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An Insight into GPCR and G-Proteins as Cancer Drivers. Cells 2021; 10:cells10123288. [PMID: 34943797 PMCID: PMC8699078 DOI: 10.3390/cells10123288] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 12/14/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are the largest family of cell surface signaling receptors known to play a crucial role in various physiological functions, including tumor growth and metastasis. Various molecules such as hormones, lipids, peptides, and neurotransmitters activate GPCRs that enable the coupling of these receptors to highly specialized transducer proteins, called G-proteins, and initiate multiple signaling pathways. Integration of these intricate networks of signaling cascades leads to numerous biochemical responses involved in diverse pathophysiological activities, including cancer development. While several studies indicate the role of GPCRs in controlling various aspects of cancer progression such as tumor growth, invasion, migration, survival, and metastasis through its aberrant overexpression, mutations, or increased release of agonists, the explicit mechanisms of the involvement of GPCRs in cancer progression is still puzzling. This review provides an insight into the various responses mediated by GPCRs in the development of cancers, the molecular mechanisms involved and the novel pharmacological approaches currently preferred for the treatment of cancer. Thus, these findings extend the knowledge of GPCRs in cancer cells and help in the identification of therapeutics for cancer patients.
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Eftekhari R, de Lima SG, Liu Y, Mihara K, Saifeddine M, Noorbakhsh F, Scarisbrick IA, Hollenberg MD. Microenvironment proteinases, proteinase-activated receptor regulation, cancer and inflammation. Biol Chem 2019; 399:1023-1039. [PMID: 29924723 DOI: 10.1515/hsz-2018-0001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 06/08/2018] [Indexed: 12/17/2022]
Abstract
We propose that in the microenvironment of inflammatory tissues, including tumours, extracellular proteinases can modulate cell signalling in part by regulating proteinase-activated receptors (PARs). We have been exploring this mechanism in a variety of inflammation and tumour-related settings that include tumour-derived cultured cells from prostate and bladder cancer, as well as immune inflammatory cells that are involved in the pathology of inflammatory diseases including multiple sclerosis. Our work showed that proteinase signalling via the PARs affects prostate and bladder cancer-derived tumour cell behaviour and can regulate calcium signalling in human T-cell and macrophage-related inflammatory cells as well as in murine splenocytes. Further, we found that the tumour-derived prostate cancer cells and immune-related cells (Jurkat, THP1, mouse splenocytes) can produce PAR-regulating proteinases (including kallikreins: kallikrein-related peptidases), that can control tissue function by both a paracrine and autocrine mechanism. We suggest that this PAR-driven signalling process involving secreted microenvironment proteinases can play a key role in cancer and inflammatory diseases including multiple sclerosis.
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Affiliation(s)
- Rahil Eftekhari
- Inflammation Research Network-Snyder Institute for Chronic Disease, Departments of Physiology and Pharmacology and Medicine, University of Calgary Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.,Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran 1416753955, Iran
| | - Stacy G de Lima
- Inflammation Research Network-Snyder Institute for Chronic Disease, Departments of Physiology and Pharmacology and Medicine, University of Calgary Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Yu Liu
- Inflammation Research Network-Snyder Institute for Chronic Disease, Departments of Physiology and Pharmacology and Medicine, University of Calgary Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Koichiro Mihara
- Inflammation Research Network-Snyder Institute for Chronic Disease, Departments of Physiology and Pharmacology and Medicine, University of Calgary Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Mahmoud Saifeddine
- Inflammation Research Network-Snyder Institute for Chronic Disease, Departments of Physiology and Pharmacology and Medicine, University of Calgary Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Farshid Noorbakhsh
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran 1416753955, Iran
| | - Isobel A Scarisbrick
- Department of Physical Medicine and Rehabilitation, Rehabilitation Medicine Research Center, Mayo Clinic, Rochester, MN 55905, USA
| | - Morley D Hollenberg
- Inflammation Research Network-Snyder Institute for Chronic Disease, Departments of Physiology and Pharmacology and Medicine, University of Calgary Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
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Cancer driver G-protein coupled receptor (GPCR) induced β-catenin nuclear localization: the transcriptional junction. Cancer Metastasis Rev 2019; 37:147-157. [PMID: 29222765 DOI: 10.1007/s10555-017-9711-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G protein-coupled receptors (GPCRs) comprise the main signal-transmitting components in the cell membrane. Over the past several years, biochemical and structural analyses have immensely enhanced our knowledge of GPCR involvement in health and disease states. The present review focuses on GPCRs that are cancer drivers, involved in tumor growth and development. Our aim is to highlight the involvement of stabilized β-catenin molecular machinery with a specific array of GPCRs. We discuss recent advances in understanding the molecular path leading to β-catenin nuclear localization and transcriptional activity and their implications for future cancer therapy research.
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Ramachandran R, Altier C, Oikonomopoulou K, Hollenberg MD. Proteinases, Their Extracellular Targets, and Inflammatory Signaling. Pharmacol Rev 2016; 68:1110-1142. [PMID: 27677721 DOI: 10.1124/pr.115.010991] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Given that over 2% of the human genome codes for proteolytic enzymes and their inhibitors, it is not surprising that proteinases serve many physiologic-pathophysiological roles. In this context, we provide an overview of proteolytic mechanisms regulating inflammation, with a focus on cell signaling stimulated by the generation of inflammatory peptides; activation of the proteinase-activated receptor (PAR) family of G protein-coupled receptors (GPCR), with a mechanism in common with adhesion-triggered GPCRs (ADGRs); and by proteolytic ion channel regulation. These mechanisms are considered in the much wider context that proteolytic mechanisms serve, including the processing of growth factors and their receptors, the regulation of matrix-integrin signaling, and the generation and release of membrane-tethered receptor ligands. These signaling mechanisms are relevant for inflammatory, neurodegenerative, and cardiovascular diseases as well as for cancer. We propose that the inflammation-triggering proteinases and their proteolytically generated substrates represent attractive therapeutic targets and we discuss appropriate targeting strategies.
