51
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Serpin Facilitates Tumor-Suppressive Cell Competition by Blocking Toll-Mediated Yki Activation in Drosophila. Curr Biol 2018; 28:1756-1767.e6. [DOI: 10.1016/j.cub.2018.04.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 03/06/2018] [Accepted: 04/05/2018] [Indexed: 11/23/2022]
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52
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Fadul J, Rosenblatt J. The forces and fates of extruding cells. Curr Opin Cell Biol 2018; 54:66-71. [PMID: 29727745 DOI: 10.1016/j.ceb.2018.04.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/04/2018] [Accepted: 04/12/2018] [Indexed: 02/07/2023]
Abstract
Cell extrusion drives most epithelial cell death while maintaining a functional epithelial barrier. To extrude, a cell produces a lipid signal that triggers the neighboring cells to reorganize actin and myosin basally to squeeze the extruding cell out apically from the barrier. More studies continue to reveal other signals and mechanisms controlling apical extrusion. New developmental studies are uncovering mechanisms controlling basal extrusion, or ingression, which occurs when apical extrusion is defective or during de-differentiation in development. Here, we review recent advances in epithelial extrusion, focusing particularly on forces exerted upon extruding cells and their various later fates ranging from cell death, normal development, and cancer.
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Affiliation(s)
- John Fadul
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, UT, USA
| | - Jody Rosenblatt
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, UT, USA.
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53
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Modelling Cooperative Tumorigenesis in Drosophila. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4258387. [PMID: 29693007 PMCID: PMC5859872 DOI: 10.1155/2018/4258387] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 01/21/2018] [Indexed: 12/13/2022]
Abstract
The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression.
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54
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Donohoe CD, Csordás G, Correia A, Jindra M, Klein C, Habermann B, Uhlirova M. Atf3 links loss of epithelial polarity to defects in cell differentiation and cytoarchitecture. PLoS Genet 2018; 14:e1007241. [PMID: 29494583 PMCID: PMC5849342 DOI: 10.1371/journal.pgen.1007241] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/13/2018] [Accepted: 02/05/2018] [Indexed: 12/27/2022] Open
Abstract
Interplay between apicobasal cell polarity modules and the cytoskeleton is critical for differentiation and integrity of epithelia. However, this coordination is poorly understood at the level of gene regulation by transcription factors. Here, we establish the Drosophila activating transcription factor 3 (atf3) as a cell polarity response gene acting downstream of the membrane-associated Scribble polarity complex. Loss of the tumor suppressors Scribble or Dlg1 induces atf3 expression via aPKC but independent of Jun-N-terminal kinase (JNK) signaling. Strikingly, removal of Atf3 from Dlg1 deficient cells restores polarized cytoarchitecture, levels and distribution of endosomal trafficking machinery, and differentiation. Conversely, excess Atf3 alters microtubule network, vesicular trafficking and the partition of polarity proteins along the apicobasal axis. Genomic and genetic approaches implicate Atf3 as a regulator of cytoskeleton organization and function, and identify Lamin C as one of its bona fide target genes. By affecting structural features and cell morphology, Atf3 functions in a manner distinct from other transcription factors operating downstream of disrupted cell polarity. Epithelial cells form sheets and line both the outside and inside of our body. Their proper development and function require the asymmetric distribution of cellular components from the top to the bottom, known as apicobasal polarization. As loss of polarity hallmarks a majority of cancers in humans, understanding how epithelia respond to a collapse of the apicobasal axis is of great interest. Here, we show that in the fruit fly Drosophila melanogaster the breakdown of epithelial polarity engages Activating transcription factor 3 (Atf3), a protein that directly binds the DNA and regulates gene expression. We demonstrate that many of the pathological consequences of disturbed polarity require Atf3, as its loss in this context results in normalization of cellular architecture, vesicle trafficking and differentiation. Using unbiased genome-wide approaches we identify the genetic program controlled by Atf3 and experimentally verify select candidates. Given the evolutionary conservation of Atf3 between flies and man, we believe that our findings in the Drosophila model will contribute to a better understanding of diseases stemming from compromised epithelial polarity.
