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Li Y, Zhang K, Ai X, Zhang Q, Jiang L, Long J, Xu H, Feng C, Zhang Y, Tang G, Chong F, Wang L, Huang B. A Biomimetic Peptide Functions as Specific Extracellular Matrix for Quiescence of Stem Cells against Intervertebral Disc Degeneration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300578. [PMID: 37423970 DOI: 10.1002/smll.202300578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 05/03/2023] [Indexed: 07/11/2023]
Abstract
Maintaining quiescence of stem cells is a potential way to decrease cell nutrition demand for restoring the organization. Herein, a biomimetic peptide to maintain quiescence of stem cells through C-X-C motif chemokine ligand 8 (CXCL8)-C-X-C motif chemokine receptor 1 (CXCR1) pathway against intervertebral disc degeneration (IVDD) is developed. First, it is confirmed that quiescence can be induced via inhibiting phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway in nucleus pulposus stem cells (NPSCs). Meanwhile, it is well known that CXCR1, a chemokine receptor, can be targeted by CXCL8, resulting in cell proliferation via activating PI3K/Akt/mTOR pathway. Second, a biomimetic peptide (OAFF) that can bind to CXCR1 and form fibrous networks on NPSCs, mimicking extracellular matrix formation is developed. The multivalent effect and long-term binding to CXCR1 on NPSCs of OAFF fibers offer forcefully competitive inhibition with natural CXCL8, which induces NPSCs quiescence and ultimately overcomes obstacle in intradiscal injection therapy. In rat caudal disc puncture model, OAFF nanofibers still maintain at 5 weeks after operation and inhibit degeneration process of intervertebral disc in terms of histopathology and imageology. In situ fibrillogenesis of biomimetic peptide on NPSCs provides promising stem cells for intradiscal injection therapy against IVDD.
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Affiliation(s)
- Yuan Li
- Department of Orthopedics, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
| | - Kuo Zhang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST), Beijing, 100190, P. R. China
| | - Xuezheng Ai
- Department of Orthopedics, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
| | - Qingshi Zhang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST), Beijing, 100190, P. R. China
| | - Lu Jiang
- Clinical Medicine Research Center, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
| | - Jiang Long
- Department of Orthopedics, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
| | - Huange Xu
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST), Beijing, 100190, P. R. China
| | - Chencheng Feng
- Department of Orthopedics, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
| | - Yaqing Zhang
- Department of Orthopedics, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
| | - Guoke Tang
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, 200080, P. R. China
| | - Fanli Chong
- Department of Orthopedics, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
| | - Lei Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST), Beijing, 100190, P. R. China
| | - Bo Huang
- Department of Orthopedics, Xinqiao Hospital, Army Medical University, Chongqing, 400037, P. R. China
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Fontana F, Raimondi M, Marzagalli M, Sommariva M, Gagliano N, Limonta P. Three-Dimensional Cell Cultures as an In Vitro Tool for Prostate Cancer Modeling and Drug Discovery. Int J Mol Sci 2020; 21:E6806. [PMID: 32948069 PMCID: PMC7554845 DOI: 10.3390/ijms21186806] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 02/07/2023] Open
Abstract
In the last decade, three-dimensional (3D) cell culture technology has gained a lot of interest due to its ability to better recapitulate the in vivo organization and microenvironment of in vitro cultured cancer cells. In particular, 3D tumor models have demonstrated several different characteristics compared with traditional two-dimensional (2D) cultures and have provided an interesting link between the latter and animal experiments. Indeed, 3D cell cultures represent a useful platform for the identification of the biological features of cancer cells as well as for the screening of novel antitumor agents. The present review is aimed at summarizing the most common 3D cell culture methods and applications, with a focus on prostate cancer modeling and drug discovery.
