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Greenspan LJ, Matunis EL. Retinoblastoma Intrinsically Regulates Niche Cell Quiescence, Identity, and Niche Number in the Adult Drosophila Testis. Cell Rep 2019; 24:3466-3476.e8. [PMID: 30257208 PMCID: PMC6226258 DOI: 10.1016/j.celrep.2018.08.083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/29/2018] [Accepted: 08/27/2018] [Indexed: 12/20/2022] Open
Abstract
Homeostasis in adult tissues depends on the precise regulation of stem cells and their surrounding microenvironments, or niches. Here, we show that the cell cycle inhibitor and tumor suppressor Retinoblastoma (RB) is a critical regulator of niche cells in the Drosophila testis. The testis contains a single niche, composed of somatic hub cells, that signals to adjacent germline and somatic stem cells. Hub cells are normally quiescent, but knockdown of the RB homolog Rbf in these cells causes them to proliferate and convert to somatic stem cells. Over time, mutant hub cell clusters enlarge and split apart, forming ectopic hubs surrounded by active stem cells. Furthermore, we show that Rbf’s ability to restrict niche number depends on the transcription factors E2F and Escargot and the adhesion molecule E-cadherin. Together this work reveals how precise modulation of niche cells, not only the stem cells they support, can drive regeneration and disease. Greenspan and Matunis find that the tumor suppressor Retinoblastoma is required in niche cells to maintain quiescence, cell fate, and niche number. Loss of Retinoblastoma causes niche cell divisions, conversion to somatic stem cells, and ectopic niche formation through niche fission, suggesting that mutations in niche cells may drive disease.
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Affiliation(s)
- Leah J Greenspan
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Erika L Matunis
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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2
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Kohoutova D, Pejchal J, Bures J. Mitotic and apoptotic activity in colorectal neoplasia. BMC Gastroenterol 2018; 18:65. [PMID: 29776402 PMCID: PMC5960157 DOI: 10.1186/s12876-018-0786-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 04/24/2018] [Indexed: 12/20/2022] Open
Abstract
Background Colorectal cancer (CRC) is third most commonly diagnosed cancer worldwide. The aim of the prospective study was to evaluate mitosis and apoptosis of epithelial cells at each stage of colorectal neoplasia. Methods A total of 61 persons were enrolled into the study: 18 patients with non-advanced colorectal adenoma (non-a-A), 13 patients with advanced colorectal adenoma (a-A), 13 patients with CRC and 17 controls: individuals with normal findings on colonoscopy. Biopsy samples were taken from pathology (patients) and healthy mucosa (patients and healthy controls). Samples were formalin-fixed paraffin-embedded and stained with haematoxylin-eosin. Mitotic and apoptotic activity were evaluated in lower and upper part of the crypts and in the superficial compartment. Apoptotic activity was also assessed using detection of activated caspase-3. Results In controls, mitotic activity was present in lower part of crypts, accompanied with low apoptotic activity. Mitotic and apoptotic activity decreased (to almost zero) in upper part of crypts. In superficial compartment, increase in apoptotic activity was observed. Transformation of healthy mucosa into non-a-A was associated with significant increase of mitotic activity in lower and upper part of the crypts and with significant increase of apoptotic activity in all three compartments; p < 0.05. Transformation of non-a-A into a-A did not lead to any further significant increase in apoptotic activity, but was related to significant increase in mitotic activity in upper part of crypts and superficial compartment. A significant decrease in apoptotic activity was detected in all three comparments of CRC samples compared to a-A; p < 0.05. No differences in mitotic and apoptotic activity between biopsies in healthy controls and biopsy samples from healthy mucosa in patients with colorectal neoplasia were observed. Detection of activated caspase-3 confirmed the above findings in apoptotic activity. Conclusions Significant dysregulation of mitosis and apoptosis during the progression of colorectal neoplasia, corresponding with histology, was confirmed. In patients with sporadic colorectal neoplasia, healthy mucosa does not display different mitotic and apoptotic activity compared to mucosa in healthy controls and therefore adequate endoscopic/surgical removal of colorectal neoplasia is sufficient.