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Affiliation(s)
- Colin D. Donohoe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Gábor Csordás
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Andreia Correia
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Marek Jindra
- Biology Center, Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Corinna Klein
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail:
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55
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Ohsawa S, Vaughen J, Igaki T. Cell Extrusion: A Stress-Responsive Force for Good or Evil in Epithelial Homeostasis. Dev Cell 2018; 44:284-296. [PMID: 29408235 DOI: 10.1016/j.devcel.2018.01.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 12/31/2022]
Abstract
Epithelial tissues robustly respond to internal and external stressors via dynamic cellular rearrangements. Cell extrusion acts as a key regulator of epithelial homeostasis by removing apoptotic cells, orchestrating morphogenesis, and mediating competitive cellular battles during tumorigenesis. Here, we delineate the diverse functions of cell extrusion during development and disease. We emphasize the expanding role for apoptotic cell extrusion in exerting morphogenetic forces, as well as the strong intersection of cell extrusion with cell competition, a homeostatic mechanism that eliminates aberrant or unfit cells. While cell competition and extrusion can exert potent, tumor-suppressive effects, dysregulation of either critical homeostatic program can fuel cancer progression.
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Affiliation(s)
- Shizue Ohsawa
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - John Vaughen
- Department of Developmental Biology, Stanford School of Medicine, Beckman Center, 279 Campus Drive B300, Stanford, CA 94305, USA
| | - Tatsushi Igaki
- Laboratory of Genetics, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
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56
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Kale A, Ji Z, Kiparaki M, Blanco J, Rimesso G, Flibotte S, Baker NE. Ribosomal Protein S12e Has a Distinct Function in Cell Competition. Dev Cell 2018; 44:42-55.e4. [PMID: 29316439 DOI: 10.1016/j.devcel.2017.12.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/03/2017] [Accepted: 12/04/2017] [Indexed: 10/18/2022]
Abstract
Wild-type Drosophila cells can remove cells heterozygous for ribosomal protein mutations (known as "Minute" mutant cells) from genetic mosaics, a process termed cell competition. The ribosomal protein S12 was unusual because cells heterozygous for rpS12 mutations were not competed by wild-type, and a viable missense mutation in rpS12 protected Minute cells from cell competition with wild-type cells. Furthermore, cells with Minute mutations were induced to compete with one another by altering the gene dose of rpS12, eliminating cells with more rpS12 than their neighbors. Thus RpS12 has a special function in cell competition that defines the competitiveness of cells. We propose that cell competition between wild-type and Minute cells is initiated by a signal of ribosomal protein haploinsufficiency mediated by RpS12. Since competition between cells expressing different levels of Myc did not require RpS12, other kinds of cell competition may be initiated differently.
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Affiliation(s)
- Abhijit Kale
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Zhejun Ji
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Marianthi Kiparaki
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Jorge Blanco
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Gerard Rimesso
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Stephane Flibotte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Nicholas E Baker
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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57
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58
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Pérez E, Lindblad JL, Bergmann A. Tumor-promoting function of apoptotic caspases by an amplification loop involving ROS, macrophages and JNK in Drosophila. eLife 2017; 6:e26747. [PMID: 28853394 PMCID: PMC5779227 DOI: 10.7554/elife.26747] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/28/2017] [Indexed: 01/04/2023] Open
Abstract
Apoptosis and its molecular mediators, the caspases, have long been regarded as tumor suppressors and one hallmark of cancer is 'Evading Apoptosis'. However, recent work has suggested that apoptotic caspases can also promote proliferation and tumor growth under certain conditions. How caspases promote proliferation and how cells are protected from the potentially harmful action of apoptotic caspases is largely unknown. Here, we show that although caspases are activated in a well-studied neoplastic tumor model in Drosophila, oncogenic mutations of the proto-oncogene Ras (RasV12) maintain tumorous cells in an 'undead'-like condition and transform caspases from tumor suppressors into tumor promotors. Instead of killing cells, caspases now promote the generation of intra- and extracellular reactive oxygen species (ROS). One function of the ROS is the recruitment and activation of macrophage-like immune cells which in turn signal back to tumorous epithelial cells to activate oncogenic JNK signaling. JNK further promotes and amplifies caspase activity, thereby constituting a feedback amplification loop. Interfering with the amplification loop strongly reduces the neoplastic behavior of these cells and significantly improves organismal survival. In conclusion, RasV12-modified caspases initiate a feedback amplification loop involving tumorous epithelial cells and macrophage-like immune cells that is necessary for uncontrolled tumor growth and invasive behavior.
