Akt-, Src-, p38- or Mek kinases. Moreover, the proliferative effect of c-KIT is dependent on Mitf in HEK293T cells. In contrast, c-KIT Y568F and Y721F mutants are less effective in driving cell proliferation, compared to wild type c-KIT. Our results reveal novel mechanisms by which c-KIT signaling regulates Mitf, with implications for understanding both melanocyte development and melanoma.
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Affiliation(s)
- Bengt Phung
- Wallenberg Laboratory, Experimental Clinical Chemistry, Department of Laboratory Medicine, Lund University, Skåne University Hospital, Malmö, Sweden.
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25
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Pogenberg V, Milewski M, Deineko V, Schepsky A, Steingrimsson E, Wilmanns M. The particular mechanisms of DNA recognition and dimerization of MITF. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311082584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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26
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Sigurdsson MI, Jamshidi N, Steingrimsson E, Thiele I, Palsson BØ. A detailed genome-wide reconstruction of mouse metabolism based on human Recon 1. BMC Syst Biol 2010; 4:140. [PMID: 20959003 PMCID: PMC2978158 DOI: 10.1186/1752-0509-4-140] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 10/19/2010] [Indexed: 12/16/2022]
Abstract
BACKGROUND Well-curated and validated network reconstructions are extremely valuable tools in systems biology. Detailed metabolic reconstructions of mammals have recently emerged, including human reconstructions. They raise the question if the various successful applications of microbial reconstructions can be replicated in complex organisms. RESULTS We mapped the published, detailed reconstruction of human metabolism (Recon 1) to other mammals. By searching for genes homologous to Recon 1 genes within mammalian genomes, we were able to create draft metabolic reconstructions of five mammals, including the mouse. Each draft reconstruction was created in compartmentalized and non-compartmentalized version via two different approaches. Using gap-filling algorithms, we were able to produce all cellular components with three out of four versions of the mouse metabolic reconstruction. We finalized a functional model by iterative testing until it passed a predefined set of 260 validation tests. The reconstruction is the largest, most comprehensive mouse reconstruction to-date, accounting for 1,415 genes coding for 2,212 gene-associated reactions and 1,514 non-gene-associated reactions.We tested the mouse model for phenotype prediction capabilities. The majority of predicted essential genes were also essential in vivo. However, our non-tissue specific model was unable to predict gene essentiality for many of the metabolic genes shown to be essential in vivo. Our knockout simulation of the lipoprotein lipase gene correlated well with experimental results, suggesting that softer phenotypes can also be simulated. CONCLUSIONS We have created a high-quality mouse genome-scale metabolic reconstruction, iMM1415 (Mus Musculus, 1415 genes). We demonstrate that the mouse model can be used to perform phenotype simulations, similar to models of microbe metabolism. Since the mouse is an important experimental organism, this model should become an essential tool for studying metabolic phenotypes in mice, including outcomes from drug screening.
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Affiliation(s)
- Martin I Sigurdsson
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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Phung B, Schepsky A, Steingrimsson E, Rönnstrand L. Abstract 3953: C-Kit and Mitf signaling: Novel involvement of the PI3K/Akt and p38 pathways. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-3953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The development of melanocyte from melanoblast is regulated by the tyrosine kinase receptor c-Kit and the basic-helix-loop-heliz-leucine zipper transcription factor Mitf. It is established that Mitf activity is controlled by c-Kit activation and subsequent phosphorylation of the Erk/Mapk pathway. Serine phosphorylation (activation) of Mitf not only leads to upregulation of Mitf target gene expression but also ubiquitin dependent proteosomal degradation of Mitf. There is little knowledge surrounding the dysregulation between c-Kit and Mitf signaling that is often found in melanocyte progression to melanoma. The aim of our study is, therefore, to identify the signal transduction pathways involved in c-Kit mediated regulation of Mitf.