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Affiliation(s)
- Darina Kohoutova
- Charles University, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove, 2nd Department of Internal Medicine - Gastroenterology, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.
| | - Jaroslav Pejchal
- University of Defence, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic
| | - Jan Bures
- Charles University, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove, 2nd Department of Internal Medicine - Gastroenterology, Sokolska 581, 500 05, Hradec Kralove, Czech Republic
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3
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Abstract
The process of crypt formation and the roles of Wnt and cell-cell adhesion signaling in cryptogenesis are not well described; but are important to the understanding of both normal and cancer colon crypt biology. A quantitative 3D-microscopy and image analysis technique is used to study the frequency, morphology and molecular topography associated with crypt formation. Measurements along the colon reveal the details of crypt formation and some key underlying biochemical signals regulating normal colon biology. Our measurements revealed an asymmetrical crypt budding process, contrary to the previously reported symmetrical fission of crypts. 3D immunofluorescence analyses reveals heterogeneity in the subcellular distribution of E-cadherin and β-catenin in distinct crypt populations. This heterogeneity was also found in asymmetrical budding crypts. Singular crypt formation (i.e. no multiple new crypts forming from one parent crypt) were observed in crypts isolated from the normal colon mucosa, suggestive of a singular constraint mechanism to prevent aberrant crypt production. The technique presented improves our understanding of cryptogenesis and suggests that excess colon crypt formation occurs when Wnt signaling is perturbed (e.g. by truncation of adenomatous polyposis coli, APC protein) in most colon cancers.
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Abstract
Adult animals rely on populations of stem cells to ensure organ function throughout their lifetime. Stem cells are governed by signals from stem cell niches, and much is known about how single niches promote stemness and direct stem cell behavior. However, most organs contain a multitude of stem cell-niche units, which are often distributed across the entire expanse of the tissue. Beyond the biology of individual stem cell-niche interactions, the next challenge is to uncover the tissue-level processes that orchestrate spatial control of stem-based renewal, repair, and remodeling throughout a whole organ. Here we examine what is known about higher order mechanisms for interniche coordination in epithelial organs, whose simple geometry offers a promising entry point for understanding the regulation of niche number, distribution, and activity. We also consider the potential existence of stem cell territories and how tissue architecture may influence niche coordination.
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Affiliation(s)
- Lucy Erin O'Brien
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305;
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Latifah SY, Armania N, Tze TH, Azhar Y, Nordiana AH, Norazalina S, Hairuszah I, Saidi M, Maznah I. Germinated brown rice (GBR) reduces the incidence of aberrant crypt foci with the involvement of beta-catenin and COX-2 in azoxymethane-induced colon cancer in rats. Nutr J 2010; 9:16. [PMID: 20346115 PMCID: PMC2868780 DOI: 10.1186/1475-2891-9-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 03/26/2010] [Indexed: 01/31/2023] Open
Abstract
Chemoprevention has become an important area in cancer research due to the failure of current therapeutic modalities. Epidemiological and preclinical studies have demonstrated that nutrition plays a vital role in the etiology of cancer. This study was conducted to determine the chemopreventive effects of germinated brown rice (GBR) in rats induced with colon cancer. GBR is brown rice that has been claimed to be richer in nutrients compared to the common white rice. The male Sprague Dawley rats (6 weeks of age) were randomly divided into 5 groups: (G1) positive control (with colon cancer, unfed with GBR), (G2) fed with 2.5 g/kg of GBR (GBR (g)/weight of rat (kg)), (G3) fed with 5 g/kg of GBR, (G4) fed with 10 g/kg of GBR and (G5) negative control (without colon cancer, unfed with GBR). GBR was administered orally once daily via gavage after injection of 15 mg/kg of body weight of azoxymethane (AOM) once a week for two weeks, intraperitonially. After 8 weeks of treatment, animals were sacrificed and colons were removed. Colonic aberrant crypt foci (ACF) were evaluated histopathologically. Total number of ACF and AC, and multicrypt of ACF, and the expression of beta-catenin and COX-2 reduced significantly (p < 0.05) in all the groups treated with GBR (G2, G3 and G4) compared to the control group (G1). Spearman rank correlation test showed significant positive linear relationship between total beta-catenin and COX-2 score (Spearman's rho = 0.616, p = 0.0001). It is demonstrated that GBR inhibits the development of total number of ACF and AC, and multicrypt of ACF, reduces the expression of beta-catenin and COX-2, and thus can be a promising dietary supplement in prevention of colon cancer.