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MESH Headings
- Adenocarcinoma/drug therapy
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Androgens
- Animals
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Cell Culture Techniques/instrumentation
- Cell Culture Techniques/methods
- Cell Hypoxia
- Drug Discovery/methods
- Drug Screening Assays, Antitumor/instrumentation
- Drug Screening Assays, Antitumor/methods
- Energy Metabolism
- Epithelial-Mesenchymal Transition
- Extracellular Matrix/metabolism
- Humans
- Inflammation
- Male
- Molecular Targeted Therapy
- Monitoring, Immunologic
- Neoplasm Metastasis
- Neoplasm Proteins/metabolism
- Neoplasms, Hormone-Dependent/drug therapy
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/pathology
- Neoplastic Stem Cells/cytology
- Neoplastic Stem Cells/drug effects
- Neoplastic Stem Cells/metabolism
- Neovascularization, Pathologic/drug therapy
- Oxidation-Reduction
- Prostatic Neoplasms/drug therapy
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- Prostatic Neoplasms/therapy
- Spheroids, Cellular/drug effects
- Therapies, Investigational
- Tumor Cells, Cultured
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Affiliation(s)
- Fabrizio Fontana
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milan, Italy; (M.R.); (M.M.); (P.L.)
| | - Michela Raimondi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milan, Italy; (M.R.); (M.M.); (P.L.)
| | - Monica Marzagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milan, Italy; (M.R.); (M.M.); (P.L.)
| | - Michele Sommariva
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, via Mangiagalli 31, 20133 Milan, Italy; (M.S.); (N.G.)
| | - Nicoletta Gagliano
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, via Mangiagalli 31, 20133 Milan, Italy; (M.S.); (N.G.)
| | - Patrizia Limonta
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milan, Italy; (M.R.); (M.M.); (P.L.)
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Escue R, Kandasamy K, Parthasarathi K. Thrombin Induces Inositol Trisphosphate-Mediated Spatially Extensive Responses in Lung Microvessels. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:921-935. [PMID: 28188112 DOI: 10.1016/j.ajpath.2016.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 12/09/2016] [Accepted: 12/20/2016] [Indexed: 12/20/2022]
Abstract
Activation of plasma membrane receptors initiates compartmentalized second messenger signaling. Whether this compartmentalization facilitates the preferential intercellular diffusion of specific second messengers is unclear. Toward this, the receptor-mediated agonist, thrombin, was instilled into microvessels in a restricted region of isolated blood-perfused mouse lungs. Subsequently, the thrombin-induced increase in endothelial F-actin was determined using confocal fluorescence microscopy. Increased F-actin was evident in microvessels directly treated with thrombin and in those located in adjoining thrombin-free regions. This increase was abrogated by inhibiting inositol trisphosphate-mediated calcium release with Xestospongin C (XeC). XeC also inhibited the thrombin-induced increase in the amplitude of endothelial cytosolic Ca2+ oscillations. Instillation of thrombin and XeC into adjacent restricted regions increased F-actin in microvessels in the thrombin-treated and adjacent regions but not in those in the XeC-treated region. Thus, inositol trisphosphate, and not calcium, diffused interendothelially to the spatially remote thrombin-free microvessels. Thus, activation of plasma membrane receptors increased the ambit of inflammatory responses via a second messenger different from that used by stimuli that induce cell-wide increases in second messengers. Thrombin however failed to induce the spatially extensive response in microvessels of mice lacking endothelial connexin43, suggesting a role for connexin43 gap junctions. Compartmental second messenger signaling and interendothelial communication define the specific second messenger involved in exacerbating proinflammatory responses to receptor-mediated agonists.
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Affiliation(s)
- Rachel Escue
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Kathirvel Kandasamy
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Kaushik Parthasarathi
- Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee.
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Gravelle P, Jean C, Familiades J, Decaup E, Blanc A, Bezombes-Cagnac C, Laurent C, Savina A, Fournié JJ, Laurent G. Cell growth in aggregates determines gene expression, proliferation, survival, chemoresistance, and sensitivity to immune effectors in follicular lymphoma. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 184:282-95. [PMID: 24231431 DOI: 10.1016/j.ajpath.2013.09.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 09/23/2013] [Accepted: 09/26/2013] [Indexed: 01/03/2023]
Abstract
Lymphomas grow as dense aggregates in patients, but whether this spatial organization affects lymphoma cell biology is unknown. We grew follicular lymphoma (FL) cells in vitro as multicellular aggregates of lymphoma cells to investigate this question. Gene expression analysis revealed that 612 genes were differentially expressed when cells grew in multicellular aggregates of lymphoma cells rather than in suspension. These genes correspond to several GO biological processes, such as hypoxia, activation of NF-κB pathway, and negative regulation of cell cycle, a gene signature also found in the transcriptomes from FL biopsies. Pimonidazole staining, HIF-1A accumulation, and VEGFA release confirmed that cells in multicellular aggregates of lymphoma cells actually respond to hypoxia. In adaptation to such conditions, they also displayed an activated NF-κB pathway and a quiescent status far more frequently than in suspension. When cultured in three dimensions, FL cells display resistance to doxorubicin and bendamustine, two drugs largely used in FL therapy, compared to FL cultured in suspension. Finally, multicellular aggregates of lymphoma cells were also found to be less sensitive to purified natural killer cells. To conclude, our study shows that in FL, spatial organization results in dramatic changes in FL biology, including gene expression, proliferation, drug resistance, and immune escape.
