1
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Marongiu F, Cheri S, Laconi E. Clones of aging: When better fitness can be dangerous. Eur J Cell Biol 2023; 102:151340. [PMID: 37423036 DOI: 10.1016/j.ejcb.2023.151340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/29/2023] [Accepted: 07/05/2023] [Indexed: 07/11/2023] Open
Abstract
The biological and clinical significance of aberrant clonal expansions in aged tissues is being intensely discussed. Evidence is accruing that these clones often result from the normal dynamics of cell turnover in our tissues. The aged tissue microenvironment is prone to favour the emergence of specific clones with higher fitness partly because of an overall decline in cell intrinsic regenerative potential of surrounding counterparts. Thus, expanding clones in aged tissues need not to be mechanistically associated with the development of cancer, albeit this is a possibility. We suggest that growth pattern is a critical phenotypic attribute that impacts on the fate of such clonal proliferations. The acquisition of a better proliferative fitness, coupled with a defect in tissue pattern formation, could represent a dangerous mix setting the stage for their evolution towards neoplasia.
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Affiliation(s)
- Fabio Marongiu
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Samuele Cheri
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Ezio Laconi
- Department of Biomedical Sciences, University of Cagliari, Italy.
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2
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Somatic variation in normal tissues: friend or foe of cancer early detection? Ann Oncol 2022; 33:1239-1249. [PMID: 36162751 DOI: 10.1016/j.annonc.2022.09.156] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/03/2022] [Accepted: 09/10/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Seemingly normal tissues progressively become populated by mutant clones over time. Most of these clones bear mutations in well-known cancer genes but only rarely do they transform into cancer. This poses questions on what triggers cancer initiation and what implications somatic variation has for cancer early detection. DESIGN We analysed recent mutational screens of healthy and cancer-free diseased tissues to compare somatic drivers and the causes of somatic variation across tissues. We then reviewed the mechanisms of clonal expansion and their relationships with age and diseases other than cancer. We finally discussed the relevance of somatic variation for cancer initiation and how it can help or hinder cancer detection and prevention. RESULTS The extent of somatic variation is highly variable across tissues and depends on intrinsic features, such as tissue architecture and turnover, as well as the exposure to endogenous and exogenous insults. Most somatic mutations driving clonal expansion are tissue-specific and inactivate tumor suppressor genes involved in chromatin modification and cell growth signaling. Some of these genes are more frequently mutated in normal tissues than cancer, indicating a context-dependent cancer promoting or protective role. Mutant clones can persist over a long time or disappear rapidly, suggesting that their fitness depends on the dynamic equilibrium with the environment. The disruption of this equilibrium is likely responsible for their transformation into malignant clones and knowing what triggers this process is key for cancer prevention and early detection. Somatic variation should be considered in liquid biopsy, where it may contribute cancer-independent mutations, and in the identification of cancer drivers, since not all mutated genes favoring clonal expansion also drive tumorigenesis. CONCLUSIONS Somatic variation and the factors governing homeostasis of normal tissues should be taken into account when devising strategies for cancer prevention and early detection.
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3
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Rahal Z, Sinjab A, Wistuba II, Kadara H. Game of clones: Battles in the field of carcinogenesis. Pharmacol Ther 2022; 237:108251. [PMID: 35850404 PMCID: PMC10249058 DOI: 10.1016/j.pharmthera.2022.108251] [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: 03/01/2022] [Revised: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 11/22/2022]
Abstract
Recent advances in bulk sequencing approaches as well as genomic decoding at the single-cell level have revealed surprisingly high somatic mutational burdens in normal tissues, as well as increased our understanding of the landscape of "field cancerization", that is, molecular and immune alterations in mutagen-exposed normal-appearing tissues that recapitulated those present in tumors. Charting the somatic mutational landscapes in normal tissues can have strong implications on our understanding of how tumors arise from mutagenized epithelium. Making sense of those mutations to understand the progression along the pathologic continuum of normal epithelia, preneoplasias, up to malignant tissues will help pave way for identification of ideal targets that can guide new strategies for preventing or eliminating cancers at their earliest stages of development. In this review, we will provide a brief history of field cancerization and its implications on understanding early stages of cancer pathogenesis and deviation from the pathologically "normal" state. The review will provide an overview of how mutations accumulating in normal tissues can lead to a patchwork of mutated cell clones that compete while maintaining an overall state of functional homeostasis. The review also explores the role of clonal competition in directing the fate of normal tissues and summarizes multiple mechanisms elicited in this phenomenon and which have been linked to cancer development. Finally, we highlight the importance of understanding mutations in normal tissues, as well as clonal competition dynamics (in both the epithelium and the microenvironment) and their significance in exploring new approaches to combatting cancer.
