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Stammnitz MR, Gori K, Murchison EP. No evidence that a transmissible cancer has shifted from emergence to endemism in Tasmanian devils. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231875. [PMID: 38633353 PMCID: PMC11022658 DOI: 10.1098/rsos.231875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 04/19/2024]
Abstract
Tasmanian devils are endangered by a transmissible cancer known as Tasmanian devil facial tumour 1 (DFT1). A 2020 study by Patton et al. (Science 370, eabb9772 (doi:10.1126/science.abb9772)) used genome data from DFT1 tumours to produce a dated phylogenetic tree for this transmissible cancer lineage, and thence, using phylodynamics models, to estimate its epidemiological parameters and predict its future trajectory. It concluded that the effective reproduction number for DFT1 had declined to a value of one, and that the disease had shifted from emergence to endemism. We show that the study is based on erroneous mutation calls and flawed methodology, and that its conclusions cannot be substantiated.
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Affiliation(s)
- Maximilian R. Stammnitz
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Kevin Gori
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Elizabeth P. Murchison
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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2
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Gallinson DG, Kozakiewicz CP, Rautsaw RM, Beer MA, Ruiz-Aravena M, Comte S, Hamilton DG, Kerlin DH, McCallum HI, Hamede R, Jones ME, Storfer A, McMinds R, Margres MJ. Intergenomic signatures of coevolution between Tasmanian devils and an infectious cancer. Proc Natl Acad Sci U S A 2024; 121:e2307780121. [PMID: 38466855 PMCID: PMC10962979 DOI: 10.1073/pnas.2307780121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 01/17/2024] [Indexed: 03/13/2024] Open
Abstract
Coevolution is common and frequently governs host-pathogen interaction outcomes. Phenotypes underlying these interactions often manifest as the combined products of the genomes of interacting species, yet traditional quantitative trait mapping approaches ignore these intergenomic interactions. Devil facial tumor disease (DFTD), an infectious cancer afflicting Tasmanian devils (Sarcophilus harrisii), has decimated devil populations due to universal host susceptibility and a fatality rate approaching 100%. Here, we used a recently developed joint genome-wide association study (i.e., co-GWAS) approach, 15 y of mark-recapture data, and 960 genomes to identify intergenomic signatures of coevolution between devils and DFTD. Using a traditional GWA approach, we found that both devil and DFTD genomes explained a substantial proportion of variance in how quickly susceptible devils became infected, although genomic architectures differed across devils and DFTD; the devil genome had fewer loci of large effect whereas the DFTD genome had a more polygenic architecture. Using a co-GWA approach, devil-DFTD intergenomic interactions explained ~3× more variation in how quickly susceptible devils became infected than either genome alone, and the top genotype-by-genotype interactions were significantly enriched for cancer genes and signatures of selection. A devil regulatory mutation was associated with differential expression of a candidate cancer gene and showed putative allele matching effects with two DFTD coding sequence variants. Our results highlight the need to account for intergenomic interactions when investigating host-pathogen (co)evolution and emphasize the importance of such interactions when considering devil management strategies.
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Affiliation(s)
- Dylan G. Gallinson
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
- College of Public Health, University of South Florida, Tampa, FL33620
| | - Christopher P. Kozakiewicz
- School of Biological Sciences, Washington State University, Pullman, WA99163
- W.K. Kellogg Biological Station, Department of Integrative Biology, Michigan State University, Hickory Corners, MI49060
| | - Rhett M. Rautsaw
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
- School of Biological Sciences, Washington State University, Pullman, WA99163
| | - Marc A. Beer
- School of Biological Sciences, Washington State University, Pullman, WA99163
| | - Manuel Ruiz-Aravena
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
- Department of Public and Ecosystem Health, Cornell University, Ithaca, NY14853
| | - Sebastien Comte
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
- New South Wales Department of Primary Industries, Vertebrate Pest Research Unit, Orange, NSW2800, Australia
| | - David G. Hamilton
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
| | - Douglas H. Kerlin
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD4111, Australia
| | - Hamish I. McCallum
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD4111, Australia
| | - Rodrigo Hamede
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
- CANECEV Centre de Recherches Ecologiques et Evolutives sur le Cancer, Montpellier34394, France
| | - Menna E. Jones
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
| | - Andrew Storfer
- School of Biological Sciences, Washington State University, Pullman, WA99163
| | - Ryan McMinds
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
- College of Public Health, University of South Florida, Tampa, FL33620
| | - Mark J. Margres
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
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3
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Hart SFM, Yonemitsu MA, Giersch RM, Garrett FES, Beal BF, Arriagada G, Davis BW, Ostrander EA, Goff SP, Metzger MJ. Centuries of genome instability and evolution in soft-shell clam, Mya arenaria, bivalve transmissible neoplasia. NATURE CANCER 2023; 4:1561-1574. [PMID: 37783804 PMCID: PMC10663159 DOI: 10.1038/s43018-023-00643-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 08/29/2023] [Indexed: 10/04/2023]
Abstract
Transmissible cancers are infectious parasitic clones that metastasize to new hosts, living past the death of the founder animal in which the cancer initiated. We investigated the evolutionary history of a cancer lineage that has spread though the soft-shell clam (Mya arenaria) population by assembling a chromosome-scale soft-shell clam reference genome and characterizing somatic mutations in transmissible cancer. We observe high mutation density, widespread copy-number gain, structural rearrangement, loss of heterozygosity, variable telomere lengths, mitochondrial genome expansion and transposable element activity, all indicative of an unstable cancer genome. We also discover a previously unreported mutational signature associated with overexpression of an error-prone polymerase and use this to estimate the lineage to be >200 years old. Our study reveals the ability for an invertebrate cancer lineage to survive for centuries while its genome continues to structurally mutate, likely contributing to the evolution of this lineage as a parasitic cancer.