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Affiliation(s)
- Rithwik Ramachandran
- Inflammation Research Network-Snyder Institute for Chronic Disease, Department of Physiology & Pharmacology (R.R., C.A., M.D.H.) and Department of Medicine (M.D.H.),University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada; Department of Pathology and Laboratory Medicine, Toronto Western Hospital, Toronto, Ontario, Canada (K.O.); and Department of Physiology and Pharmacology, Western University, London, Ontario, Canada (R.R.)
| | - Christophe Altier
- Inflammation Research Network-Snyder Institute for Chronic Disease, Department of Physiology & Pharmacology (R.R., C.A., M.D.H.) and Department of Medicine (M.D.H.),University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada; Department of Pathology and Laboratory Medicine, Toronto Western Hospital, Toronto, Ontario, Canada (K.O.); and Department of Physiology and Pharmacology, Western University, London, Ontario, Canada (R.R.)
| | - Katerina Oikonomopoulou
- Inflammation Research Network-Snyder Institute for Chronic Disease, Department of Physiology & Pharmacology (R.R., C.A., M.D.H.) and Department of Medicine (M.D.H.),University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada; Department of Pathology and Laboratory Medicine, Toronto Western Hospital, Toronto, Ontario, Canada (K.O.); and Department of Physiology and Pharmacology, Western University, London, Ontario, Canada (R.R.)
| | - Morley D Hollenberg
- Inflammation Research Network-Snyder Institute for Chronic Disease, Department of Physiology & Pharmacology (R.R., C.A., M.D.H.) and Department of Medicine (M.D.H.),University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada; Department of Pathology and Laboratory Medicine, Toronto Western Hospital, Toronto, Ontario, Canada (K.O.); and Department of Physiology and Pharmacology, Western University, London, Ontario, Canada (R.R.)
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Abstract
Although many studies have demonstrated that components of the hemostatic system may be involved in signaling leading to cancer progression, the potential mechanisms by which they contribute to cancer dissemination are not yet precisely understood. Among known coagulant factors, tissue factor (TF) and thrombin play a pivotal role in cancer invasion. They may be generated in the tumor microenvironment independently of blood coagulation and can induce cell signaling through activation of protease-activated receptors (PARs). PARs are transmembrane G-protein-coupled receptors (GPCRs) that are activated by a unique proteolytic mechanism. They play important roles in vascular physiology, neural tube closure, hemostasis, and inflammation. All of these agents (TF, thrombin, PARs—mainly PAR-1 and PAR-2) are thought to promote cancer invasion and metastasis at least in part by facilitating tumor cell migration, angiogenesis, and interactions with host vascular cells, including platelets, fibroblasts, and endothelial cells lining blood vessels. Here, we discuss the role of PARs and their activators in cancer progression, focusing on TF- and thrombin-mediated actions. Therapeutic options tailored specifically to inhibit PAR-induced signaling in cancer patients are presented as well.
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G Protein-Coupled Receptors in Cancer. Int J Mol Sci 2016; 17:ijms17081320. [PMID: 27529230 PMCID: PMC5000717 DOI: 10.3390/ijms17081320] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/21/2016] [Accepted: 08/08/2016] [Indexed: 12/12/2022] Open
Abstract
Despite the fact that G protein-coupled receptors (GPCRs) are the largest signal-conveying receptor family and mediate many physiological processes, their role in tumor biology is underappreciated. Numerous lines of evidence now associate GPCRs and their downstream signaling targets in cancer growth and development. Indeed, GPCRs control many features of tumorigenesis, including immune cell-mediated functions, proliferation, invasion and survival at the secondary site. Technological advances have further substantiated GPCR modifications in human tumors. Among these are point mutations, gene overexpression, GPCR silencing by promoter methylation and the number of gene copies. At this point, it is imperative to elucidate specific signaling pathways of “cancer driver” GPCRs. Emerging data on GPCR biology point to functional selectivity and “biased agonism”; hence, there is a diminishing enthusiasm for the concept of “one drug per GPCR target” and increasing interest in the identification of several drug options. Therefore, determining the appropriate context-dependent conformation of a functional GPCR as well as the contribution of GPCR alterations to cancer development remain significant challenges for the discovery of dominant cancer genes and the development of targeted therapeutics.