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Affiliation(s)
- Ernesto Pérez
- Department of Molecular, Cell and Cancer BiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Jillian L Lindblad
- Department of Molecular, Cell and Cancer BiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
| | - Andreas Bergmann
- Department of Molecular, Cell and Cancer BiologyUniversity of Massachusetts Medical SchoolWorcesterUnited States
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59
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Morimoto K, Tamori Y. Induction and Diagnosis of Tumors in Drosophila Imaginal Disc Epithelia. J Vis Exp 2017. [PMID: 28784954 DOI: 10.3791/55901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In the early stages of cancer, transformed mutant cells show cytological abnormalities, begin uncontrolled overgrowth, and progressively disrupt tissue organization. Drosophila melanogaster has emerged as a popular experimental model system in cancer biology to study the genetic and cellular mechanisms of tumorigenesis. In particular, genetic tools for Drosophila imaginal discs (developing epithelia in larvae) enable the creation of transformed pro-tumor cells within a normal epithelial tissue, a situation similar to the initial stages of human cancer. A recent study of tumorigenesis in Drosophila wing imaginal discs, however, showed that tumor initiation depends on the tissue-intrinsic cytoarchitecture and the local microenvironment, suggesting that it is important to consider the region-specific susceptibility to tumorigenic stimuli in evaluating tumor phenotypes in imaginal discs. To facilitate phenotypic analysis of tumor progression in imaginal discs, here we describe a protocol for genetic experiments using the GAL4-UAS system to induce neoplastic tumors in wing imaginal discs. We further introduce a diagnosis method to classify the phenotypes of clonal lesions induced in imaginal epithelia, as a clear classification method to discriminate various stages of tumor progression (such as hyperplasia, dysplasia, or neoplasia) had not been described before. These methods might be broadly applicable to the clonal analysis of tumor phenotypes in various organs in Drosophila.
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Affiliation(s)
- Kenta Morimoto
- Structural Biology Center, National Institute of Genetics and Department of Genetics, School of Life Science, SOKENDAI; Graduate School of Media and Governance, Keio University
| | - Yoichiro Tamori
- Structural Biology Center, National Institute of Genetics and Department of Genetics, School of Life Science, SOKENDAI;
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60
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Abstract
How aberrant cells are removed from a tissue to prevent tumor formation is a key question in cancer biology. Reporting in this issue of Developmental Cell, Vaughen and Igaki (2016) show that a pathway with an important role in neural guidance also directs extrusion of tumor cells from epithelial tissues.
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Affiliation(s)
- Helena E Richardson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia.
| | - Marta Portela
- Department of Molecular, Cellular, and Developmental Neurobiology, Cajal Institute (CSIC), Avenida Doctor Arce, 37, Madrid 28002, Spain
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61
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Baker NE. Mechanisms of cell competition emerging from Drosophila studies. Curr Opin Cell Biol 2017; 48:40-46. [PMID: 28600967 DOI: 10.1016/j.ceb.2017.05.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/15/2017] [Accepted: 05/16/2017] [Indexed: 10/19/2022]
Abstract
Cell competition was described in Drosophila as the loss from mosaic tissues of otherwise viable cells heterozygous for Ribosomal protein mutations ('Minutes'). Cell competition has now been described to occur between multiple other genotypes, such as cells differing in myc expression levels, or mutated for neoplastic tumor suppressors. Recent studies implicate innate immunity components, and possibly mechanical stress, compression and cell intercalation as a consequence of differential growth rates in competitive cell death. Competition to eliminate pre-neoplastic tumors makes use of signals and receptors also used in patterning the nervous system including Slit/Robo2 and Sas/PTP10D to recognize and extrude clones of mutant cells, at least where local epithelial cyto-architecture is favorable. Cell competition facilitates expansion of Drosophila tumors through host tissue, and in normal development may promote developmental robustness and longevity by selecting for optimal progenitor cells.
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Affiliation(s)
- Nicholas E Baker
- Department of Genetics, Department of Developmental and Molecular Biology, Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States.