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Affiliation(s)
- Samuel F M Hart
- Pacific Northwest Research Institute, Seattle, WA, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | - Marisa A Yonemitsu
- Pacific Northwest Research Institute, Seattle, WA, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | | | | | - Brian F Beal
- Division of Environmental and Biological Sciences, University of Maine at Machias, Machias, ME, USA
- Downeast Institute, Beals, ME, USA
| | - Gloria Arriagada
- Instituto de Ciencias Biomedicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- FONDAP Center for Genome Regulation, Santiago, Chile
| | - Brian W Davis
- Department of Veterinary Integrative Biosciences, Texas A&M University School of Veterinary Medicine, College Station, TX, USA
- Department of Small Animal Clinical Sciences, Texas A&M University School of Veterinary Medicine, College Station, TX, USA
| | - Elaine A Ostrander
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Stephen P Goff
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University, New York, NY, USA
| | - Michael J Metzger
- Pacific Northwest Research Institute, Seattle, WA, USA.
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA.
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4
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Hamede R, Fountain‐Jones NM, Arce F, Jones M, Storfer A, Hohenlohe PA, McCallum H, Roche B, Ujvari B, Thomas F. The tumour is in the detail: Local phylogenetic, population and epidemiological dynamics of a transmissible cancer in Tasmanian devils. Evol Appl 2023; 16:1316-1327. [PMID: 37492149 PMCID: PMC10363845 DOI: 10.1111/eva.13569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 06/01/2023] [Accepted: 06/01/2023] [Indexed: 07/27/2023] Open
Abstract
Infectious diseases are a major threat for biodiversity conservation and can exert strong influence on wildlife population dynamics. Understanding the mechanisms driving infection rates and epidemic outcomes requires empirical data on the evolutionary trajectory of pathogens and host selective processes. Phylodynamics is a robust framework to understand the interaction of pathogen evolutionary processes with epidemiological dynamics, providing a powerful tool to evaluate disease control strategies. Tasmanian devils have been threatened by a fatal transmissible cancer, devil facial tumour disease (DFTD), for more than two decades. Here we employ a phylodynamic approach using tumour mitochondrial genomes to assess the role of tumour genetic diversity in epidemiological and population dynamics in a devil population subject to 12 years of intensive monitoring, since the beginning of the epidemic outbreak. DFTD molecular clock estimates of disease introduction mirrored observed estimates in the field, and DFTD genetic diversity was positively correlated with estimates of devil population size. However, prevalence and force of infection were the lowest when devil population size and tumour genetic diversity was the highest. This could be due to either differential virulence or transmissibility in tumour lineages or the development of host defence strategies against infection. Our results support the view that evolutionary processes and epidemiological trade-offs can drive host-pathogen coexistence, even when disease-induced mortality is extremely high. We highlight the importance of integrating pathogen and population evolutionary interactions to better understand long-term epidemic dynamics and evaluating disease control strategies.