In our study, we found c-Kit tyrosine phosphorylation sites and novel signaling pathways involved in the regulation of Mitf. Phosphorylation of c-Kit at Tyr721 has been shown to activate the PI3K pathway and Tyr568 and Tyr568/570 are responsible for Src kinase mediated activation of Erk/Mapk pathway. We demonstrate that Y721F, Y568F and Y568/570F mutation of c-Kit prevented Mitf mobility shift, indicating that these tyrosine phosphorylation sites are involved in Mitf regulation. Further, we observe that treatment of c-Kit and Mitf transfected HEK293T cells with LY294002 (PI3K inhib.), Akt IV (Akt inhib.), SU6656 (Src kinase inhib.), SB203580 (p38 inhib.) or U0126 (Mek inhib.) prevented c-Kit mediated Mitf mobility shift. Similar results were also observed in the murine melanocyte, Melan- A cell line where Mitf and c-Kit are endogenously expressed. In order to further verify c-Kit's role as Mitf regulator, we examined tyrosinase (downstream target of Mitf) promoter activity using a luciferase reporter construct. Ligand stimulation of c-Kit increased the Mitf target promoter activity.
In conclusion, for the first time, we demonstrate that the signal transduction between c-Kit and Mitf is dependent on, 1) c-Kit Tyr721/PI3K/Akt pathway, 2) p38 pathway and 3) c-Kit Tyr568 or Tyr568/570 / Src kinase mediated Erk pathway. C-Kit activation leading to downstream were also shown to promote the transcriptional activity of Mitf. Our results reveal novel mechanisms by which c-Kit signaling regulates Mitf, with implication for understanding of both melanocyte development and melanoma.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3953.
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Hoek KS, Schlegel NC, Eichhoff OM, Widmer DS, Praetorius C, Einarsson SO, Valgeirsdottir S, Bergsteinsdottir K, Schepsky A, Dummer R, Steingrimsson E. Novel MITF targets identified using a two-step DNA microarray strategy. Pigment Cell Melanoma Res 2009; 21:665-76. [PMID: 19067971 DOI: 10.1111/j.1755-148x.2008.00505.x] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Malignant melanoma is a chemotherapy-resistant cancer with high mortality. Recent advances in our understanding of the disease at the molecular level have indicated that it shares many characteristics with developmental precursors to melanocytes, the mature pigment-producing cells of the skin and hair follicles. The development of melanocytes absolutely depends on the action of the microphthalmia-associated transcription factor (MITF). MITF has been shown to regulate a broad variety of genes, whose functions range from pigment production to cell-cycle regulation, migration and survival. However, the existing list of targets is not sufficient to explain the role of MITF in melanocyte development and melanoma progression. DNA microarray analysis of gene expression offers a straightforward approach to identify new target genes, but standard analytical procedures are susceptible to the generation of false positives and require additional experimental steps for validation. Here, we introduce a new strategy where two DNA microarray-based approaches for identifying transcription factor targets are combined in a cross-validation protocol designed to help control false-positive generation. We use this two-step approach to successfully re-identify thirteen previously recorded targets of MITF-mediated upregulation, as well as 71 novel targets. Many of these new targets have known relevance to pigmentation and melanoma biology, and further emphasize the critical role of MITF in these processes.
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Affiliation(s)
- Keith S Hoek
- Department of Dermatology, University Hospital of Zürich, Zürich, Switzerland.
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Steingrimsson E. The MITF transcription factor in melanocyte development. Exp Dermatol 2006. [DOI: 10.1111/j.1600-0625.2006.00498.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schepsky A, Bruser K, Gunnarsson GJ, Goodall J, Hallsson JH, Goding CR, Steingrimsson E, Hecht A. The microphthalmia-associated transcription factor Mitf interacts with beta-catenin to determine target gene expression. Mol Cell Biol 2006; 26:8914-27. [PMID: 17000761 PMCID: PMC1636837 DOI: 10.1128/mcb.02299-05] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Commitment to the melanocyte lineage is characterized by the onset of expression of the microphthalmia-associated transcription factor (Mitf). This transcription factor plays a fundamental role in melanocyte development and maintenance and seems to be crucial for the survival of malignant melanocytes. Furthermore, Mitf has been shown to be involved in cell cycle regulation and to play important functions in self-renewal and maintenance of melanocyte stem cells. Although little is known about how Mitf regulates these various processes, one possibility is that Mitf interacts with other regulators. Here we show that Mitf can interact directly with beta-catenin, the key mediator of the canonical Wnt signaling pathway. The Wnt signaling pathway plays a critical role in melanocyte development and is intimately involved in triggering melanocyte stem cell proliferation. Significantly, constitutive activation of this pathway is a feature of a number of cancers including malignant melanoma. Here we show that Mitf can redirect beta-catenin transcriptional activity away from canonical Wnt signaling-regulated genes toward Mitf-specific target promoters to activate transcription. Thus, by a feedback mechanism, Mitf can diversify the output of canonical Wnt signaling to enhance the repertoire of genes regulated by beta-catenin. Our results reveal a novel mechanism by which Wnt signaling and beta-catenin activate gene expression, with significant implications for our understanding of both melanocyte development and melanoma.