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Affiliation(s)
- Zahraa Rahal
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, USA
| | - Ansam Sinjab
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, USA
| | - Ignacio I Wistuba
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, USA
| | - Humam Kadara
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, USA.
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4
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Marongiu F, DeGregori J. The sculpting of somatic mutational landscapes by evolutionary forces and their impacts on aging-related disease. Mol Oncol 2022; 16:3238-3258. [PMID: 35726685 PMCID: PMC9490148 DOI: 10.1002/1878-0261.13275] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/29/2022] [Accepted: 05/19/2022] [Indexed: 12/19/2022] Open
Abstract
Aging represents the major risk factor for the development of cancer and many other diseases. Recent findings show that normal tissues become riddled with expanded clones that are frequently driven by cancer‐associated mutations in an aging‐dependent fashion. Additional studies show how aged tissue microenvironments promote the initiation and progression of malignancies, while young healthy tissues actively suppress the outgrowth of malignant clones. Here, we discuss conserved mechanisms that eliminate poorly functioning or potentially malignant cells from our tissues to maintain organismal health and fitness. Natural selection acts to preserve tissue function and prevent disease to maximize reproductive success but these mechanisms wane as reproduction becomes less likely. The ensuing age‐dependent tissue decline can impact the shape and direction of clonal somatic evolution, with lifestyle and exposures influencing its pace and intensity. We also consider how aging‐ and exposure‐dependent clonal expansions of “oncogenic” mutations might both increase cancer risk late in life and contribute to tissue decline and non‐malignant disease. Still, we can marvel at the ability of our bodies to avoid cancers and other diseases despite the accumulation of billions of cells with cancer‐associated mutations.
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Affiliation(s)
- Fabio Marongiu
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.,Department of Biomedical Sciences, Section of Pathology, University of Cagliari, Italy
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.,University of Colorado Comprehensive Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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5
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Marongiu F, Cheri S, Laconi E. Cell competition, cooperation, and cancer. Neoplasia 2021; 23:1029-1036. [PMID: 34500336 PMCID: PMC8429595 DOI: 10.1016/j.neo.2021.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/26/2021] [Accepted: 08/11/2021] [Indexed: 12/29/2022]
Abstract
Complex multicellular organisms require quantitative and qualitative assessments on each of their constitutive cell types to ensure coordinated and cooperative behavior towards overall functional proficiency. Cell competition represents one of the operating arms of such quality control mechanisms and relies on fitness comparison among individual cells. However, what is exactly included in the fitness equation for each cell type is still uncertain. Evidence will be discussed to suggest that the ability of the cell to integrate and collaborate within the organismal community represents an integral part of the best fitness phenotype. Thus, under normal conditions, cell competition will select against the emergence of altered cells with disruptive behavior towards tissue integrity and/or tissue pattern formation. On the other hand, the winner phenotype prevailing as a result of cell competition does not entail, by itself, any degree of growth autonomy. While cell competition per se should not be considered as a biological driving force towards the emergence of the neoplastic phenotype, it is possible that the molecular machinery involved in the winner/loser interaction could be hijacked by evolving cancer cell populations.
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Affiliation(s)
- Fabio Marongiu
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Samuele Cheri
- Department of Biomedical Sciences, University of Cagliari, Italy
| | - Ezio Laconi
- Department of Biomedical Sciences, University of Cagliari, Italy.