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Affiliation(s)
- Rodrigo Hamede
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
- CANECEV, Centre de Recherches Ecologiques et Evolutives sur le CancerMontpellierFrance
| | | | - Fernando Arce
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Menna Jones
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Andrew Storfer
- School of Biological SciencesWashington State UniversityPullmanWashingtonUSA
| | - Paul A. Hohenlohe
- Department of Biological Sciences, Institute for Bioinformatics and Evolutionary StudiesUniversity of IdahoMoscowIdahoUSA
| | - Hamish McCallum
- Centre for Planetary Health and Food SecurityGriffith University, Nathan CampusNathanQueenslandAustralia
| | - Benjamin Roche
- CREEC, MIVEGEC (CREES)University of Montpellier, CNRS, IRDMontpelierFrance
| | - Beata Ujvari
- CANECEV, Centre de Recherches Ecologiques et Evolutives sur le CancerMontpellierFrance
- Centre for Integrative Ecology, School of Life and Environmental SciencesDeakin UniversityWaurn PondsVictoriaAustralia
| | - Frédéric Thomas
- CANECEV, Centre de Recherches Ecologiques et Evolutives sur le CancerMontpellierFrance
- CREEC, MIVEGEC (CREES)University of Montpellier, CNRS, IRDMontpelierFrance
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5
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Stammnitz MR, Gori K, Kwon YM, Harry E, Martin FJ, Billis K, Cheng Y, Baez-Ortega A, Chow W, Comte S, Eggertsson H, Fox S, Hamede R, Jones M, Lazenby B, Peck S, Pye R, Quail MA, Swift K, Wang J, Wood J, Howe K, Stratton MR, Ning Z, Murchison EP. The evolution of two transmissible cancers in Tasmanian devils. Science 2023; 380:283-293. [PMID: 37079675 DOI: 10.1126/science.abq6453] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Tasmanian devils have spawned two transmissible cancer lineages, named devil facial tumor 1 (DFT1) and devil facial tumor 2 (DFT2). We investigated the genetic diversity and evolution of these clones by analyzing 78 DFT1 and 41 DFT2 genomes relative to a newly assembled, chromosome-level reference. Time-resolved phylogenetic trees reveal that DFT1 first emerged in 1986 (1982 to 1989) and DFT2 in 2011 (2009 to 2012). Subclone analysis documents transmission of heterogeneous cell populations. DFT2 has faster mutation rates than DFT1 across all variant classes, including substitutions, indels, rearrangements, transposable element insertions, and copy number alterations, and we identify a hypermutated DFT1 lineage with defective DNA mismatch repair. Several loci show plausible evidence of positive selection in DFT1 or DFT2, including loss of chromosome Y and inactivation of MGA, but none are common to both cancers. This study reveals the parallel long-term evolution of two transmissible cancers inhabiting a common niche in Tasmanian devils.
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Affiliation(s)
- Maximilian R Stammnitz
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Kevin Gori
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Young Mi Kwon
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Edward Harry
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Fergal J Martin
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Konstantinos Billis
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Adrian Baez-Ortega
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - William Chow
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Sebastien Comte
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
- Vertebrate Pest Research Unit, NSW Department of Primary Industries, Orange, NSW, Australia
| | | | - Samantha Fox
- Save the Tasmanian Devil Program, Tasmanian Department of Natural Resources and Environment, Hobart, TAS, Australia
- Toledo Zoo, Toledo, OH, USA
| | - Rodrigo Hamede
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
- CANCEV, Centre de Recherches Ecologiques et Evolutives sur le Cancer, Montpellier, France
| | - Menna Jones
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Billie Lazenby
- Save the Tasmanian Devil Program, Tasmanian Department of Natural Resources and Environment, Hobart, TAS, Australia
| | - Sarah Peck
- Save the Tasmanian Devil Program, Tasmanian Department of Natural Resources and Environment, Hobart, TAS, Australia
| | - Ruth Pye
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Michael A Quail
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Kate Swift
- Mount Pleasant Laboratories, Tasmanian Department of Natural Resources and Environment, Prospect, TAS, Australia
| | - Jinhong Wang
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Jonathan Wood
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Kerstin Howe
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Michael R Stratton
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Zemin Ning
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Elizabeth P Murchison
- Transmissible Cancer Group, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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6
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Dong LF, Rohlena J, Zobalova R, Nahacka Z, Rodriguez AM, Berridge MV, Neuzil J. Mitochondria on the move: Horizontal mitochondrial transfer in disease and health. J Cell Biol 2023; 222:213873. [PMID: 36795453 PMCID: PMC9960264 DOI: 10.1083/jcb.202211044] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/12/2023] [Accepted: 02/01/2023] [Indexed: 02/17/2023] Open
Abstract
Mammalian genes were long thought to be constrained within somatic cells in most cell types. This concept was challenged recently when cellular organelles including mitochondria were shown to move between mammalian cells in culture via cytoplasmic bridges. Recent research in animals indicates transfer of mitochondria in cancer and during lung injury in vivo, with considerable functional consequences. Since these pioneering discoveries, many studies have confirmed horizontal mitochondrial transfer (HMT) in vivo, and its functional characteristics and consequences have been described. Additional support for this phenomenon has come from phylogenetic studies. Apparently, mitochondrial trafficking between cells occurs more frequently than previously thought and contributes to diverse processes including bioenergetic crosstalk and homeostasis, disease treatment and recovery, and development of resistance to cancer therapy. Here we highlight current knowledge of HMT between cells, focusing primarily on in vivo systems, and contend that this process is not only (patho)physiologically relevant, but also can be exploited for the design of novel therapeutic approaches.