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Affiliation(s)
- Saiful Yazan Latifah
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Laboratory of Molecular Biomedicine, Institutes of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Nurdin Armania
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Tan Hern Tze
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Yaacob Azhar
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Abdul Hadi Nordiana
- Laboratory of Molecular Biomedicine, Institutes of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Saad Norazalina
- Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Ithnin Hairuszah
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Moin Saidi
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
| | - Ismail Maznah
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
- Laboratory of Molecular Biomedicine, Institutes of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia
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Vidrich A, Buzan JM, Brodrick B, Ilo C, Bradley L, Fendig KS, Sturgill T, Cohn SM. Fibroblast growth factor receptor-3 regulates Paneth cell lineage allocation and accrual of epithelial stem cells during murine intestinal development. Am J Physiol Gastrointest Liver Physiol 2009; 297:G168-78. [PMID: 19407216 PMCID: PMC2711760 DOI: 10.1152/ajpgi.90589.2008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fibroblast growth factor receptor 3 (FGFR-3) is expressed in the lower crypt epithelium, where stem cells of the intestine reside. The role of FGFR-3 signaling in regulating features of intestinal morphogenesis was examined in FGFR-3-null (FGFR-3(-/-)) mice. FGFR-3(-/-) mice had only about half the number of intestinal crypts and a marked decrease in the number of functional clonogenic stem cells, as assessed by an in vivo microcolony-forming assay, compared with wild-type littermates. A marked deficit in allocation of progenitor cells to Paneth cell differentiation was noted, although all the principal epithelial lineages were represented in FGFR-3(-/-) mice. The total cellular content and nuclear localization of beta-catenin protein were reduced in FGFR-3(-/-) mice, as was expression of cyclin D1 and matrix metalloproteinase-7, major downstream targets of beta-catenin/T cell factor-4 (Tcf-4) signaling. Activation of FGFR-3 in Caco-2 cells, an intestinal epithelial cell line, abrogated the fall in beta-catenin/Tcf-4 signaling activity that is normally observed in these cells as cultures become progressively more confluent. These findings are consistent with the hypothesis that, during intestinal development, FGFR-3 signaling regulates crypt epithelial stem cell expansion and crypt morphogenesis, as well as Paneth cell lineage specification, through beta-catenin/Tcf-4-dependent and -independent pathways.
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Affiliation(s)
- Alda Vidrich
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Jenny M. Buzan
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Brooks Brodrick
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Chibuzo Ilo
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Leigh Bradley
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Kirstin Skaar Fendig
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Thomas Sturgill
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
| | - Steven M. Cohn
- Digestive Health Center of Excellence and Department of Pharmacology, University of Virginia, Charlottesville, Virginia
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Leedham SJ, Schier S, Thliveris AT, Halberg RB, Newton MA, Wright NA. From gene mutations to tumours--stem cells in gastrointestinal carcinogenesis. Cell Prolif 2005; 38:387-405. [PMID: 16300652 PMCID: PMC6496903 DOI: 10.1111/j.1365-2184.2005.00359.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Accepted: 09/02/2005] [Indexed: 12/18/2022] Open
Abstract
Stem cells share many properties with malignant cells, such as the ability to self-renew and proliferate. Cancer is believed to be a disease of stem cells. The gastrointestinal tract has high cancer prevalence partly because of rapid epithelial cell turnover and exposure to dietary toxins. The molecular pathways of carcinogenesis differ according to the tissue. Work on hereditary cancer syndromes including familial adenomatous polyposis (FAP) has led to advances in our understanding of the events that occur in tumour development from a gastrointestinal stem cell. The initial mutation involved in the adenoma-carcinoma sequence is in the 'gatekeeper' tumour-suppressor gene adenomatous polyposis coli (APC). Somatic hits in this gene are non-random in FAP, with the type of mutation selected for by the position of the germline mutation. In the stomach, a metaplasia-dysplasia sequence occurs and is often related to Helicobacter pylori infection. Clonal expansion of mutated cells occurs by niche succession. Further expansion of the aberrant clone then occurs by the longitudinal division of crypts into two daughter units--crypt fission. Two theories seek to explain the early development of adenomas--the 'top down' and 'bottom up' hypotheses. Initial studies suggested that colorectal tumours were monoclonal; however, later work on chimeric mice and a sex chromosome mixoploid patient with FAP suggested that up to 76% of early adenomas were polyclonal. Introduction of a homozygous resistance allele has reduced tumour multiplicity in the mouse and has been used to rule out random collision of polyps as the cause of these observations. It is likely that short-range interaction between adjacent initiated crypts is responsible for polyclonality.