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Bar-Shavit R, Maoz M, Kancharla A, Jaber M, Agranovich D, Grisaru-Granovsky S, Uziely B. Protease-activated receptors (PARs) in cancer: Novel biased signaling and targets for therapy. Methods Cell Biol 2015; 132:341-58. [PMID: 26928551 DOI: 10.1016/bs.mcb.2015.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Despite the fact that G protein-coupled receptors (GPCRs) mediate numerous physiological processes and represent targets for therapeutics for a vast array of diseases, their role in tumor biology is under appreciated. Protease-activated receptors (PARs) form a family which belongs to GPCR class A. PAR1&2 emerge with a central role in epithelial malignancies. Although the part of PAR1&2 in cancer is on the rise, their underlying signaling events are poorly understood. We review hereby past, present, and future cancer-associated PAR biology. Mainly, their role in physiological (placenta-cytotophobalst) and patho-physiological invasion processes. The identification and characterization of signal pleckstrin homology (PH)-domain-binding motifs established critical sites for breast cancer growth in PAR1&2. Among the proteins found to harbor important PH-domains and are involved in PAR biology are Akt/PKB as also Etk/Bmx and Vav3. A point mutation in PAR2, H349A, but not R352A, abrogated PH-protein association and is sufficient to markedly reduce PAR2-instigated breast tumor growth in vivo as also placental extravillous trophoblast (EVT) invasion in vitro is markedly reduced. Similarly, the PAR1 mutant hPar1-7A, which is unable to bind PH-domain, inhibits mammary tumors and EVT invasion, endowing these motifs with physiological significance and underscoring the importance of these previously unknown PAR1 and PAR2 PH-domain-binding motifs in both pathological and physiological invasion processes.
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Affiliation(s)
- R Bar-Shavit
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - M Maoz
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - A Kancharla
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - M Jaber
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - D Agranovich
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | | | - B Uziely
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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8
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Hollenberg MD. Proteinases, their receptors and inflammatory signalling: the Oxford South Parks Road connection. Br J Pharmacol 2014; 172:3196-211. [PMID: 25521749 DOI: 10.1111/bph.13041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 11/18/2014] [Accepted: 12/07/2014] [Indexed: 01/22/2023] Open
Abstract
In keeping with the aim of the Paton Memorial Lecture to 'facilitate the historical study of pharmacology', this overview, which is my distinct honour to write, represents a 'Janus-like' personal perspective looking both backwards and forwards at the birth and growth of 'receptor molecular pharmacology' with special relevance to inflammatory diseases. The overview begins in the Oxford Department of Pharmacology in the mid-1960s and then goes on to provide a current perspective of signalling by proteinases. Looking backwards, the synopsis describes the fruitful Oxford Pharmacology Department infrastructure that Bill Paton generated in keeping with the blueprint begun by his predecessor, J H Burn. Looking forwards, the overview illustrates the legacy of that environment in generating some of the first receptor ligand-binding data and providing the inspiration and vision for those like me who were training in the department at the same time. With apologies, I mention only in passing a number of individuals who benefitted from the 'South Parks Road connection' using myself as one of the 'outcome study' examples. It is also by looking forward that I can meet the complementary aim of summarizing the lecture presented at a 'BPS 2014 Focused Meeting on Cell Signalling' to provide an overview of the role of proteinases and their signalling mechanisms in the setting of inflammation.
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Affiliation(s)
- M D Hollenberg
- Inflammation Research Network-Snyder Institute for Chronic Disease, Department of Physiology and Pharmacology and Department of Medicine, University of Calgary Cumming School of Medicine, Calgary, AB, Canada
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Hollenberg MD, Mihara K, Polley D, Suen JY, Han A, Fairlie DP, Ramachandran R. Biased signalling and proteinase-activated receptors (PARs): targeting inflammatory disease. Br J Pharmacol 2014; 171:1180-94. [PMID: 24354792 DOI: 10.1111/bph.12544] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 11/13/2013] [Accepted: 11/26/2013] [Indexed: 12/13/2022] Open
Abstract
Although it has been known since the 1960s that trypsin and chymotrypsin can mimic hormone action in tissues, it took until the 1990s to discover that serine proteinases can regulate cells by cleaving and activating a unique four-member family of GPCRs known as proteinase-activated receptors (PARs). PAR activation involves the proteolytic exposure of its N-terminal receptor sequence that folds back to function as a 'tethered' receptor-activating ligand (TL). A key N-terminal arginine in each of PARs 1 to 4 has been singled out as a target for cleavage by thrombin (PARs 1, 3 and 4), trypsin (PARs 2 and 4) or other proteases to unmask the TL that activates signalling via Gq , Gi or G12 /13 . Similarly, synthetic receptor-activating peptides, corresponding to the exposed 'TL sequences' (e.g. SFLLRN-, for PAR1 or SLIGRL- for PAR2) can, like proteinase activation, also drive signalling via Gq , Gi and G12 /13 , without requiring receptor cleavage. Recent data show, however, that distinct proteinase-revealed 'non-canonical' PAR tethered-ligand sequences and PAR-activating agonist and antagonist peptide analogues can induce 'biased' PAR signalling, for example, via G12 /13 -MAPKinase instead of Gq -calcium. This overview summarizes implications of this 'biased' signalling by PAR agonists and antagonists for the recognized roles the PARs play in inflammatory settings.