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Affiliation(s)
- Pauline Gravelle
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France.
| | - Christine Jean
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France
| | - Julien Familiades
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France
| | - Emilie Decaup
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France; Roche Research Institute, Boulogne Billancourt, France
| | - Amandine Blanc
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France
| | - Christine Bezombes-Cagnac
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France
| | - Camille Laurent
- University of Toulouse III: Paul Sabatier, Toulouse, France; INSERM UMR1047, Center for Pathophysiology of Toulouse Purpan, Toulouse, France; Department of Anatomopathology, Hospital Purpan, Toulouse, France
| | | | - Jean-Jacques Fournié
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France
| | - Guy Laurent
- National Institute of Health and Medical Research (INSERM) UMR1037-Cancer, Research Center of Toulouse, Toulouse, France; University of Toulouse III: Paul Sabatier, Toulouse, France; National Center for Scientific Research ERL 5294, Toulouse, France; Carnot Lymphoma Institute (CALYM), Toulouse, France; Laboratoire d'Excellence Toulouse Cancer: TOUCAN, Toulouse, France; Department of Hematology, Hospital Purpan, Toulouse, France
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Mandujano-Tinoco EA, Gallardo-Pérez JC, Marín-Hernández A, Moreno-Sánchez R, Rodríguez-Enríquez S. Anti-mitochondrial therapy in human breast cancer multi-cellular spheroids. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013. [DOI: 10.1016/j.bbamcr.2012.11.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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Gallardo-Pérez JC, Espinosa M, Ceballos-Cancino G, Daniel A, Rodríguez-Enríquez S, Aviles A, Moreno-Sánchez R, Melendez-Zajgla J, Maldonado V. NF-kappa B is required for the development of tumor spheroids. J Cell Biochem 2010; 108:169-80. [PMID: 19562673 DOI: 10.1002/jcb.22237] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Tumor cells cultured in three-dimensional models provide a more realistic and biologically meaningful analysis of the initial phases of cancer development and drug resistance. Several studies have demonstrated that culture of cancer cells in three dimensions induces cellular resistance to a variety of anti-neoplastic drugs by poorly understood mechanisms. The role of the transcription factor NF-kappaB and inhibitors of apoptosis proteins (IAPs) in the onset and development of drug resistance during tumor spheroid growth has not been established. In this work, we found a significant increase in the activity and expression of NF-kappaB and its downstream target XIAP (X-linked IAP) in cancer cells grown as multi-cellular tumor spheroids. Blocking XIAP expression with RNA interference markedly increased the sensitivity of cancer tumor spheroid cells toward anti-neoplastic drugs, indicating a role for IAPs in establishing drug resistance. In turn, inhibition of NF-kappaB by negative dominants suppressed spheroid formation, whereas overexpression of the upstream kinase IkappaBKbeta increased their growth and resistance. The present data suggested that NF-kappaB and its downstream target XIAP were essential for the growth and drug resistance of small avascular tumor.