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Affiliation(s)
- Alexander Schepsky
- Biochemistry and Molecular Biology, Faculty of Medicine, University of Iceland, Vatnsmyrarvegur 16, 101 Reykjavik, Iceland
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Bataillon T, Mailund T, Thorlacius S, Steingrimsson E, Rafnar T, Halldorsson MM, Calian V, Schierup MH. The effective size of the Icelandic population and the prospects for LD mapping: inference from unphased microsatellite markers. Eur J Hum Genet 2006; 14:1044-53. [PMID: 16736029 DOI: 10.1038/sj.ejhg.5201669] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Characterizing the extent of linkage disequilibrium (LD) in the genome is a pre-requisite for association mapping studies. Patterns of LD also contain information about the past demography of populations. In this study, we focus on the Icelandic population where LD was investigated in 12 regions of approximately 15 cM using regularly spaced microsatellite loci displaying high heterozygosity. A total of 1753 individuals were genotyped for 179 markers. LD was estimated using a composite disequilibrium measure based on unphased data. LD decreases with distance in all 12 regions and more LD than expected by chance can be detected over approximately 4 cM in our sample. Differences in the patterns of decrease of LD with distance among genomic regions were mostly due to two regions exhibiting, respectively, higher and lower proportions of pairs in LD than average within the first 4 cM. We pooled data from all regions, except these two and summarized patterns of LD by computing the proportion of pairs of loci exhibiting significant LD (at the 5% level) as a function of distance. We compared observed patterns of LD with simulated data sets obtained under scenarios with varying demography and intensity of recombination. We show that unphased data allow to make inferences on scaled recombination rates from patterns of LD. Patterns of LD in Iceland suggest a genome-wide scaled recombination rate of rho* = 200 (130-330) per cM (or an effective size of roughly 5000), in the low range of estimates recently reported in three populations from the HapMap project.
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Affiliation(s)
- Thomas Bataillon
- Bioinformatics Research Center, University of Aarhus, Høegh-Guldbergs Gade 10, DK-8000 Aarhus C, Denmark.
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Eldon BJ, Thorlacius S, Jonsson T, Jonasson JG, Kjartansson J, Bodvarsson S, Steingrimsson E, Rafnar T. A population-based study on the familial aggregation of cutaneous malignant melanoma in Iceland. Eur J Cancer 2006; 42:922-6. [PMID: 16530404 DOI: 10.1016/j.ejca.2005.11.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 11/16/2005] [Accepted: 11/21/2005] [Indexed: 01/19/2023]
Abstract
The aim of this study was to characterize the familial nature of cutaneous malignant melanoma (CMM) in Iceland. Risk ratio was used to estimate the risk among relatives of all CMM index cases diagnosed in Iceland over a 45-year period (1955-1999), using data from the National Cancer Registry and a genealogy database that covers the whole of Iceland's population. First-, second-, and third-degree relatives of CMM patients did not have an increased risk of the disease, and no added risk of other types of cancer among relatives was observed, except for thyroid cancer in first-degree male relatives. Seven individuals were diagnosed with two or more primary CMM in this period; none of these individuals had a first or second-degree relative with CMM. Altogether, 2.4% of cases were familial, as defined by commonly used criteria. In conclusion, high-penetrance susceptibility genes do not contribute much to CMM in the Icelandic population. The great majority of CMM cases in Iceland are most likely caused by the interplay between environmental causes and low-risk genes.