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Affiliation(s)
- Lan-Feng Dong
- https://ror.org/02sc3r913School of Pharmacy and Medical Sciences, Griffith University, Southport, Australia,Lan-Feng Dong:
| | - Jakub Rohlena
- https://ror.org/00wzqmx94Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague-West, Czech Republic
| | - Renata Zobalova
- https://ror.org/00wzqmx94Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague-West, Czech Republic
| | - Zuzana Nahacka
- https://ror.org/00wzqmx94Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague-West, Czech Republic
| | | | | | - Jiri Neuzil
- https://ror.org/02sc3r913School of Pharmacy and Medical Sciences, Griffith University, Southport, Australia,https://ror.org/00wzqmx94Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague-West, Czech Republic,Faculty of Science, Charles University, Prague, Czech Republic,First Faculty of Medicine, Charles University, Prague, Czech Republic,Correspondence to Jiri Neuzil: ,
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7
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Ní Leathlobhair M, Lenski RE. Population genetics of clonally transmissible cancers. Nat Ecol Evol 2022; 6:1077-1089. [PMID: 35879542 DOI: 10.1038/s41559-022-01790-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 05/12/2022] [Indexed: 11/08/2022]
Abstract
Populations of cancer cells are subject to the same core evolutionary processes as asexually reproducing, unicellular organisms. Transmissible cancers are particularly striking examples of these processes. These unusual cancers are clonal lineages that can spread through populations via physical transfer of living cancer cells from one host individual to another, and they have achieved long-term success in the colonization of at least eight different host species. Population genetic theory provides a useful framework for understanding the shift from a multicellular sexual animal into a unicellular asexual clone and its long-term effects on the genomes of these cancers. In this Review, we consider recent findings from transmissible cancer research with the goals of developing an evolutionarily informed perspective on transmissible cancers, examining possible implications for their long-term fate and identifying areas for future research on these exceptional lineages.
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Affiliation(s)
- Máire Ní Leathlobhair
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK.
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin, Ireland.
| | - Richard E Lenski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
- Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI, USA
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8
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Capp JP, Thomas F. From developmental to atavistic bet-hedging: How cancer cells pervert the exploitation of random single-cell phenotypic fluctuations. Bioessays 2022; 44:e2200048. [PMID: 35839471 DOI: 10.1002/bies.202200048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 07/05/2022] [Accepted: 07/05/2022] [Indexed: 11/08/2022]
Abstract
Stochastic gene expression plays a leading developmental role through its contribution to cell differentiation. It is also proposed to promote phenotypic diversification in malignant cells. However, it remains unclear if these two forms of cellular bet-hedging are identical or rather display distinct features. Here we argue that bet-hedging phenomena in cancer cells are more similar to those occurring in unicellular organisms than to those of normal metazoan cells. We further propose that the atavistic bet-hedging strategies in cancer originate from a hijacking of the normal developmental bet-hedging of metazoans. Finally, we discuss the constraints that may shape the atavistic bet-hedging strategies of cancer cells.
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Affiliation(s)
- Jean-Pascal Capp
- Toulouse Biotechnology Institute, INSA / University of Toulouse, CNRS, INRAE, Toulouse, France
| | - Frédéric Thomas
- CREEC, UMR IRD 224-CNRS 5290-University of Montpellier, Montpellier, France
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9
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Farquharson KA, McLennan EA, Cheng Y, Alexander L, Fox S, Lee AV, Belov K, Hogg CJ. Restoring faith in conservation action: Maintaining wild genetic diversity through the Tasmanian devil insurance program. iScience 2022; 25:104474. [PMID: 35754729 PMCID: PMC9218385 DOI: 10.1016/j.isci.2022.104474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/06/2022] [Accepted: 05/20/2022] [Indexed: 11/28/2022] Open
Abstract
Conservation breeding programs aim to maintain 90% wild genetic diversity, but rarely assess functional diversity. Here, we compare both genome-wide and functional diversity (in over 500 genes) of Tasmanian devils (Sarcophilus harrisii) within the insurance metapopulation and across the species’ range (64,519 km2). Populations have declined by 80% since 1996 due to a contagious cancer, devil facial tumor disease (DFTD). However, predicted local extinctions have not occurred. Recent suggestions of selection for “resistance” alleles in the wild precipitated concerns that insurance population devils may be unsuitable for translocations. Using 830 wild samples collected at 31 locations between 2012 and 2021, and 553 insurance metapopulation devils, we show that the insurance metapopulation is representative of current wild genetic diversity. Allele frequencies at DFTD-associated loci were not substantially different between captive and wild devils. Methods presented here are valuable for others investigating evolutionary potential in threatened species, particularly ones under significant selective pressures. Developed target capture to assess functional diversity at over 500 genes Fine-scale structure exists in the genetically depauperate Tasmanian devil Insurance metapopulation is representative of wild genetic diversity Allele frequencies at disease-associated loci were similar in captivity to the wild
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Affiliation(s)
| | - Elspeth A McLennan
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Lauren Alexander
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Samantha Fox
- Save the Tasmanian Devil Program, NRE Tasmania, Hobart, Tas 7001, Australia.,Toledo Zoo, 2605 Broadway, Toledo, OH 43609, USA