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Affiliation(s)
- M D Hollenberg
- Inflammation Research Network-Snyder Institute for Chronic Disease, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada; Faculty of Medicine, Department of Medicine, University of Calgary, Calgary, AB, Canada
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10
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Cottrell GS. Roles of proteolysis in regulation of GPCR function. Br J Pharmacol 2013; 168:576-90. [PMID: 23043558 DOI: 10.1111/j.1476-5381.2012.02234.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 09/03/2012] [Accepted: 09/24/2012] [Indexed: 12/18/2022] Open
Abstract
The enzymatic activity of peptidases must be tightly regulated to prevent uncontrolled hydrolysis of peptide bonds, which could have devastating effects on biological systems. Peptidases are often generated as inactive propeptidases, secreted with endogenous inhibitors, or they are compartmentalized. Propeptidases become active after proteolytic removal of N-terminal activation peptides by other peptidases. Some peptidases only become active towards substrates only at certain pHs, thus confining activity to specific compartments or conditions. This review discusses the different roles proteolysis plays in regulating GPCRs. At the cell-surface, certain GPCRs are regulated by the hydrolytic inactivation of bioactive peptides by membrane-anchored peptidases, which prevent signalling. Conversely, cell-surface peptidases can also generate bioactive peptides, which directly activate GPCRs. Alternatively, cell-surface peptidases activated by GPCRs, can generate bioactive peptides to cause transactivation of receptor tyrosine kinases, thereby promoting signalling. Certain peptidases can signal directly to cells, by cleaving GPCR to initiate intracellular signalling cascades. Intracellular peptidases also regulate GPCRs; lysosomal peptidases destroy GPCRs in lysosomes to permanently terminate signalling and mediate down-regulation; endosomal peptidases cleave internalized peptide agonists to regulate GPCR recycling, resensitization and signalling; and soluble intracellular peptidases also participate in GPCR function by regulating the ubiquitination state of GPCRs, thereby altering GPCR signalling and fate. Although the use of peptidase inhibitors has already brought success in the treatment of diseases such as hypertension, the discovery of new regulatory mechanisms involving proteolysis that control GPCRs may provide additional targets to modulate dysregulated GPCR signalling in disease.
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Affiliation(s)
- G S Cottrell
- Reading School of Pharmacy, University of Reading, Reading, UK.
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11
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Targeting proteinase-activated receptors: therapeutic potential and challenges. Nat Rev Drug Discov 2012; 11:69-86. [PMID: 22212680 DOI: 10.1038/nrd3615] [Citation(s) in RCA: 240] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Proteinase-activated receptors (PARs), a family of four seven-transmembrane G protein-coupled receptors, act as targets for signalling by various proteolytic enzymes. PARs are characterized by a unique activation mechanism involving the proteolytic unmasking of a tethered ligand that stimulates the receptor. Given the emerging roles of these receptors in cancer as well as in disorders of the cardiovascular, musculoskeletal, gastrointestinal, respiratory and central nervous system, PARs have become attractive targets for the development of novel therapeutics. In this Review we summarize the mechanisms by which PARs modulate cell function and the roles they can have in physiology and diseases. Furthermore, we provide an overview of possible strategies for developing PAR antagonists.
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Maloberti PM, Duarte AB, Orlando UD, Pasqualini ME, Solano ÁR, López-Otín C, Podestá EJ. Functional interaction between acyl-CoA synthetase 4, lipooxygenases and cyclooxygenase-2 in the aggressive phenotype of breast cancer cells. PLoS One 2010; 5:e15540. [PMID: 21085606 PMCID: PMC2978721 DOI: 10.1371/journal.pone.0015540] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 10/22/2010] [Indexed: 12/13/2022] Open
Abstract
The acyl-CoA synthetase 4 (ACSL4) is increased in breast cancer, colon and hepatocellular carcinoma. ACSL4 mainly esterifies arachidonic acid (AA) into arachidonoyl-CoA, reducing free AA intracellular levels, which is in contradiction with the need for AA metabolites in tumorigenesis. Therefore, the causal role of ACSL4 is still not established. This study was undertaken to determine the role of ACSL4 in AA metabolic pathway in breast cancer cells. The first novel finding is that ACSL4 regulates the expression of cyclooxygenase-2 (COX-2) and the production of prostaglandin in MDA-MB-231 cells. We also found that ACSL4 is significantly up-regulated in the highly aggressive MDA-MB-231 breast cancer cells. In terms of its overexpression and inhibition, ACSL4 plays a causal role in the control of the aggressive phenotype. These results were confirmed by the increase in the aggressive behaviour of MCF-7 cells stably transfected with a Tet-off ACSL4 vector. Concomitantly, another significant finding was that intramitochondrial AA levels are significantly higher in the aggressive cells. Thus, the esterification of AA by ACSL4 compartmentalizes the release of AA in mitochondria, a mechanism that serves to drive the specific lipooxygenase metabolization of the fatty acid. To our knowledge, this is the first report that ACSL4 expression controls both lipooxygenase and cyclooxygenase metabolism of AA. Thus, this functional interaction represents an integrated system that regulates the proliferating and metastatic potential of cancer cells. Therefore, the development of combinatory therapies that profit from the ACSL4, lipooxygenase and COX-2 synergistic action may allow for lower medication doses and avoidance of side effects.