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6
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Evans EJ, DeGregori J. Cells with Cancer-associated Mutations Overtake Our Tissues as We Age. AGING AND CANCER 2021; 2:82-97. [PMID: 34888527 PMCID: PMC8651076 DOI: 10.1002/aac2.12037] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/02/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND To shed light on the earliest events in oncogenesis, there is growing interest in understanding the mutational landscapes of normal tissues across ages. In the last decade, next-generation sequencing of human tissues has revealed a surprising abundance of cells with what would be considered oncogenic mutations. AIMS We performed meta-analysis on previously published sequencing data on normal tissues to categorize mutations based on their presence in cancer and showcase the quantity of cells with cancer-associated mutations in cancer-free individuals. METHODS AND RESULTS We analyzed sequencing data from these studies of normal tissues to determine the prevalence of cells with mutations in three different categories across multiple age groups: 1) mutations in genes designated as drivers, 2) mutations that are in the Cancer Gene Census (CGC), and 3) mutations in the CGC that are considered pathogenic. As we age, the percentage of cells in all three levels increase significantly, reaching over 50% of cells having oncogenic mutations for multiple tissues in the older age groups. The clear enrichment for these mutations, particularly at older ages, likely indicates strong selection for the resulting phenotypes. Combined with an estimation of the number of cells in tissues, we calculate that most older, cancer-free individuals possess at least a 100 billion cells that harbor at least one oncogenic mutation, presumably emanating from a fitness advantage conferred by these mutations that promotes clonal expansion. CONCLUSIONS These studies of normal tissues have highlighted the specific drivers of clonal expansion and how frequently they appear in us. Their high prevalence throughout cancer-free individuals necessitates reconsideration of the oncogenicity of these mutations, which could shape methods of detection, prevention and treatment of cancer, as well as of the potential impact of these mutations on tissue function and our health.
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Affiliation(s)
- Edward J. Evans
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- University of Colorado Comprehensive Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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7
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Cooks T, Puzis R, Cohen O. Tissue resilience: lessons from social resilience: Social sciences research on community resilience could inspire biology to understand homeostasis. EMBO Rep 2021; 22:e52926. [PMID: 34288363 DOI: 10.15252/embr.202152926] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/06/2021] [Indexed: 12/25/2022] Open
Abstract
Molecular biology could find inspiration from social sciences and ecology research on how communities remain resilient in times of crisis to better understand tissue homeostasis and resilience.
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Affiliation(s)
- Tomer Cooks
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Rami Puzis
- Software and Information System Engineering Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Odeya Cohen
- Nursing Department, Recanati School for Community Health Professions, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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8
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Marques-Reis M, Moreno E. Role of cell competition in ageing. Dev Biol 2021; 476:79-87. [PMID: 33753080 DOI: 10.1016/j.ydbio.2021.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/25/2021] [Accepted: 03/16/2021] [Indexed: 11/30/2022]
Abstract
Recent advances in rapid medical detection and diagnostic technology have extended both human health and life expectancy. However, ageing remains one of the critical risk factors in contributing to major incapacitating and fatal conditions, including cancer and neurodegeneration. Therefore, it is vital to study how ageing attributes to (or participates in) endangering human health via infliction of age-related diseases and what must be done to tackle this intractable process. This review encompasses the most recent literature elaborating the role of cell competition (CC) during ageing. CC is a process that occurs between two heterogeneous populations, where the cells with higher fitness levels have a competitive advantage over the neighbouring cells that have comparatively lower fitness levels. This interaction results in the selection of the fit cells, within a population, and elimination of the viable yet suboptimal cells. Therefore, it is tempting to speculate that, if this quality control mechanism works efficiently throughout life, can it ultimately lead to a healthier ageing and extended lifespan. Furthermore, the review aims to collate all the important state of the art publications that provides evidence of the relevance of CC in dietary restriction, stem cell dynamics, and cell senescence, thus, prompting us to advocate its contribution and in exploring new avenues and opportunities in fighting age-related conditions.
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Affiliation(s)
- Mariana Marques-Reis
- Cell Fitness Laboratory, Champalimaud Centre for the Unknown, Av. Brasília, 1400-038, Lisbon, Portugal
| | - Eduardo Moreno
- Cell Fitness Laboratory, Champalimaud Centre for the Unknown, Av. Brasília, 1400-038, Lisbon, Portugal.
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9
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Stadler T, Pybus OG, Stumpf MPH. Phylodynamics for cell biologists. Science 2021; 371:371/6526/eaah6266. [PMID: 33446527 DOI: 10.1126/science.aah6266] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
Abstract
Multicellular organisms are composed of cells connected by ancestry and descent from progenitor cells. The dynamics of cell birth, death, and inheritance within an organism give rise to the fundamental processes of development, differentiation, and cancer. Technical advances in molecular biology now allow us to study cellular composition, ancestry, and evolution at the resolution of individual cells within an organism or tissue. Here, we take a phylogenetic and phylodynamic approach to single-cell biology. We explain how "tree thinking" is important to the interpretation of the growing body of cell-level data and how ecological null models can benefit statistical hypothesis testing. Experimental progress in cell biology should be accompanied by theoretical developments if we are to exploit fully the dynamical information in single-cell data.