| | - Andrew V Lee
- Save the Tasmanian Devil Program, NRE Tasmania, Hobart, Tas 7001, Australia.,Toledo Zoo, 2605 Broadway, Toledo, OH 43609, USA
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Carolyn J Hogg
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia.,San Diego Zoo Wildlife Alliance, PO BOX 120551, San Diego, CA 92112, USA
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10
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Dujon AM, Boutry J, Tissot S, Lemaître JF, Boddy AM, Gérard AL, Alvergne A, Arnal A, Vincze O, Nicolas D, Giraudeau M, Telonis-Scott M, Schultz A, Pujol P, Biro PA, Beckmann C, Hamede R, Roche B, Ujvari B, Thomas F. Cancer Susceptibility as a Cost of Reproduction and Contributor to Life History Evolution. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.861103] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Reproduction is one of the most energetically demanding life-history stages. As a result, breeding individuals often experience trade-offs, where energy is diverted away from maintenance (cell repair, immune function) toward reproduction. While it is increasingly acknowledged that oncogenic processes are omnipresent, evolving and opportunistic entities in the bodies of metazoans, the associations among reproductive activities, energy expenditure, and the dynamics of malignant cells have rarely been studied. Here, we review the diverse ways in which age-specific reproductive performance (e.g., reproductive aging patterns) and cancer risks throughout the life course may be linked via trade-offs or other mechanisms, as well as discuss situations where trade-offs may not exist. We argue that the interactions between host–oncogenic processes should play a significant role in life-history theory, and suggest some avenues for future research.
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11
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Hussey K, Caldwell A, Kreiss A, Skjødt K, Gastaldello A, Pye R, Hamede R, Woods GM, Siddle HV. Expression of the Nonclassical MHC Class I, Saha-UD in the Transmissible Cancer Devil Facial Tumour Disease (DFTD). Pathogens 2022; 11:pathogens11030351. [PMID: 35335675 PMCID: PMC8953681 DOI: 10.3390/pathogens11030351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 11/16/2022] Open
Abstract
Devil facial tumour disease (DFTD) is a transmissible cancer that has circulated in the Tasmanian devil population for >25 years. Like other contagious cancers in dogs and devils, the way DFTD escapes the immune response of its host is a central question to understanding this disease. DFTD has a low major histocompatibility complex class I (MHC-I) expression due to epigenetic modifications, preventing host immune recognition of mismatched MHC-I molecules by T cells. However, the total MHC-I loss should result in natural killer (NK) cell activation due to the ‘missing self’. Here, we have investigated the expression of the nonclassical MHC-I, Saha-UD as a potential regulatory or suppressive mechanism for DFTD. A monoclonal antibody was generated against the devil Saha-UD that binds recombinant Saha-UD by Western blot, with limited crossreactivity to the classical MHC-I, Saha-UC and nonclassical Saha-UK. Using this antibody, we confirmed the expression of Saha-UD in 13 DFTD tumours by immunohistochemistry (n = 15) and demonstrated that Saha-UD expression is heterogeneous, with 12 tumours showing intratumour heterogeneity. Immunohistochemical staining for the Saha-UD showed distinct patterns of expression when compared with classical MHC-I molecules. The nonclassical Saha-UD expression by DFTD tumours in vivo may be a mechanism for immunosuppression, and further work is ongoing to characterise its ligand on immune cells.
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Affiliation(s)
- Kathryn Hussey
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; (K.H.); (A.C.); (A.G.)
| | - Alison Caldwell
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; (K.H.); (A.C.); (A.G.)
| | - Alexandre Kreiss
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia; (A.K.); (R.P.); (G.M.W.)
| | - Karsten Skjødt
- Department of Cancer and Inflammation, University of Southern Denmark, 5230 Odense, Denmark;
| | - Annalisa Gastaldello
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; (K.H.); (A.C.); (A.G.)
| | - Ruth Pye
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia; (A.K.); (R.P.); (G.M.W.)
| | - Rodrigo Hamede
- School of Biological Sciences, University of Tasmania, Hobart, TAS 7005, Australia;
| | - Gregory M. Woods
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia; (A.K.); (R.P.); (G.M.W.)
| | - Hannah V. Siddle
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; (K.H.); (A.C.); (A.G.)
- Correspondence:
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12
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Kwon YM, Vranken N, Hoge C, Lichak MR, Norovich AL, Francis KX, Camacho-Garcia J, Bista I, Wood J, McCarthy S, Chow W, Tan HH, Howe K, Bandara S, von Lintig J, Rüber L, Durbin R, Svardal H, Bendesky A. Genomic consequences of domestication of the Siamese fighting fish. SCIENCE ADVANCES 2022; 8:eabm4950. [PMID: 35263139 PMCID: PMC8906746 DOI: 10.1126/sciadv.abm4950] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 01/13/2022] [Indexed: 05/08/2023]
Abstract
Siamese fighting (betta) fish are among the most popular and morphologically diverse pet fish, but the genetic bases of their domestication and phenotypic diversification are largely unknown. We assembled de novo the genome of a wild Betta splendens and whole-genome sequenced 98 individuals across five closely related species. We find evidence of bidirectional hybridization between domesticated ornamental betta and other wild Betta species. We discover dmrt1 as the main sex determination gene in ornamental betta and that it has lower penetrance in wild B. splendens. Furthermore, we find genes with signatures of recent, strong selection that have large effects on color in specific parts of the body or on the shape of individual fins and that most are unlinked. Our results demonstrate how simple genetic architectures paired with anatomical modularity can lead to vast phenotypic diversity generated during animal domestication and launch betta as a powerful new system for evolutionary genetics.