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Affiliation(s)
- Paula M. Maloberti
- Instituto de Investigaciones Moleculares de Enfermedades Hormonales Neurodegenerativas y Oncológicas (IIMHNO), Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Alejandra B. Duarte
- Instituto de Investigaciones Moleculares de Enfermedades Hormonales Neurodegenerativas y Oncológicas (IIMHNO), Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Ulises D. Orlando
- Instituto de Investigaciones Moleculares de Enfermedades Hormonales Neurodegenerativas y Oncológicas (IIMHNO), Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - María E. Pasqualini
- Instituto de Biología Celular, School of Medicine, Córdoba National University, Córdoba, Argentina
| | - Ángela R. Solano
- Instituto de Investigaciones Moleculares de Enfermedades Hormonales Neurodegenerativas y Oncológicas (IIMHNO), Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
| | - Carlos López-Otín
- Instituto Universitario de Oncología, Department of Biochemistry and Molecular Biology, Oviedo University, Oviedo, España
| | - Ernesto J. Podestá
- Instituto de Investigaciones Moleculares de Enfermedades Hormonales Neurodegenerativas y Oncológicas (IIMHNO), Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
- * E-mail:
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Rubin H. Contact Interactions Between Cells That Suppress Neoplastic Development: Can They Also Explain Metastatic Dormancy? Adv Cancer Res 2008; 100:159-202. [DOI: 10.1016/s0065-230x(08)00006-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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14
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Abstract
Ordered heterogeneity was introduced as a basic feature of the living state in the mid-1950s. It was later expanded to "order in the large over heterogeneity in the small" as the first principle of a theory of organisms. Several examples of ordered heterogeneity were given at the time to illustrate the principle, but many more have become apparent since then to confirm its generality. They include minimum size requirements for progressive embryological development, the errant behavior of cells liberated from tissue architecture, their sorting out to reconstitute tissues on reaggregation, and contact regulation of cell proliferation. There is increasing heterogeneity of cell growth with age, and marked heterogeneity of many characters among cells of solid epithelial tumors. Normal growth behavior is reintroduced in solitary, carcinogen-initiated epidermal cells by contact with an excess of normal epidermal cells. Contact normalization also occurs when solitary hepatocarcinoma cells are transplanted into the parenchyma of normal liver of young, but not of old, animals. The role of the plasma membrane and adhesion molecules in ordering heterogeneity is evaluated. Organizing the results in a conceptual structure helps to understand classical observations of tumor biology such as the lifetime quiescence of carcinogen-initiated epidermal cells and the marked increase of cancer incidence with age. The principle of order above heterogeneity thus provides a unifying framework for a variety of seemingly unrelated processes in normal and neoplastic development. Whereas contact between cells is required for these processes to occur, gap junctional communication is not required.
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Affiliation(s)
- Harry Rubin
- Department of Molecular and Cell Biology, Life Sciences Addition, University of California, Berkeley, California 94720, USA
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15
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Darmoul D, Marie JC, Devaud H, Gratio V, Laburthe M. Initiation of human colon cancer cell proliferation by trypsin acting at protease-activated receptor-2. Br J Cancer 2001; 85:772-9. [PMID: 11531266 PMCID: PMC2364111 DOI: 10.1054/bjoc.2001.1976] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The protease-activated receptor-2 (PAR-2) is a G protein-coupled receptor that is cleaved and activated by trypsin. We investigated the expression of PAR-2 and the role of trypsin in cell proliferation in human colon cancer cell lines. A total of 10 cell lines were tested for expression of PAR-2 mRNA by Northern blot and RT-PCR. PAR-2 protein was detected by immunofluorescence. Trypsin and the peptide agonist SLIGKV (AP2) were tested for their ability to induce calcium mobilization and to promote cell proliferation on serum-deprived cells. PAR-2 mRNA was detected by Northern blot analysis in 6 out of 10 cell lines [HT-29, Cl.19A, Caco-2, SW480, HCT-8 and T84]. Other cell lines expressed low levels of transcripts, which were detected only by RT-PCR. Further results were obtained with HT-29 cells: (1) PAR-2 protein is expressed at the cell surface; (2) an increase in intracellular calcium concentration was observed upon trypsin (1-100 nM) or AP2 (10-100 microM) challenges; (3) cells grown in serum-deprived media supplemented with trypsin (0.1-1 nM) or AP2 (1-300 microM) exhibited important mitogenic responses (3-fold increase of cell number). Proliferative effects of trypsin or AP2 were also observed in other cell lines expressing PAR-2. These data show that subnanomolar concentrations of trypsin, acting at PAR-2, promoted the proliferation of human colon cancer cells. The results of this study indicate that trypsin could be considered as a growth factor and unravel a new mechanism whereby serine proteases control colon tumours.
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Affiliation(s)
- D Darmoul
- Neuroendocrinologie et Biologie Cellulaire Digestives, Institut National de la Santé et de la Recherche Médicale, INSERM U410, Faculté de Médecine Xavier Bichât, Paris, 75018, France
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16
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Pyrenomycetes and Loculoascomycetes as sources of secondary metabolites. J Ind Microbiol Biotechnol 1996. [DOI: 10.1007/bf01574771] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Wen CM, Kou GH, Chen SN. Cultivation of cells from the heart of the hard clam,Meretrix lusoria (Röding). ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf02388265] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hsuan JJ, Downward J, Clark S, Waterfield MD. Proteolytic generation of constitutive tyrosine kinase activity of the human insulin receptor. Biochem J 1989; 259:519-27. [PMID: 2719663 PMCID: PMC1138539 DOI: 10.1042/bj2590519] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Structural modification induced by partial digestion with trypsin has been shown to stimulate the tyrosine kinase activity of the insulin receptor both in solution and in intact cells [Tamura, Fujita-Yamaguchi & Larner (1983) J. Biol. Chem. 258, 14749-14752; Goren, White & Kahn (1987) Biochemistry 26, 2374-2382; Leef & Larner (1987) J. Biol. Chem. 262, 14837-14842]. Furthermore, experiments involving deletion of sequences encoding the extracellular domain of the insulin receptor suggest that it may function as a protooncogene in fibroblasts [Wang et al., (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 5725-5729]. To further understand the structural requirements that generate this activity, the major activated fragments generated in solution following trypsin digestion have been characterized here, one of which is shown to have a similar amino acid sequence to a transforming protein. Furthermore, treatment with trypsin of intact Chinese hamster ovary cells that overexpress the human insulin receptor stimulates both autophosphorylation of the receptor and 2-deoxyglucose uptake into the cells, but does not enhance receptor internalization. Unlike digestion in solution, no proteolysis or loss of activity of the activated insulin receptor beta-subunit could be detected using intact cells, even at high trypsin concentrations, despite the existence of extracellular sites that are readily cleaved by trypsin in the solubilized receptor. These studies provide further detail of a mechanism used during trypsinization of cells in culture which mimics activation of the insulin receptor and contributes to stimulation of growth.