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Affiliation(s)
- T Stadler
- Department of Biosystems Science and Engineering, ETH Zürich, Switzerland. .,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - O G Pybus
- Department of Zoology, University of Oxford, Oxford, UK.
| | - M P H Stumpf
- Melbourne Integrative Genomics, School of BioSciences and School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia.
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10
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Aiderus A, Contreras-Sandoval AM, Meshey AL, Newberg JY, Ward JM, Swing DA, Copeland NG, Jenkins NA, Mann KM, Mann MB. Promoterless Transposon Mutagenesis Drives Solid Cancers via Tumor Suppressor Inactivation. Cancers (Basel) 2021; 13:E225. [PMID: 33435458 PMCID: PMC7827284 DOI: 10.3390/cancers13020225] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 12/19/2022] Open
Abstract
A central challenge in cancer genomics is the systematic identification of single and cooperating tumor suppressor gene mutations driving cellular transformation and tumor progression in the absence of oncogenic driver mutation(s). Multiple in vitro and in vivo gene inactivation screens have enhanced our understanding of the tumor suppressor gene landscape in various cancers. However, these studies are limited to single or combination gene effects, specific organs, or require sensitizing mutations. In this study, we developed and utilized a Sleeping Beauty transposon mutagenesis system that functions only as a gene trap to exclusively inactivate tumor suppressor genes. Using whole body transposon mobilization in wild type mice, we observed that cumulative gene inactivation can drive tumorigenesis of solid cancers. We provide a quantitative landscape of the tumor suppressor genes inactivated in these cancers and show that, despite the absence of oncogenic drivers, these genes converge on key biological pathways and processes associated with cancer hallmarks.
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Affiliation(s)
- Aziz Aiderus
- Department of Molecular Oncology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (A.A.); (A.M.C.-S.); (A.L.M.); (J.Y.N.)
| | - Ana M. Contreras-Sandoval
- Department of Molecular Oncology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (A.A.); (A.M.C.-S.); (A.L.M.); (J.Y.N.)
| | - Amanda L. Meshey
- Department of Molecular Oncology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (A.A.); (A.M.C.-S.); (A.L.M.); (J.Y.N.)
| | - Justin Y. Newberg
- Department of Molecular Oncology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (A.A.); (A.M.C.-S.); (A.L.M.); (J.Y.N.)
- Cancer Research Program, Houston Methodist Research Institute, Houston, TX 77030, USA; (N.G.C.); (N.A.J.)
| | - Jerrold M. Ward
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore;
| | - Deborah A. Swing
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA;
| | - Neal G. Copeland
- Cancer Research Program, Houston Methodist Research Institute, Houston, TX 77030, USA; (N.G.C.); (N.A.J.)
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore;
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA;
| | - Nancy A. Jenkins
- Cancer Research Program, Houston Methodist Research Institute, Houston, TX 77030, USA; (N.G.C.); (N.A.J.)
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore;
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA;
| | - Karen M. Mann
- Department of Molecular Oncology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (A.A.); (A.M.C.-S.); (A.L.M.); (J.Y.N.)
- Cancer Research Program, Houston Methodist Research Institute, Houston, TX 77030, USA; (N.G.C.); (N.A.J.)
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore;
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA;
- Departments of Gastrointestinal Oncology & Malignant Hematology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Cancer Biology and Evolution Program, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Department of Oncologic Sciences, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Michael B. Mann
- Department of Molecular Oncology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (A.A.); (A.M.C.-S.); (A.L.M.); (J.Y.N.)
- Cancer Research Program, Houston Methodist Research Institute, Houston, TX 77030, USA; (N.G.C.); (N.A.J.)