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Affiliation(s)
- J C Gallardo-Pérez
- Molecular Biology Laboratory, Sub-Direction of Basic Research, National Institute of Cancerology, Mexico City, Mexico
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7
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Hoffmann EK, Lambert IH, Pedersen SF. Physiology of cell volume regulation in vertebrates. Physiol Rev 2009; 89:193-277. [PMID: 19126758 DOI: 10.1152/physrev.00037.2007] [Citation(s) in RCA: 1014] [Impact Index Per Article: 67.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The ability to control cell volume is pivotal for cell function. Cell volume perturbation elicits a wide array of signaling events, leading to protective (e.g., cytoskeletal rearrangement) and adaptive (e.g., altered expression of osmolyte transporters and heat shock proteins) measures and, in most cases, activation of volume regulatory osmolyte transport. After acute swelling, cell volume is regulated by the process of regulatory volume decrease (RVD), which involves the activation of KCl cotransport and of channels mediating K(+), Cl(-), and taurine efflux. Conversely, after acute shrinkage, cell volume is regulated by the process of regulatory volume increase (RVI), which is mediated primarily by Na(+)/H(+) exchange, Na(+)-K(+)-2Cl(-) cotransport, and Na(+) channels. Here, we review in detail the current knowledge regarding the molecular identity of these transport pathways and their regulation by, e.g., membrane deformation, ionic strength, Ca(2+), protein kinases and phosphatases, cytoskeletal elements, GTP binding proteins, lipid mediators, and reactive oxygen species, upon changes in cell volume. We also discuss the nature of the upstream elements in volume sensing in vertebrate organisms. Importantly, cell volume impacts on a wide array of physiological processes, including transepithelial transport; cell migration, proliferation, and death; and changes in cell volume function as specific signals regulating these processes. A discussion of this issue concludes the review.
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Affiliation(s)
- Else K Hoffmann
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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Lange K, Gartzke J. F-actin-based Ca signaling-a critical comparison with the current concept of Ca signaling. J Cell Physiol 2006; 209:270-87. [PMID: 16823881 DOI: 10.1002/jcp.20717] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A short comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect, the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating endoplasmic/sarcoplasmic reticulum-derived vesicles equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive channel-receptors for Ca-release. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of actin filaments. Cellular sites of F-actin-based Ca storage are microvilli and the submembrane cytoskeleton. Several specific features of Ca signaling such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release (CICR), which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling.
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Alarcón T, Marches R, Page KM. Mathematical models of the fate of lymphoma B cells after antigen receptor ligation with specific antibodies. J Theor Biol 2005; 240:54-71. [PMID: 16214175 DOI: 10.1016/j.jtbi.2005.08.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Revised: 08/24/2005] [Accepted: 08/25/2005] [Indexed: 11/19/2022]
Abstract
We formulate models of the mechanism(s) by which B cell lymphoma cells stimulated with an antibody specific to the B cell receptor (IgM) become quiescent or apoptotic. In particular, we aim to reproduce experimental results by Marches et al. according to which the fate of the targeted cells (Daudi) depends on the levels of expression of p21(Waf1) (p21) cell-cycle inhibitor. A simple model is formulated in which the basic ingredients are p21 and caspase activity, and their mutual inhibition. We show that this model does not reproduce the experimental results and that further refinement is needed. A second model successfully reproduces the experimental observations, for a given set of parameter values, indicating a critical role for Myc in the fate decision process. We use bifurcation analysis and objective sensitivity analysis to assess the robustness of our results. Importantly, this analysis yields experimentally testable predictions on the role of Myc, which could have therapeutic implications.
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Affiliation(s)
- Tomás Alarcón
- Bioinformatics Unit, Department of Computer Science, University College London, London WC1E 6BT, UK.
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Alarcón T, Byrne HM, Maini PK. A mathematical model of the effects of hypoxia on the cell-cycle of normal and cancer cells. J Theor Biol 2004; 229:395-411. [PMID: 15234206 DOI: 10.1016/j.jtbi.2004.04.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Revised: 03/23/2004] [Accepted: 04/08/2004] [Indexed: 12/21/2022]
Abstract
The evolution of the cell-cycle is known to be influenced by environmental conditions, including lack of extracellular oxygen (hypoxia). Notably, hypoxia appears to have different effects on normal and cancer cells. Whereas both experience hypoxia-induced arrest of the G1 phase of the cell-cycle (i.e. delay in the transition through the restriction point), experimental evidence suggests that only cancer cells undergo hypoxia-induced quiescence (i.e. the transition of the cell to a latent state in which most of the cell functions, including proliferation, are suspended). Here, we extend a model for the cell-cycle due to Tyson and Novak (J. Theor. Biol. 210 (2001) 249) to account for the action of the protein p27. This protein, whose expression is upregulated under hypoxia, inhibits the activation of the cyclin dependent kinases (CDKs), thus preventing DNA synthesis and delaying the normal progression through the cell-cycle. We use a combination of numerical and analytic techniques to study our model. We show that it reproduces many features of the response to hypoxia of normal and cancer cells, as well as generating experimentally testable predictions. For example our model predicts that cancer cells can undergo quiescence by increasing their levels of p27, whereas for normal cells p27 expression decreases when the cellular growth rate increases.