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Affiliation(s)
- S J Leedham
- Histopathology Unit, Cancer Research UK, London, UK.
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8
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Abstract
The intestinal tract has a rapid epithelial cell turnover, which continues throughout life. The process is regulated and maintained by a population of stem cells, which give rise to all the intestinal epithelial cell lineages. Studies in both the mouse and the human show that these cells are capable of forming clonal crypt populations. Stem cells remain hard to identify, however it is thought that they reside in a 'niche' towards the base of the crypt and their activity is regulated by the paracrine secretion of growth factors and cytokines from surrounding mesenchymal cells. Stem cell division is usually asymmetric with the formation of an identical daughter stem cell and committed progenitor cells. Progenitor cells retain the ability to divide until they terminally differentiate. Occasional symmetric division produces either 2 daughter cells with stem cell loss, or 2 stem cells and eventual clone dominance. This stochastic extinction of stem cell lines with eventual dominance of one cell line is called 'niche succession'. The discovery of plasticity, the ability of stem cells to engraft into, and in some cases replace the function of damaged host tissues has generated a large amount of scientific and clinical interest: however the concept remains controversial and is still a subject of hot debate. Studies are beginning to identify the complex molecular, genetic and cellular pathways underlying stem cell function such as Wnt signalling, bone morphogenetic protein (BMP) and Notch/Delta pathways. The derangement of these pathways within stem cells plays an integral part in the development of malignancy within the intestinal tract.
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Affiliation(s)
- S J Leedham
- Histopathology Unit, Cancer Research UK, London, WC2A 3PX, UK.
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Kim SJ, Cheung S, Hellerstein MK. Isolation of nuclei from label-retaining cells and measurement of their turnover rates in rat colon. Am J Physiol Cell Physiol 2004; 286:C1464-73. [PMID: 14960413 DOI: 10.1152/ajpcell.00139.2003] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We describe here a new technique for isolating nuclei from long-term label-retaining cells (LRCs), a subpopulation enriched with stem cells from colon, and for measuring their proliferation rates in vivo. A double-label approach was developed, combining the use of bromodeoxyuridine (BrdU) and 2H2O. Male Fisher 344 rats were administered BrdU in drinking water continuously for 2–8 wk. BrdU was then discontinued (BrdU washout), and animals ( n = 33) were switched to 2H2O in drinking water and killed after 2, 4, and 8 wk. Nuclei from BrdU-positive cells (LRCs) were collected by flow cytometry. The percentages of LRCs were 7 and 3.8% after 4 and 8 wk of BrdU washout, respectively. Turnover rates of LRCs were measured on the basis of deuterium incorporation from 2H2O into DNA of LRC nuclei, as determined by mass spectrometry. The proliferation rate of the LRCs collected was 0.33–0.90% per day (half-life of 77–210 days). Significant contamination from other potentially long-lived colon cells was excluded. In conclusion, this double-labeling method allows both physical isolation of nuclei from colon epithelial LRCs and measurement of their in vivo proliferation rates. Use of this approach may allow better understanding of mechanisms by which agents induce or protect against colon carcinogenesis.