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore;
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA;
- Cancer Biology and Evolution Program, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Department of Oncologic Sciences, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
- Donald A. Adam Melanoma and Skin Cancer Research Center of Excellence, Moffitt Cancer Center, Tampa, FL 33612, USA
- Department of Cutaneous Oncology, Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
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11
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Sandoval M, Ying Z, Beronja S. Interplay of opposing fate choices stalls oncogenic growth in murine skin epithelium. eLife 2021; 10:54618. [PMID: 33393458 PMCID: PMC7817173 DOI: 10.7554/elife.54618] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 12/31/2020] [Indexed: 12/18/2022] Open
Abstract
Skin epithelium can accumulate a high burden of oncogenic mutations without morphological or functional consequences. To investigate the mechanism of oncogenic tolerance, we induced HrasG12V in single murine epidermal cells and followed them long term. We observed that HrasG12V promotes an early and transient clonal expansion driven by increased progenitor renewal that is replaced with an increase in progenitor differentiation leading to reduced growth. We attribute this dynamic effect to emergence of two populations within oncogenic clones: renewing progenitors along the edge and differentiating ones within the central core. As clone expansion is accompanied by progressive enlargement of the core and diminishment of the edge compartment, the intraclonal competition between the two populations results in stabilized oncogenic growth. To identify the molecular mechanism of HrasG12V-driven differentiation, we screened known Ras-effector in vivo and identified Rassf5 as a novel regulator of progenitor fate choice that is necessary and sufficient for oncogene-specific differentiation.
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Affiliation(s)
- Madeline Sandoval
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, United States
| | - Zhe Ying
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Slobodan Beronja
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, United States
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12
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Fiala C, Diamandis EP. Mutations in normal tissues-some diagnostic and clinical implications. BMC Med 2020; 18:283. [PMID: 33115454 PMCID: PMC7594459 DOI: 10.1186/s12916-020-01763-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 08/25/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND It has long been known that mutations are at the core of many diseases, most notably cancer. Mutational analysis of tissues and fluids is useful for cancer and other disease diagnosis and management. MAIN BODY The prevailing cancer development hypothesis posits that cancer originates from mutations in cancer-driving genes that accumulate in tissues over time. These mutations then confer special characteristics to cancer cells, known as the hallmarks of cancer. Mutations in specific driver genes can lead to the formation of cancerous subclones and mutation risk increases with age. New research has revealed an unexpectedly large number of mutations in normal tissues; these findings could have significant implications to the understanding of the pathobiology of cancer and for disease diagnosis and therapy. Here, we discuss how the prevalence of mutations in normal tissues provides novel and relevant insights about clonal development in cancer and other diseases. Specifically, this review will focus on discussing mutations in normal tissues in the context of developing specific, circulating tumor DNA (ctDNA) tests for cancer, and evaluating clonal hematopoiesis as a predictor of blood cancers and cardiovascular pathology, as well as their implications to the phenomena of neural mosaicism in the context of Alzheimer's disease. CONCLUSIONS In view of these new findings, the fundamental differences between the accumulation of genetic alterations in healthy, aging tissues compared to cancer and cardiovascular or neural diseases will need to be better delineated in the future.
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Affiliation(s)
- Clare Fiala
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
| | - Eleftherios P Diamandis
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada.
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
- Department of Clinical Biochemistry, Mount Sinai Hospital and University Health Network, 60 Murray St. Box 32, Floor 6, Rm L6-201, Toronto, ON, MST 3L9, Canada.
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13
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Piedrafita G, Fernández LC, Real FX. Mutations in Non-Tumoral Human Urothelium: Disease Prelude or Epilogue? Bladder Cancer 2020. [DOI: 10.3233/blc-200363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Bladder cancer is characterized by high rates of recurrence and multifocality, features which have commonly been associated with the colonization of widespread areas of non-neoplastic urothelium by mutant cells, a phenomenon known as field change. Whether mutant fields in the bladder arise from tumor cells or develop from the accumulation of somatic mutations followed by clonal expansions of non-transformed progenitor cells during lifetime remains unanswered. In this issue, Strandgaard et al. perform a deep-sequencing analysis of paired samples of tumor and histologically normal-appearing urothelium from four patients with advanced bladder cancer. By using a careful validation process, they report several mutations exclusive of normal, non-neoplastic tissue, suggesting that multiple fields precede (or develop independently from) the disease. Here, we discuss the main results from this work and elaborate on the biological implications and open questions in the context of normal somatic clonal evolution and cancer risk. We finish providing some general guidelines for future experiments to resolve the role of field changes in bladder carcinogenesis and its possible clinical relevance.