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Affiliation(s)
- Young Mi Kwon
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Nathan Vranken
- Department of Biology, University of Antwerp, 2020 Antwerp, Belgium
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Carla Hoge
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Madison R. Lichak
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | - Amy L. Norovich
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | - Kerel X. Francis
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | | | - Iliana Bista
- Wellcome Sanger Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | | | - Shane McCarthy
- Wellcome Sanger Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | | | - Heok Hui Tan
- Lee Kong Chian Natural History Museum, National University of Singapore, Singapore, Singapore
| | | | - Sepalika Bandara
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Johannes von Lintig
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Lukas Rüber
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern 3012, Switzerland
- Naturhistorisches Museum Bern, Bern 3005, Switzerland
| | - Richard Durbin
- Wellcome Sanger Institute, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Hannes Svardal
- Department of Biology, University of Antwerp, 2020 Antwerp, Belgium
- Naturalis Biodiversity Center, 2333 Leiden, Netherlands
| | - Andres Bendesky
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
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13
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Drawert B, Flies AS, Matthew S, Powell M, Rumsey B. Saving the Devils Is in the Details: Tasmanian Devil Facial Tumor Disease Can Be Eliminated with Interventions. LETTERS IN BIOMATHEMATICS 2022; 9:121-140. [PMID: 37655234 PMCID: PMC10470821 DOI: 10.30707/lib9.1.1681913305.269822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Tasmanian Devils facial tumor disease (DFTD) is severely impacting the population of this wild animal. We developed a computational model of the population of Tasmanian Devils, and the change induced by DFTD. We use this model to test possible intervention strategies Tasmanian conservationists could do. We investigate bait drop vaccination programs, diseased animal removals programs, and evolution of natural immunity. We conclude that a combination of intervention strategies gives the most favorable outcome. An additional goal of this paper is reproducibility of our results. Our StochSS software platform features the ability to share and reproduce the computational notebooks that created all of the results in the paper. We endeavor that all readers should be able to reproduce our results with minimum effort.
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Affiliation(s)
- Brian Drawert
- National Environmental Modeling and Analysis Center, University of North Carolina Asheville, Asheville, NC, USA
| | - Andrew S. Flies
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, 7000, Australia
| | - Sean Matthew
- National Environmental Modeling and Analysis Center, University of North Carolina Asheville, Asheville, NC, USA
| | - Megan Powell
- Department of Mathematics and Statistics, University of North Carolina Asheville, Asheville, NC, USA
| | - Bryan Rumsey
- National Environmental Modeling and Analysis Center, University of North Carolina Asheville, Asheville, NC, USA
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14
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Hammel M, Simon A, Arbiol C, Villalba A, Burioli EAV, Pépin JF, Lamy JB, Benabdelmouna A, Bernard I, Houssin M, Charrière G, Destoumieux-Garzon D, Welch J, Metzger MJ, Bierne N. Prevalence and polymorphism of a mussel transmissible cancer in Europe. Mol Ecol 2022; 31:736-751. [PMID: 34192383 PMCID: PMC8716645 DOI: 10.1111/mec.16052] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/03/2021] [Accepted: 06/21/2021] [Indexed: 02/06/2023]
Abstract
Transmissible cancers are parasitic malignant cell lineages that have acquired the ability to infect new hosts from the same species, or sometimes related species. First described in dogs and Tasmanian devils, transmissible cancers were later discovered in some marine bivalves affected by a leukaemia-like disease. In Mytilus mussels, two lineages of bivalve transmissible neoplasia (BTN) have been described to date (MtrBTN1 and MtrBTN2), both of which emerged in a Mytilus trossulus founder individual. Here, we performed extensive screening of genetic chimerism, a hallmark of transmissible cancer, by genotyping 106 single nucleotide polymorphisms of 5,907 European Mytilus mussels. Genetic analysis allowed us to simultaneously obtain the genotype of hosts - Mytilus edulis, M. galloprovincialis or hybrids - and the genotype of tumours of heavily infected individuals. In addition, a subset of 222 individuals were systematically genotyped and analysed by histology to screen for possible nontransmissible cancers. We detected MtrBTN2 at low prevalence in M. edulis, and also in M. galloprovincialis and hybrids although at a much lower prevalence. No MtrBTN1 or new BTN were found, but eight individuals with nontransmissible neoplasia were observed at a single polluted site on the same sampling date. We observed a diversity of MtrBTN2 genotypes that appeared more introgressed or more ancestral than MtrBTN1 and reference healthy M. trossulus individuals. The observed polymorphism is probably due to somatic null alleles caused by structural variations or point mutations in primer-binding sites leading to enhanced detection of the host alleles. Despite low prevalence, two sublineages divergent by 10% fixed somatic null alleles and one nonsynonymous mtCOI (mitochondrial cytochrome oxidase I) substitution are cospreading in the same geographical area, suggesting a complex diversification of MtrBTN2 since its emergence and host species shift.