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Stefansson T, Moller PH, Sigurdsson F, Steingrimsson E, Eldon BJ. Familial risk of colon and rectal cancer in Iceland: Evidence for different etiologic factors? Int J Cancer 2006; 119:304-8. [PMID: 16477631 DOI: 10.1002/ijc.21835] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aim of this study was to characterize the familial risk of colon and rectal cancer using 2 population-based registries in Iceland, the Icelandic Cancer Registry and a genealogy database. The standardized incidence ratio (SIR) was used to estimate the risk among relatives of colorectal cancer index cases diagnosed in Iceland over a 46-year period (1955-2000). The 2,770 colorectal cancer patients had 23,272 first-degree relatives. Among first-degree relatives, there was an increased risk of both colon (SIR 1.47, 95% confidence interval (CI) 1.34-1.62) and rectal cancer (SIR 1.24, 95% CI 1.04-1.47). An increased risk of colon cancer was observed among siblings of colon cancer patients (SIR 2.03, 95% CI 1.76-2.33), whereas no such increase was observed for parents or offspring. Furthermore, the risk of rectal cancer was only increased among brothers (SIR 2.46 95% CI 1.46-3.89) of rectal cancer patients and not among their sisters (SIR 1.0 95% CI 0.40-2.06). The added risk of colon cancer among first-degree relatives was independent of site of colon cancer in the proband. Our results confirm that family history of colorectal cancer is a risk factor for the disease. However, family history has a different association with colon cancer than with rectal cancer, suggesting that the 2 cancer types may have different etiologic factors. Our results have implications for colon and rectal cancer screening programs.
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Affiliation(s)
- Tryggvi Stefansson
- Department of Surgery, Landspitali University Hospital, Reykjavik, Iceland.
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Rehli M, Sulzbacher S, Pape S, Ravasi T, Wells CA, Heinz S, Söllner L, El Chartouni C, Krause SW, Steingrimsson E, Hume DA, Andreesen R. Transcription factor Tfec contributes to the IL-4-inducible expression of a small group of genes in mouse macrophages including the granulocyte colony-stimulating factor receptor. J Immunol 2005; 174:7111-22. [PMID: 15908341 DOI: 10.4049/jimmunol.174.11.7111] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Expression of the mouse transcription factor EC (Tfec) is restricted to the myeloid compartment, suggesting a function for Tfec in the development or function of these cells. However, mice lacking Tfec develop normally, indicating a redundant role for Tfec in myeloid cell development. We now report that Tfec is specifically induced in bone marrow-derived macrophages upon stimulation with the Th2 cytokines, IL-4 and IL-13, or LPS. LPS induced a rapid and transient up-regulation of Tfec mRNA expression and promoter activity, which was dependent on a functional NF-kappaB site. IL-4, however, induced a rapid, but long-lasting, increase in Tfec mRNA, which, in contrast to LPS stimulation, also resulted in detectable levels of Tfec protein. IL-4-induced transcription of Tfec was absent in macrophages lacking Stat6, and its promoter depended on two functional Stat6-binding sites. A global comparison of IL-4-induced genes in both wild-type and Tfec mutant macrophages revealed a surprisingly mild phenotype with only a few genes affected by Tfec deficiency. These included the G-CSFR (Csf3r) gene that was strongly up-regulated by IL-4 in wild-type macrophages and, to a lesser extent, in Tfec mutant macrophages. Our study also provides a general definition of the transcriptome in alternatively activated mouse macrophages and identifies a large number of novel genes characterizing this cell type.
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Affiliation(s)
- Michael Rehli
- Department of Hematology and Oncology, University of Regensburg, Germany.
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Rafnar T, Benediktsdottir KR, Eldon BJ, Gestsson T, Saemundsson H, Olafsson K, Salvarsdottir A, Steingrimsson E, Thorlacius S. BRCA2, but not BRCA1, mutations account for familial ovarian cancer in Iceland: a population-based study. Eur J Cancer 2005; 40:2788-93. [PMID: 15571962 DOI: 10.1016/j.ejca.2004.09.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 08/27/2004] [Accepted: 09/07/2004] [Indexed: 01/08/2023]
Abstract
A single founder mutation in each of the BRCA genes has been identified in Iceland. The frequency of the BRCA1 G5193A and BRCA2 999del5 mutations in all ovarian cancer patients diagnosed over the period 1991-2000 was determined. Mutation status was correlated with family history, tumour morphology and age at diagnosis. Samples from 86% of cases (179 carcinomas and 74 borderline tumours) were available. In the carcinomas, BRCA1 and BRCA2 mutations were present in 1.2% and 6% of cases, respectively. No BRCA mutations were found in the borderline tumours. Odds Ratio (OR) of developing ovarian cancer was 20.65 for BRCA2 carriers. Family history of breast/ovarian cancer was present for 70% of BRCA2 carriers and approximately 14% for non-carriers with carcinoma. In conclusion, BRCA2 999del5 is present in 6% of ovarian cancer cases in Iceland and is associated with a 20-fold increase in the risk of the disease. The BRCA1 G5193A mutation is too rare to contribute significantly to ovarian cancer in Iceland.