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Affiliation(s)
- T Alarcón
- Centre for Mathematical Biology, Mathematical Institute, University of Oxford, 24-29 St Giles', Oxford OX1 3LB, UK.
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Pedersen SF, Mills JW, Hoffmann EK. Role of the F-actin cytoskeleton in the RVD and RVI processes in Ehrlich ascites tumor cells. Exp Cell Res 1999; 252:63-74. [PMID: 10502400 DOI: 10.1006/excr.1999.4615] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of the F-actin cytoskeleton in cell volume regulation was studied in Ehrlich ascites tumor cells, using a quantitative rhodamine-phalloidin assay, confocal laser scanning microscopy, and electronic cell sizing. A hypotonic challenge (160 mOsm) was associated with a decrease in cellular F-actin content at 1 and 3 min and a hypertonic challenge (600 mOsm) with an increase in cellular F-actin content at 1, 3, and 5 min, respectively, compared to isotonic (310 mOsm) control cells. Confocal visualization of F-actin in fixed, intact Ehrlich cells demonstrated that osmotic challenges mainly affect the F-actin in the cortical region of the cells, with no visible changes in F-actin in other cell regions. The possible role of the F-actin cytoskeleton in RVD was studied using 0. 5 microM cytochalasin B (CB), cytochalasin D (CD), or chaetoglobosin C (ChtC), a cytochalasin analog with little or no affinity for F-actin. Recovery of cell volume after hypotonic swelling was slower in cells pretreated for 3 min with 0.5 microM CB, but not in CD- and ChtC-treated cells, compared to osmotically swollen control cells. Moreover, the maximal cell volume after swelling was decreased in CB-treated, but not in CD- or Chtc-treated cells. Following a hypertonic challenge imposed using the RVD/RVI protocol, recovery from cell shrinkage was slower in CB-treated, but not in CD- or Chtc-treated cells, whereas the minimal cell volume after shrinkage was unaltered by either of these treatments. It is concluded that osmotic cell swelling and shrinkage elicit a decrease and an increase in the F-actin content in Ehrlich cells, respectively. The RVD and RVI processes are inhibited by 0.5 microM CB, but not by 0.5 microM CD, which is more specific for actin.
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Affiliation(s)
- S F Pedersen
- Biochemistry Department, August Krogh Institute, Copenhagen, DK-2100, Denmark.
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Wartenberg M, Diedershagen H, Hescheler J, Sauer H. Growth stimulation versus induction of cell quiescence by hydrogen peroxide in prostate tumor spheroids is encoded by the duration of the Ca(2+) response. J Biol Chem 1999; 274:27759-67. [PMID: 10488120 DOI: 10.1074/jbc.274.39.27759] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
With increasing size, multicellular prostate tumor spheroids develop regions of quiescent, multidrug-resistant cells expressing the cyclin-dependent kinase inhibitor p27(kip1). Treatment of small (diameter 60 +/- 20 micrometer) spheroids with 200 microM hydrogen peroxide (H(2)O(2)) resulted in cell cycle arrest owing to up-regulation of p27(kip1) and down-regulation of the transcription factor c-Fos. Incubation with 100 nM-1 microM H(2)O(2) led to up-regulation of c-Fos and enhanced tumor growth. Growth stimulation was inhibited by bisindolylmaleimide I, indicating a role for protein kinase C in the signaling cascade that involved the mitogen-activated protein kinase members MEK1,2, ERK1, -2, and c-Jun N-terminal kinase. Changes in Ca(2+) influx underlined the differential effects of H(2)O(2). Incubation with 200 microM H(2)O(2) released [Ca(2+)](i) from intracellular stores followed by prolonged Ca(2+) influx. Inhibition of influx by Ca(2+)-free media or Ni(2+), La(3+), Mn(2+) and SKF-96365 prevented the induction of quiescence and stimulated spheroid growth. Consequently, treatment with 200 microM H(2)O(2) in Ca(2+)-free media down-regulated p27(kip1) and increased Fos protein. ATP exerted effects comparably to those observed with H(2)O(2). Encoding growth stimulation by [Ca(2+)](i) release and induction of cell quiescence by prolonged Ca(2+) influx may provide a general mechanism for the control of tumor growth.
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Affiliation(s)
- M Wartenberg
- Department of Neurophysiology, University of Cologne, D-50931 Cologne, Germany
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