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Affiliation(s)
- J J Hsuan
- Ludwig Institute for Cancer Research, Middlesex Hospital/University College Branch, London U.K
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19
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el-Achkar P, Langley OK, Mersel M. Effect of cell surface trypsinization on ethanolamine base exchange enzymatic activity of astrocyte primary cultures and derived spontaneously transformed cell lines. Biochem Biophys Res Commun 1989; 159:1055-64. [PMID: 2539135 DOI: 10.1016/0006-291x(89)92216-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Trypsinization of neonatal rat astrocyte primary cultures (normal cells) inhibited the activity of ethanolamine base exchange enzyme (EBEE) by 80%, whereas ethanolamine phosphotransferase (EPT) and choline base exchange (CBEE) enzymatic activities were not affected; subcellular fractionation demonstrated that trypsin treatment affected the intracellular EBEE activity. During trypsinization the enzyme was not taken up by cultured astrocytes but the cell surface was affected. In contrast, the same treatment did not alter EPT, CBEE and EBEE activities of spontaneously transformed cell lines derived from the primary cultures. However, treatment of the transformed cells with db-cAMP prior to trypsin, restored the pattern found in the primary culture, i.e. only EBEE activity was affected. These data suggest that a relationship exists between cell surface organization and intracellular EBEE activity in a culture system which possesses the property to control its own cell division or/and differentiation.
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Affiliation(s)
- P el-Achkar
- Centre de Neurochimie du CNRS, Unité 44 de l'INSERM, Strasbourg, France
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20
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Slosberg EA, Scher BM, Scher W, Josephson S, Waxman S. Induction of differentiation in mouse erythroleukaemia cells by the action of papain at the cell surface. CELL AND TISSUE KINETICS 1987; 20:571-81. [PMID: 3502927 DOI: 10.1111/j.1365-2184.1987.tb01366.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The addition of one of several proteases to cultures of mouse erythroleukaemia (MEL) or human K-562 leukaemia cells can induce a substantial portion of the cells to undergo erythroid differentiation. This effect is due, at least in part, to the proteolytic action of these enzymes. The critical substrate(s) for this proteolytic action is not a component of the medium or a long-lived substance(s) released from the cells. In order to determine if the substrate(s) is located on the cell surface or intracellularly, a comparison of the ability of non-immobilized papain and immobilized papain (i.e. covalently linked to Sepharose beads which were larger than the cells) to induce MEL cell differentiation was undertaken. Both papain preparations induced the same level of differentiation. The proteolytic activity of the bead-linked papain remained associated with the beads. Therefore, proteases induce erythroid differentiation in these cells by acting proteolytically on a substrate(s) that is exterior to the cell.
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Affiliation(s)
- E A Slosberg
- Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
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21
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Abstract
It is clear that there are a number of different types of reactions between thrombin and the cell surface (TABLE 6). In one type, thrombin binds to cell-surface receptors resulting in cellular activation. In other types of reactions, there are at least two components to the thrombin-specific pathway of cellular activation: a classical receptor to which thrombin binds, and a protein that is cleaved. In both types of reactions, thrombin binding and/or proteolysis is linked to changes in GTP-binding proteins, protein kinase C, or other pathways. In most cases, the receptor and membrane substrates involved in cellular activation are not well characterized. In another type of reaction, the interaction between thrombin and proteins in the extracellular fluid is regulated by cell-surface receptors. Binding of thrombin to these receptors can result in acceleration or inhibition of the reactions with the soluble proteins. In the fourth type of reaction, thrombin cleaves a cell-membrane protein that is involved in reactions with plasma proteins. Recognition of the different types of interactions between thrombin and the cell surface is necessary for the correct interpretation of experimental observations. Although the term receptor has classically referred to a cell-surface component to which an agonist binds, it is now clear that there are additional membrane components that specifically bind potential agonists not leading to cellular activation.
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22
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Riederer-Henderson MA. Phenotypic switching to long cilia effected by various proteases: results with Dendraster excentricus and Stronglyocentrotus purpuratus blastulae. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1986; 240:327-33. [PMID: 3641879 DOI: 10.1002/jez.1402400306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Incubation in trypsin effects a phenotypic switch from short to long cilia (greater than 30 micron) in hatched blastulae of the sea urchin, Arbacia punctulata. To determine how trypsin causes such a switch we tested whether the phenomenon was unique to the species, Arbacia, and to the protease, trypsin. With two other echinoderm species, the sand dollar, Dendraster excentricus, and the sea urchin, Strongylocentrotus purpuratus, trypsin incubation increased the percentage of long cilia. During incubation of D. excentricus in trypsin, the percentage of long cilia increased progressively from the normal 10% long cilia of the apical tuft to 45-50% long cilia covering 1/2-3/4 of the embryo. With S. purpuratus blastulae, however, the percentage of long cilia was lower (32-40%) and the results were more variable. Of the additional proteases tested with D. excentricus, elastase was more effective than trypsin in terms of the percentage of long cilia (58%), the mean length, and the broad distribution of lengths formed. Thermolysin was about as effective as trypsin but chymotrypsin was much less so. Thus, increases in ciliary length were not unique to a particular echinoderm species or to incubation in trypsin. The magnitude of the change in length distribution, however, was species- and enzyme-dependent. An extracellular or membrane component with differential susceptibility to various proteases may, therefore, be involved in altering ciliary length.