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Affiliation(s)
- Maurine Hammel
- ISEM, Univ Montpellier, CNRS, EPHE, IRD, Montpellier,
France,IHPE, Univ Montpellier, CNRS, Ifremer, Univ Perpignan,
Via Domitia, France
| | - Alexis Simon
- ISEM, Univ Montpellier, CNRS, EPHE, IRD, Montpellier,
France
| | | | - Antonio Villalba
- Centro de Investigacións Mariñas,
Consellería do Mar, Xunta de Galicia, Vilanova de Arousa, Spain,Departamento de Ciencias de la Vida, Universidad de
Alcalá, Alcalá de Henares, Spain.,Research Centre for Experimental Marine Biology and
Biotechnology (PIE), University of the Basque Country (UPV/EHU), Plentzia, Basque
Country, Spain
| | - Erika AV Burioli
- IHPE, Univ Montpellier, CNRS, Ifremer, Univ Perpignan,
Via Domitia, France,LABÉO, Caen, France
| | - Jean-François Pépin
- Laboratoire Environnement ressources des Pertuis
Charentais, IFREMER, La Tremblade, France
| | - Jean-Baptiste Lamy
- Santé, Génétique, Microbiologie des
Mollusques, IFREMER, La Tremblade, France
| | | | | | | | | | | | - John Welch
- Department of Genetics, University of Cambridge,
Downing Street, Cambridge, UK
| | | | - Nicolas Bierne
- ISEM, Univ Montpellier, CNRS, EPHE, IRD, Montpellier,
France
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15
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Spatial variation in gene expression of Tasmanian devil facial tumors despite minimal host transcriptomic response to infection. BMC Genomics 2021; 22:698. [PMID: 34579650 PMCID: PMC8477496 DOI: 10.1186/s12864-021-07994-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 09/08/2021] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Transmissible cancers lie at the intersection of oncology and infectious disease, two traditionally divergent fields for which gene expression studies are particularly useful for identifying the molecular basis of phenotypic variation. In oncology, transcriptomics studies, which characterize the expression of thousands of genes, have identified processes leading to heterogeneity in cancer phenotypes and individual prognoses. More generally, transcriptomics studies of infectious diseases characterize interactions between host, pathogen, and environment to better predict population-level outcomes. Tasmanian devils have been impacted dramatically by a transmissible cancer (devil facial tumor disease; DFTD) that has led to widespread population declines. Despite initial predictions of extinction, populations have persisted at low levels, due in part to heterogeneity in host responses, particularly between sexes. However, the processes underlying this variation remain unknown. RESULTS We sequenced transcriptomes from healthy and DFTD-infected devils, as well as DFTD tumors, to characterize host responses to DFTD infection, identify differing host-tumor molecular interactions between sexes, and investigate the extent to which tumor gene expression varies among host populations. We found minimal variation in gene expression of devil lip tissues, either with respect to DFTD infection status or sex. However, 4088 genes were differentially expressed in tumors among our sampling localities. Pathways that were up- or downregulated in DFTD tumors relative to normal tissues exhibited the same patterns of expression with greater intensity in tumors from localities that experienced DFTD for longer. No mRNA sequence variants were associated with expression variation. CONCLUSIONS Expression variation among localities may reflect morphological differences in tumors that alter ratios of normal-to-tumor cells within biopsies. Phenotypic variation in tumors may arise from environmental variation or differences in host immune response that were undetectable in lip biopsies, potentially reflecting variation in host-tumor coevolutionary relationships among sites that differ in the time since DFTD arrival.