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Affiliation(s)
- Sylvia Jeewon Kim
- Graduate Group in Molecular and Biochemical Nutrition, University of California, Berkeley, 94720, USA
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Kim KM, Shibata D. Tracing ancestry with methylation patterns: most crypts appear distantly related in normal adult human colon. BMC Gastroenterol 2004; 4:8. [PMID: 15059289 PMCID: PMC400737 DOI: 10.1186/1471-230x-4-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2003] [Accepted: 04/01/2004] [Indexed: 11/17/2022] Open
Abstract
Background The ability to discern ancestral relationships between individual human colon crypts is limited. Widely separated crypts likely trace their common ancestors to a time around birth, but closely spaced adult crypts may share more recent common ancestors if they frequently divide by fission to form clonal patches. Alternatively, adult crypts may be long-lived structures that infrequently divide or die. Methods Methylation patterns (the 5' to 3' order of methylation) at CpG sites that exhibit random changes with aging were measured from isolated crypts by bisulfite genomic sequencing. This epigenetic drift may be used to infer ancestry because recently related crypts should have similar methylation patterns. Results Methylation patterns were different between widely separated ("unrelated") crypts greater than 15 cm apart. Evidence for a more recent relationship between directly adjacent or branched crypts could not be found because their methylation pattern distances were not significantly different than widely separated crypt pairs. Methylation patterns are essentially equally different between two adult human crypts regardless of their relative locations. Conclusions Methylation patterns appear to record somatic cell trees. Starting from a single cell at conception, sequences replicate and may drift apart. Most adult human colon crypts appear to be long-lived structures that become mosaic with respect to methylation during aging.
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Affiliation(s)
- Kyoung-Mee Kim
- Department of Pathology, Norris Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Darryl Shibata
- Department of Pathology, Norris Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California, USA
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Abstract
The longevity of adult stem cells, and their potential for vast tissue regeneration, makes them a focal point of current research and debate, with future aspirations for the use of stem cells in the treatment of a number of human pathological conditions. Due to the rapid rate of cell turnover in the gastrointestinal tract, the stem cells of this tissue are amongst the most assiduous in the body, although they remain unidentified to this day due to their immature, undifferentiated phenotype. However, our knowledge of the mechanisms regulating gastrointestinal stem cell function is evolving, with the identification of putative cellular markers and the elucidation of signalling pathways which regulate cell behaviour in the normal and neoplastic gastrointestinal tract. This review describes the fundamental properties of the gastrointestinal stem cell including: (i) their number, location and origins, (ii) their primary function of deriving gastrointestinal cell lineages and maintaining tissue homeostasis, (iii) the acquisition of gastrointestinal cell lineages from adult stem cells of extraneous tissues and the consequences of this in a therapeutic context, and (iv) the genetic and morphological phenomena surrounding neoplastic transformation in the gastrointestinal tract.
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Affiliation(s)
- M Brittan
- Histopathology Unit, Cancer Research UK, London, UK.
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Wright NA. Epithelial stem cell repertoire in the gut: clues to the origin of cell lineages, proliferative units and cancer. Int J Exp Pathol 2000; 81:117-43. [PMID: 10762441 PMCID: PMC2517719 DOI: 10.1046/j.1365-2613.2000.00146.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/1999] [Accepted: 01/11/2000] [Indexed: 12/12/2022] Open
Abstract
Gastrointestinal stem cells are shown to be pluripotential and to give rise to all cell lineages in the epithelium. After damage, gut stem cells produce reparative cell lineages that produce a wide range of peptides with important actions on cell proliferation and migration, and promote regeneration and healing. Increase in stem cell number is considered to induce crypt fission, and lead to increases in the number of crypts, even in the adult; it is also the mode of spread of mutated clones in the colorectal mucosa. Stem cell repertoire is defined by both intrinsic programming of the stem cell itself, but signalling from the mesenchyme is also vitally important for defining both stem cell progeny and proliferation. Carcinogenesis in the colon occurs through sequential mutations, possibly occurring in a single cell. A case is made for this being the stem cell, but recent studies indicate that several stem cells may need to be so involved, since early lesions appear to be polyclonal in derivation.