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23
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Helm BA, Gunn JM. The effect of insulinomimetic agents on protein degradation in H35 hepatoma cells. Mol Cell Biochem 1986; 71:159-66. [PMID: 3534545 DOI: 10.1007/bf00214775] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A wide variety of agents are shown to mimic insulin action and inhibit rates of intracellular protein degradation in H35 hepatoma cells. For oxidizing agents such as NaNO2, H2O2 and oxidized glutathione, inhibition of protein breakdown is reversed by adding catalase. Phenylhydrazine behaves like an oxidant and mimics insulin action in a manner potentiated by superoxide dismutase and reversed by catalase. Similarly the effect of insulin itself is increased by superoxide dismutase and reduced by catalase. Sulfhydryl reagents also mimic insulin action: inhibition of protein breakdown is seen following addition of 2-mercaptoethanol or a brief pre-treatment with N-ethylmaleimide or iodoacetate. Mild pre-treatment with trypsin also inhibits subsequent rates of protein breakdown. A model is proposed suggesting that these insulinomimetic actions involve a common mechanism which links the generation of active oxygen species through the redox potential of the cell to the activation of a proteinase.
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24
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Sullivan LM, Quigley JP. An anticatalytic monoclonal antibody to avian plasminogen activator: its effect on behavior of RSV-transformed chick fibroblasts. Cell 1986; 45:905-15. [PMID: 3011282 DOI: 10.1016/0092-8674(86)90565-9] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A monoclonal antibody has been raised against the serine protease, plasminogen activator (PA) produced by Rous sarcoma virus-transformed chick embryo fibroblasts (RSVCEF), and selected for its ability to inhibit the catalytic activity of PA. The high specificity and anticatalytic nature of the antibody has allowed probing of the direct role of PA in cellular behavior. Microgram quantities of monoclonal IgG inhibit the overgrowth and the morphological changes associated with RSVCEF transformation and the degradation of extracellular matrix mediated by RSVCEF, indicating a catalytic role for PA in these cellular processes. Specific cleavage of extracellular matrix proteins by immunoaffinity-purified PA in the complete absence of plasminogen demonstrates a direct catalytic involvement of PA in matrix degradation.
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25
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Studies of the role of a particulate folate-binding protein in the uptake of 5-methyltetrahydrofolate by cultured human KB cells. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(18)95679-6] [Citation(s) in RCA: 111] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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26
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Schubert D, LaCorbiere M. Isolation of an adhesion-mediating protein from chick neural retina adherons. J Cell Biol 1985; 101:1071-7. [PMID: 2993313 PMCID: PMC2113697 DOI: 10.1083/jcb.101.3.1071] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Adherons are high molecular weight glycoprotein complexes which are released into the growth medium of cultured cells. They mediate the adhesive interactions of many cell types, including those of embryonic chick neural retina. The cell surface receptor for chick neural retina adherons has been purified, and shown to be a heparan sulfate proteoglycan (Schubert, D., and M. LaCorbiere, 1985, J. Cell Biol., 100:56-63). This paper describes the isolation and characterization of a protein in neural retina adherons which interacts specifically with the cell surface receptor. The 20,000-mol-wt protein, called retinal purpurin (RP), stimulates neural retina cell-substratum adhesion and prolongs the survival of neural retina cells in culture. The RP protein interacts with heparin and heparan sulfate, but not with other glycosaminoglycans. Monovalent antibodies against RP inhibit RP-cell adhesion as well as adheron-cell interactions. The RP protein is found in neural retina, but not in other tissues such as brain and muscle. These data suggest that RP plays a role in both the survival and adhesive interactions of neural retina cells.
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27
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Diverse mitogenic agents induce the phosphorylation of two related 42,000-dalton proteins on tyrosine in quiescent chick cells. Mol Cell Biol 1984. [PMID: 6199661 DOI: 10.1128/mcb.4.1.30] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Incubation of quiescent chicken embryo cells with platelet-derived growth factor, epidermal growth factor, or serum was found to stimulate phosphorylation of two proteins of ca. 42,000 daltons on tyrosine. These proteins are structurally related to each other and to two proteins phosphorylated on tyrosine under similar conditions in mitogen-treated mouse fibroblasts. Three other very different mitogenic agents, the protease trypsin and the chemically unrelated tumor promoters 12-O-tetradecanoyl-phorbol-13-acetate and teleocidin, stimulated phosphorylation of the same proteins. In all cases, phosphotyrosine was detected in these phosphoproteins. Although additional changes in protein phosphorylation were evident, no other proteins were observed by two-dimensional gel electrophoresis which contained increased amounts of phosphotyrosine in mitogen-treated chicken embryo cells. One of these 42,000-dalton proteins was shown previously to be phosphorylated on tyrosine in chicken embryo cells transformed with various retroviruses whose transforming proteins possess tyrosine protein kinase activity. Phosphorylation of the 42,000-dalton proteins could be important in the regulation of cell division.