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16
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Capp JP, DeGregori J, Nedelcu AM, Dujon AM, Boutry J, Pujol P, Alix-Panabières C, Hamede R, Roche B, Ujvari B, Marusyk A, Gatenby R, Thomas F. Group phenotypic composition in cancer. eLife 2021; 10:63518. [PMID: 33784238 PMCID: PMC8009660 DOI: 10.7554/elife.63518] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 03/09/2021] [Indexed: 12/13/2022] Open
Abstract
Although individual cancer cells are generally considered the Darwinian units of selection in malignant populations, they frequently act as members of groups where fitness of the group cannot be reduced to the average fitness of individual group members. A growing body of studies reveals limitations of reductionist approaches to explaining biological and clinical observations. For example, induction of angiogenesis, inhibition of the immune system, and niche engineering through environmental acidification and/or remodeling of extracellular matrix cannot be achieved by single tumor cells and require collective actions of groups of cells. Success or failure of such group activities depends on the phenotypic makeup of the individual group members. Conversely, these group activities affect the fitness of individual members of the group, ultimately affecting the composition of the group. This phenomenon, where phenotypic makeup of individual group members impacts the fitness of both members and groups, has been captured in the term 'group phenotypic composition' (GPC). We provide examples where considerations of GPC could help in understanding the evolution and clinical progression of cancers and argue that use of the GPC framework can facilitate new insights into cancer biology and assist with the development of new therapeutic strategies.
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Affiliation(s)
- Jean-Pascal Capp
- Toulouse Biotechnology Institute, University of Toulouse, INSA, CNRS, INRAE, Toulouse, France
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Aurora M Nedelcu
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Antoine M Dujon
- CREEC/CANECEV, MIVEGEC (CREES), University of Montpellier, CNRS, IRD, Montpellier, France.,Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Australia
| | - Justine Boutry
- CREEC/CANECEV, MIVEGEC (CREES), University of Montpellier, CNRS, IRD, Montpellier, France
| | - Pascal Pujol
- CREEC/CANECEV, MIVEGEC (CREES), University of Montpellier, CNRS, IRD, Montpellier, France
| | - Catherine Alix-Panabières
- CREEC/CANECEV, MIVEGEC (CREES), University of Montpellier, CNRS, IRD, Montpellier, France.,Laboratory of Rare Human Circulating Cells (LCCRH), University Medical Centre of Montpellier, Montpellier, France
| | - Rodrigo Hamede
- School of Natural Sciences, University of Tasmania, Hobart, Australia
| | - Benjamin Roche
- CREEC/CANECEV, MIVEGEC (CREES), University of Montpellier, CNRS, IRD, Montpellier, France
| | - Beata Ujvari
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Australia.,School of Natural Sciences, University of Tasmania, Hobart, Australia
| | - Andriy Marusyk
- Department of Cancer Physiology, H Lee Moffitt Cancer Center and Research Institute, Tampa, United States
| | - Robert Gatenby
- Department of Cancer Physiology, H Lee Moffitt Cancer Center and Research Institute, Tampa, United States
| | - Frédéric Thomas
- CREEC/CANECEV, MIVEGEC (CREES), University of Montpellier, CNRS, IRD, Montpellier, France
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17
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Pye R, Darby J, Flies AS, Fox S, Carver S, Elmer J, Swift K, Hogg C, Pemberton D, Woods G, Lyons AB. Post-release immune responses of Tasmanian devils vaccinated with an experimental devil facial tumour disease vaccine. WILDLIFE RESEARCH 2021. [DOI: 10.1071/wr20210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Abstract
ContextDisease is increasingly becoming a driver of wildlife population declines and an extinction risk. Vaccines are one of the most successful health interventions in human history, but few have been tested for mitigating wildlife disease. The transmissible cancer, devil facial tumour disease (DFTD), triggered the Tasmanian devil’s (Sarcophilus harrisii) inclusion on the international endangered species list. In 2016, 33 devils from a DFTD-free insurance population were given an experimental DFTD vaccination before their wild release on the Tasmanian northern coast.
AimTo determine the efficacy of the vaccination protocol and the longevity of the induced responses.
MethodSix trapping trips took place over the 2.5 years following release, and both vaccinated and incumbent devils had blood samples and tumour biopsies collected.
Key resultsIn all, 8 of the 33 vaccinated devils were re-trapped, and six of those developed DFTD within the monitoring period. Despite the lack of protection provided by the vaccine, we observed signs of immune activation not usually found in unvaccinated devils. First, sera collected from the eight devils showed that anti-DFTD antibodies persisted for up to 2 years post-vaccination. Second, tumour-infiltrating lymphocytes were found in three of four biopsies collected from vaccinated devils, which contrasts with the ‘immune deserts’ typical of DFTs; only 1 of the 20 incumbent devils with DFTD had a tumour biopsy exhibiting immune-cell infiltrate. Third, immunohistochemical analysis of the vaccinated devils’ tumour biopsies identified the functional immune molecules associated with antigen-presenting cells (MHC-II) and T-cells (CD3), and the immune checkpoint molecule PD-1, all being associated with anti-tumour immunity in other species.
ConclusionsThese results correlate with our previous study on captive devils in which a prophylactic vaccine primed the devil immune system and, following DFTD challenge and tumour growth, immunotherapy induced complete tumour regressions. The field trial results presented here provide further evidence that the devil immune system can be primed to recognise DFTD cells, but additional immune manipulation could be needed for complete protection or induction of tumour regressions.
ImplicationsA protective DFTD vaccine would provide a valuable management approach for conservation of the Tasmanian devil.
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