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Affiliation(s)
- Thorunn Rafnar
- Iceland Genomics Corporation, Snorrabraut 60, 105 Reykjavik, Iceland.
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Rafnar T, Thorlacius S, Steingrimsson E, Schierup MH, Madsen JN, Calian V, Eldon BJ, Jonsson T, Hein J, Thorgeirsson SS. The Icelandic Cancer Project--a population-wide approach to studying cancer. Nat Rev Cancer 2004; 4:488-92. [PMID: 15170451 DOI: 10.1038/nrc1371] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Thorunn Rafnar
- Iceland Genomics Corporation, Snorrabraut 60, 105 Reykjavik, Iceland
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Kristinsson SY, Thorolfsdottir ET, Talseth B, Steingrimsson E, Thorsson AV, Helgason T, Hreidarsson AB, Arngrimsson R. MODY in Iceland is associated with mutations in HNF-1alpha and a novel mutation in NeuroD1. Diabetologia 2001; 44:2098-103. [PMID: 11719843 DOI: 10.1007/s001250100016] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS Five different types of maturity-onset diabetes of the young (MODY) have been identified until now but mutation screening suggests that more MODY genes exist. Mutations in genes encoding transcription factors essential for normal development and function of pancreatic beta cells has recently become important in studying the genetics of Type II (non-insulin-dependent) diabetes mellitus. Patients with MODY and their families in Iceland were screened for mutations in the transcription factor genes. METHODS Clinical and biochemical information on individuals with MODY was collected and their family trees constructed. Linkage analysis was carried out on chromosomal regions known to harbour genes previously shown to be associated with MODY. Mutations were identified by direct sequencing. RESULTS Three families were identified. Two of these showed linkage to chromosome 12 and carried mutations in exon 4 of the HNF-1alpha gene (290fsdelC and R272C). However, the third family showed no linkage to the previously described MODY genes but shared a novel mutation in the NeuroD1 gene on chromosome 2q32. This mutation, a glutamate to lysine substitution at codon 110, resides in the basic domain of the protein. CONCLUSION/INTERPRETATION Mutations in MODY subjects have been identified in the Icelandic population. In addition this study identified the NeuroD1 gene as the gene responsible for the sixth type of MODY.
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Affiliation(s)
- S Y Kristinsson
- Unit of Medical Genetics, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
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Mao NC, Steingrimsson E, DuHadaway J, Wasserman W, Ruiz JC, Copeland NG, Jenkins NA, Prendergast GC. The murine Bin1 gene functions early in myogenesis and defines a new region of synteny between mouse chromosome 18 and human chromosome 2. Genomics 1999; 56:51-8. [PMID: 10036185 DOI: 10.1006/geno.1998.5709] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We cloned and functionally characterized the murine Bin1 gene as a first step to investigate its physiological roles in differentiation, apoptosis, and tumorigenesis. The exon-intron organization of the >/=55-kb gene is similar to that of the human gene. Consistent with a role for Bin1 in apoptosis, the promoter included a functional consensus motif for activation by NF-kappaB, an important regulator of cell death. A muscle regulatory module defined in the human promoter that includes a consensus recognition site for myoD family proteins was not conserved in the mouse promoter. However, Bin1 is upregulated in embryonic development by E10.5 in myotomes, the progenitors of skeletal muscle, supporting a role in myogenesis and suggesting that the mouse and human genes may be controlled somewhat differently during development. In C2C12 myoblasts antisense Bin1 prevents induction of the cell cycle kinase inhibitor p21WAF1, suggesting that it acts at an early time during the muscle differentiation program. Interspecific mouse backcross mapping located the Bin1 locus between Mep1b and Apc on chromosome 18. Since the human gene was mapped previously to chromosome 2q14, the location of Bin1 defines a previously unrecognized region of synteny between human chromosome 2 and mouse chromosome 18.