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Affiliation(s)
- N A Wright
- ICRF Histopathology Unit, Lincoln's Inn Fields and Department of Histopathology, Imperial College School of Medicine, Hammersmith Hospital, London, UK
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Tsukamoto T, Kozaki K, Nishikawa Y, Yamamoto M, Fukami H, Inoue M, Wakabayashi K, Tatematsu M. Development and distribution of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced aberrant crypt foci in the rat large intestine. Jpn J Cancer Res 1999; 90:720-5. [PMID: 10470283 PMCID: PMC5926130 DOI: 10.1111/j.1349-7006.1999.tb00806.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Aberrant crypt foci (ACF) are generally considered to be preneoplastic lesions for colon cancer. To assess their induction by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a colon carcinogen, we performed a sequential study of ACF morphology and localization. F344 male rats were given PhIP, and methylene blue-stained colon epithelium and isolated crypts were analyzed at weeks 12, 25, 50, and 75. Each crypt was classified into 2 groups, "single" with round bottoms and "bifurcating" displaying V-shaped clefts (indicating proliferation). In combination with the number of crypts in an ACF, this classification was a good indicator for the generation of ACF in line with the fission mechanism of growth. Increasing numbers of crypts in ACF through weeks 12 to 75 and decreased percentages of ACF with bifurcating crypts at the late time points indicated that proliferation of crypts occurs predominantly during the early stages. The distribution pattern showed a significant shift (P < 0.000005) from the distal to the proximal part of the large intestine between weeks 25 and 50. Adenocarcinomas were first found to develop at week 50 in the ascending colon and cecum where bifurcating crypts were generally lacking at weeks 12 and 25. These data suggest the existence of (1) proliferating ACF which contains bifurcating crypt(s) and (2) quiescent or senescent ACF which consists of only single crypts.
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Affiliation(s)
- T Tsukamoto
- Laboratory of Pathology, Aichi Cancer Center Research Institute, Nagoya, Tokyo.
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Fujimitsu Y, Nakanishi H, Inada K, Yamachika T, Ichinose M, Fukami H, Tatematsu M. Development of aberrant crypt foci involves a fission mechanism as revealed by isolation of aberrant crypts. Jpn J Cancer Res 1996; 87:1199-203. [PMID: 9045953 PMCID: PMC5921030 DOI: 10.1111/j.1349-7006.1996.tb03133.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Morphological analysis of isolated colonic crypts in rats, postnatally, indicated that the crypts reproduce themselves by a fission mechanism, the division beginning at the crypt base and proceeding upwards until there are two separate crypts. Occasionally, before the separation is complete, a second fission process starts on one or both sides of a bifurcating crypt and a triple-branched or quadruple-branched crypt results. Analysis of isolated aberrant crypt foci (ACF) in rats treated with 1,2-dimethylhydrazine revealed that the development of ACF consisting of multiple crypts is also due to a fission mechanism. Initially, an indentation appears at the base of a single ACF crypt, with subsequent formation of a bifurcation and eventual crypt division.
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Affiliation(s)
- Y Fujimitsu
- Laboratory of Pathology, Aichi Cancer Research Institute, Chikusa-ku, Nagoya
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Totafurno J, Bjerknes M, Cheng H. The crypt cycle. Crypt and villus production in the adult intestinal epithelium. Biophys J 1987; 52:279-94. [PMID: 3663832 PMCID: PMC1330079 DOI: 10.1016/s0006-3495(87)83215-0] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We propose a model for the growth of individual crypts that is able to account for the observed changes in the number of cells in crypts under normal conditions, after irradiation, and after 30% resection. Parameter values for this model are estimated both for mouse and man, and detailed predictions of crypt growth rates are made. This model does not predict a steady-state crypt size; rather it suggests that crypts grow until they bifurcate. We therefore propose a crypt cycle (analogous to the cell cycle) and present evidence that most if not all crypts in the adult mouse are cycling asynchronously and independently. This evidence consists of four experiments that indicate that branching crypts are randomly distributed over the intestinal epithelium, that the plane of bifurcation of branching crypts is randomly oriented with respect to the villus base, and that the size distribution of crypts is consistent with an expanding crypt population. We also report for the first time evidence of villus production in the adult mouse intestinal epithelium. We conclude that the crypt and villus populations in the adult mouse are not in a steady state.
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Affiliation(s)
- J Totafurno
- Department of Anatomy, University of Toronto, Ontario, Canada
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Abstract
Stochastic theories of stem cell renewal are shown to predict turnover of intestinal crypts. While I found ample evidence of production of new crypts from direct in vivo studies in adult mice, I failed to find evidence of crypt loss. Thus, it would appear that the simple stochastic models may not provide an adequate theory of control of intestinal stem cell function.
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