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62
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Sallé J, Gervais L, Boumard B, Stefanutti M, Siudeja K, Bardin AJ. Intrinsic regulation of enteroendocrine fate by Numb. EMBO J 2017; 36:1928-1945. [PMID: 28533229 DOI: 10.15252/embj.201695622] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 12/25/2022] Open
Abstract
How terminal cell fates are specified in dynamically renewing adult tissues is not well understood. Here we explore terminal cell fate establishment during homeostasis using the enteroendocrine cells (EEs) of the adult Drosophila midgut as a paradigm. Our data argue against the existence of local feedback signals, and we identify Numb as an intrinsic regulator of EE fate. Our data further indicate that Numb, with alpha-adaptin, acts upstream or in parallel of known regulators of EE fate to limit Notch signaling, thereby facilitating EE fate acquisition. We find that Numb is regulated in part through its asymmetric and symmetric distribution during stem cell divisions; however, its de novo synthesis is also required during the differentiation of the EE cell. Thus, this work identifies Numb as a crucial factor for cell fate choice in the adult Drosophila intestine. Furthermore, our findings demonstrate that cell-intrinsic control mechanisms of terminal cell fate acquisition can result in a balanced tissue-wide production of terminally differentiated cell types.
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Affiliation(s)
- Jérémy Sallé
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Louis Gervais
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Benjamin Boumard
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France.,Département de Biologie, École Normale Supérieure de Lyon, Lyon, France
| | - Marine Stefanutti
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Katarzyna Siudeja
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Allison J Bardin
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France .,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
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63
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Haque F, Kaku Y, Fujimura S, Ohmori T, Adelstein RS, Nishinakamura R. Non-muscle myosin II deletion in the developing kidney causes ureter-bladder misconnection and apical extrusion of the nephric duct lineage epithelia. Dev Biol 2017; 427:121-130. [PMID: 28478097 DOI: 10.1016/j.ydbio.2017.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/27/2017] [Accepted: 04/29/2017] [Indexed: 01/23/2023]
Abstract
In kidney development, connection of the nephric duct (ND) to the cloaca and subsequent sprouting of the ureteric bud (UB) from the ND are important for urinary exit tract formation. Although the roles of Ret signaling are well established, it remains unclear how intracellular cytoskeletal proteins regulate these morphogenetic processes. Myh9 and Myh10 encode two different non-muscle myosin II heavy chains, and Myh9 mutations in humans are implicated in congenital kidney diseases. Here we report that ND/UB lineage-specific deletion of Myh9/Myh10 in mice caused severe hydroureter/hydronephrosis at birth. At mid-gestation, the mutant ND/UB epithelia exhibited aberrant basal protrusion and ectopic UB formation, which likely led to misconnection of the ureter to the bladder. In addition, the mutant epithelia exhibited apical extrusion followed by massive apoptosis in the lumen, which could be explained by reduced apical constriction and intercellular adhesion mediated by E-cadherin. These phenotypes were not ameliorated by genetic reduction of the tyrosine kinase receptor Ret. In contrast, ERK was activated in the mutant cells and its chemical inhibition partially ameliorated the phenotypes. Thus, myosin II is essential for maintaining the apicobasal integrity of the developing kidney epithelia independently of Ret signaling.
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Affiliation(s)
- Fahim Haque
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Yusuke Kaku
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Sayoko Fujimura
- Liaison Laboratory Research Promotion Center, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Tomoko Ohmori
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Robert S Adelstein
- Laboratory of Molecular Cardiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ryuichi Nishinakamura
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan.
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64
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Tamori Y, Deng WM. Tissue-Intrinsic Tumor Hotspots: Terroir for Tumorigenesis. Trends Cancer 2017; 3:259-268. [PMID: 28718438 DOI: 10.1016/j.trecan.2017.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/04/2017] [Accepted: 03/07/2017] [Indexed: 12/26/2022]
Abstract
Epithelial tissues are highly organized systems with a remarkable homeostatic ability to maintain morphology through regulation of cellular proliferation and tissue integrity. This robust self-organizing system is progressively disrupted during tumor development. Recent studies of conserved tumor-suppressor genes in Drosophila showed how protumor cells deviate from the robustly organized tissue microenvironment to take the first steps into becoming aggressive tumors. Here we review the 'tumor hotspot' hypothesis that explains how the tissue-intrinsic local microenvironment has a pivotal role in the initial stage of tumorigenesis in Drosophila epithelia and discuss comparable mechanisms in mammalian tissues.
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Affiliation(s)
- Yoichiro Tamori
- Structural Biology Center, National Institute of Genetics and Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima 411-8540, Japan.
| | - Wu-Min Deng
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA.
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