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Affiliation(s)
- N C Mao
- The Wistar Institute, 3601 Spruce Street, Philadelphia, Pennsylvania, 19104, USA
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Tamimi RM, Steingrimsson E, Montgomery-Dyer K, Copeland NG, Jenkins NA, Tapscott SJ. NEUROD2 and NEUROD3 genes map to human chromosomes 17q12 and 5q23-q31 and mouse chromosomes 11 and 13, respectively. Genomics 1997; 40:355-7. [PMID: 9119405 DOI: 10.1006/geno.1996.4578] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
NEUROD2 and NEUROD3 are transcription factors involved in neurogenesis that are related to the basic helix-loop-helix protein NEUROD. NEUROD2 maps to human chromosome 17q12 and mouse chromosome 11. NEUROD3 maps to human chromosome 5q23-q31 and mouse chromosome 13.
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Affiliation(s)
- R M Tamimi
- Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA
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Tamimi R, Steingrimsson E, Copeland NG, Dyer-Montgomery K, Lee JE, Hernandez R, Jenkins NA, Tapscott SJ. The NEUROD gene maps to human chromosome 2q32 and mouse chromosome 2. Genomics 1996; 34:418-21. [PMID: 8786144 DOI: 10.1006/geno.1996.0306] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The Neurod gene is a basic-helix-loop-helix gene that regulates neurogenesis and is identical to the hamster beta2 gene that was cloned as a regulator of insulin transcription. Here we report the cloning of human NEUROD and mapping of the gene to human chromosome 2q32 and to mouse chromosome 2.
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Affiliation(s)
- R Tamimi
- Fred Hutchinson Cancer Research Center, 1124 Columbia Street, Seattle, Washington, 98104, USA
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Cross JC, Flannery ML, Blanar MA, Steingrimsson E, Jenkins NA, Copeland NG, Rutter WJ, Werb Z. Hxt encodes a basic helix-loop-helix transcription factor that regulates trophoblast cell development. Development 1995; 121:2513-23. [PMID: 7671815 DOI: 10.1242/dev.121.8.2513] [Citation(s) in RCA: 230] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Trophoblast cells are the first lineage to form in the mammalian conceptus and mediate the process of implantation. We report the cloning of a basic helix-loop-helix (bHLH) transcription factor gene, Hxt, that is expressed in early trophoblast and in differentiated giant cells. A separate gene, Hed, encodes a related protein that is expressed in maternal deciduum surrounding the implantation site. Overexpression of Hxt in mouse blastomeres directed their development into trophoblast cells in blastocysts. In addition, overexpression of Hxt induced the differentiation of rat trophoblast (Rcho-1) stem cells as assayed by changes in cell adhesion and by activation of the placental lactogen-I gene promoter, a trophoblast giant cell-specific gene. In contrast, the negative HLH regulator, Id-1, inhibited Rcho-1 differentiation and placental lactogen-I transcription. These data demonstrate a role for HLH factors in regulating trophoblast development and indicate a positive role for Hxt in promoting the formation of trophoblast giant cells.
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Affiliation(s)
- J C Cross
- Department of Anatomy, University of California, San Francisco 94143, USA
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Abstract
At the poles of the Drosophila embryo, cell fate is established by a pathway that begins with the activation of a membrane-associated tyrosine kinase (the torso gene product); this then leads to activation of a serine/threonine kinase (Drosophila Raf-1). Activated Raf-1 then leads, by an undefined mechanism, to the transcriptional activation of the tailless (tll) gene; the tll gene product, itself a transcription factor, subsequently regulates the expression of an array of target genes. To further define this pathway, we have utilized sequence comparison between Drosophila melanogaster and Drosophila virilis to identify conserved elements in the tll promoter region. As assessed by DNase I footprinting and promoter dissection experiments, two of these elements are potential regulatory targets of Raf-1-activated transcription factors. Sequence comparison also reveals that the unique residues in the DNA-binding domain of the tll protein, the next component in the pathway, are conserved. One of these residues, the alanine after the last cysteine in the first zinc finger, may be responsible for part of the difference between the tll protein DNA binding site and the closely related half-site of the retinoid/estrogen receptors. Consistent with the rapid turnover of the tll protein, it contains a PEST sequence (rich in proline, glutamate and aspartate, serine, and threonine) that is also conserved.
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Affiliation(s)
- G J Liaw
- Department of Biology, University of California, Los Angeles 90024
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