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Affiliation(s)
- Gabriel Piedrafita
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- Department of Biochemistry and Molecular Biology, Complutense University, Madrid, Spain
| | - Luis C. Fernández
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- Faculty of Biomedical Sciences and Health, Universidad Europea de Madrid, Madrid, Spain
| | - Francisco X. Real
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- CIBERONC, Madrid, Spain
- Departament de Ciéncies Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
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14
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Laconi E, Marongiu F, DeGregori J. Cancer as a disease of old age: changing mutational and microenvironmental landscapes. Br J Cancer 2020; 122:943-952. [PMID: 32042067 PMCID: PMC7109142 DOI: 10.1038/s41416-019-0721-1] [Citation(s) in RCA: 141] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 12/09/2019] [Accepted: 12/19/2019] [Indexed: 01/27/2023] Open
Abstract
Why do we get cancer mostly when we are old? According to current paradigms, the answer is simple: mutations accumulate in our tissues throughout life, and some of these mutations contribute to cancers. Although mutations are necessary for cancer development, a number of studies shed light on roles for ageing and exposure-dependent changes in tissue landscapes that determine the impact of oncogenic mutations on cellular fitness, placing carcinogenesis into an evolutionary framework. Natural selection has invested in somatic maintenance to maximise reproductive success. Tissue maintenance not only ensures functional robustness but also prevents the occurrence of cancer through periods of likely reproduction by limiting selection for oncogenic events in our cells. Indeed, studies in organisms ranging from flies to humans are revealing conserved mechanisms to eliminate damaged or oncogenically initiated cells from tissues. Reports of the existence of striking numbers of oncogenically initiated clones in normal tissues and of how this clonal architecture changes with age or external exposure to noxious substances provide critical insight into the early stages of cancer development. A major challenge for cancer biology will be the integration of these studies with epidemiology data into an evolutionary theory of carcinogenesis, which could have a large impact on addressing cancer risk and treatment.
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Affiliation(s)
- Ezio Laconi
- Department of Biomedical Sciences, Section of Pathology, University of Cagliari School of Medicine, 09126, Cagliari, Italy.
| | - Fabio Marongiu
- Department of Biomedical Sciences, Section of Pathology, University of Cagliari School of Medicine, 09126, Cagliari, Italy
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, Integrated Department of Immunology, Department of Pediatrics, Department of Medicine (Section of Hematology), University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
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15
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Bowling S, Lawlor K, Rodríguez TA. Cell competition: the winners and losers of fitness selection. Development 2019; 146:146/13/dev167486. [PMID: 31278123 DOI: 10.1242/dev.167486] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The process of cell competition results in the 'elimination of cells that are viable but less fit than surrounding cells'. Given the highly heterogeneous nature of our tissues, it seems increasingly likely that cells are engaged in a 'survival of the fittest' battle throughout life. The process has a myriad of positive roles in the organism: it selects against mutant cells in developing tissues, prevents the propagation of oncogenic cells and eliminates damaged cells during ageing. However, 'super-fit' cancer cells can exploit cell competition mechanisms to expand and spread. Here, we review the regulation, roles and risks of cell competition in organism development, ageing and disease.
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Affiliation(s)
- Sarah Bowling
- National Heart and Lung Institute, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Katerina Lawlor
- National Heart and Lung Institute, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Tristan A Rodríguez
- National Heart and Lung Institute, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
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16
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Higa KC, DeGregori J. Decoy fitness peaks, tumor suppression, and aging. Aging Cell 2019; 18:e12938. [PMID: 30848555 PMCID: PMC6516171 DOI: 10.1111/acel.12938] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 02/05/2019] [Indexed: 12/24/2022] Open
Abstract
Recent reports by Martincorena et al and Yokoyama et al reveal unanticipated dynamics of somatic evolution in the esophageal epithelium, with clonal expansions apparently driven by mutations in Notch1 dominating the epithelium even in middle-aged individuals, far outpacing the prevalence of these mutations in esophageal cancers. We propose a model whereby the promotion of clonal expansions by mutations such as in Notch1 can limit more malignant somatic evolutionary trajectories until old ages.
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Affiliation(s)
- Kelly C. Higa
- Department of Biochemistry and Molecular GeneticsUniversity of Colorado School of MedicineAuroraColorado
- Integrated Department of ImmunologyUniversity of Colorado School of MedicineAuroraColorado
| | - James DeGregori
- Department of Biochemistry and Molecular GeneticsUniversity of Colorado School of MedicineAuroraColorado
- Integrated Department of ImmunologyUniversity of Colorado School of MedicineAuroraColorado
- Department of PediatricsUniversity of Colorado School of MedicineAuroraColorado
- Department of Medicine, Section of HematologyUniversity of Colorado School of MedicineAuroraColorado
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