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28
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Cooper JA, Sefton BM, Hunter T. Diverse mitogenic agents induce the phosphorylation of two related 42,000-dalton proteins on tyrosine in quiescent chick cells. Mol Cell Biol 1984; 4:30-7. [PMID: 6199661 PMCID: PMC368654 DOI: 10.1128/mcb.4.1.30-37.1984] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Incubation of quiescent chicken embryo cells with platelet-derived growth factor, epidermal growth factor, or serum was found to stimulate phosphorylation of two proteins of ca. 42,000 daltons on tyrosine. These proteins are structurally related to each other and to two proteins phosphorylated on tyrosine under similar conditions in mitogen-treated mouse fibroblasts. Three other very different mitogenic agents, the protease trypsin and the chemically unrelated tumor promoters 12-O-tetradecanoyl-phorbol-13-acetate and teleocidin, stimulated phosphorylation of the same proteins. In all cases, phosphotyrosine was detected in these phosphoproteins. Although additional changes in protein phosphorylation were evident, no other proteins were observed by two-dimensional gel electrophoresis which contained increased amounts of phosphotyrosine in mitogen-treated chicken embryo cells. One of these 42,000-dalton proteins was shown previously to be phosphorylated on tyrosine in chicken embryo cells transformed with various retroviruses whose transforming proteins possess tyrosine protein kinase activity. Phosphorylation of the 42,000-dalton proteins could be important in the regulation of cell division.
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29
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Abstract
A number of studies over the past decade (reviewed in refs 1-3) have suggested an intimate link between fibronectin, proteolysis and the control of cell proliferation. So far, however, no unequivocal connection has been made. Recent evidence that gelatin-binding fragments of fibronectin enhance morphological cell transformation led to the postulate that the fibronectin molecule harbours latent properties released only on proteolysis. These findings led us to investigate the role of fibronectin fragmentation in the regulation of cell growth in vitro, and we report here that whilst fibronectin is without effect, its cathepsin D digests possess the ability to initiate DNA synthesis in serum-deprived quiescent cultures of normal hamster fibroblasts.
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30
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Mersel M, Benenson A, Delaunoy JP, Devilliers G, Mandel P. Long-term effects of brain trypsinization before cell seeding on cell morphology and surface composition. Neurochem Res 1983; 8:449-63. [PMID: 6888647 DOI: 10.1007/bf00965101] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The relation between the pattern of proteins localized in the surface of astroglial cells and cell differentiation was investigated in primary cultures derived from neonatal rat brains, dissociated either mechanically (MDC) or by 3 (TDC3) and 30 minutes (TDC30) trypsinization. Morphological and ultrastructural studies revealed a bed layer composed of flat, polygonal young and differentiated astrocytes in all types of cultures and a surface layer composed of small, ovoide undifferentiated cells which were more numerous in TDC30 than in TDC3 and MDC. The enrichment in undifferentiated cells, induced by prolonged brain trypsinization prior cell seeding, was observed during two weeks in culture; latter, by day 20, the cell population in all cultures was that of differentiated astrocytes. The presence of structural and enzymatic cell markers indicated that the cell population in MDC and TDC3 as well as in TDC3, including the small cells, was of astroglial origin. Concomitant with the morphological changes, cells in TDC30 were less accessible to surface labeling than those composing MDC. Subsequent electrophoresis of the labeled surface proteins demonstrated that a 140-130 K complex was the most "sensible" to brain trypsinization and that their accessibility to the surface probing was maximal during the differentiation of astrocytes in MDC or of small cells in TDC30. By day 20, these components were not significantly labeled in both, MDC, and TDC30, cultures. The use of two types of astrocytes primary culture which were different in the ratio of differentiated to undifferentiated cells and their surface labeling at different growth stages showed a variation in the composition of surface proteins during the cell maturation. The increased accessibility of some surface proteins to external probing when the cells developed to differentiated astrocytes might suggest their involvement in cell differentiation.
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31
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Scott RE, Yun K, Florine DL. Differential mitogenic effects of methyl isobutyl xanthine and a tumor growth factor on G1-arrested 3T3 T proadipocytes at the predifferentiation GD state and the growth-factor deficiency GS state. Exp Cell Res 1983; 143:405-14. [PMID: 6187588 DOI: 10.1016/0014-4827(83)90067-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Two growth-states exist in the G1 phase of the 3T3 T proadipocyte cell cycle. GD is the arrest state at which proadipocytes must growth-arrest prior to differentiation. GS is the arrest state at which proadipocytes growth-arrest following deprivation of serum or growth factors. In an attempt to further distinguish these arrest states, we have compared the relative ability of a variety of mitogens to induce GD- and GS-arrested cells to initiate DNA synthesis. The data show that GD-arrested cells at both high and low densities can be induced to proliferate by methyl-isobutyl-xanthine (MIX), whereas high and low density GS-arrested cells are not. The data also show that a tumor growth factor can stimulate the proliferation of both high and low density GD- and GS-arrested cells, whereas other agents are poor mitogens for high density GD-arrested cells. We conclude that MIX and a tumor growth factor (TUGF) can serve as probes to study the characteristics of the GD arrest state.
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32
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Sharefkin JB, Latker CH, D'Amore PA, Trinidad-Vasquez M, Rich NM. Seeding of Dacron vascular prostheses with endothelium of aortic origin. J Surg Res 1983; 34:33-43. [PMID: 6218342 DOI: 10.1016/0022-4804(83)90019-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Seeding of autologous venous endothelium on Dacron vascular prostheses in dogs results in endothelial coverage of the prosthetic flow surface 4-6 weeks after implantation. Canine aortic endothelium, in contrast, usually fails to completely cover an unseeded prosthesis by pannus ingrowth even over much longer periods. To see if the success of endothelial seeding stems from a difference in the ability of venous and aortic endothelium to grow on prosthetic surfaces, we seeded freshly harvested autologous aortic endothelium on Dacron velour infrarenal aortic prostheses in dogs. Six weeks after surgery these prostheses showed the features reported to be typical of seeded prostheses. Scanning electron micrographs showed a luminal lining of flat polygonal cells without fibrin or adherent formed blood elements, and light microscopy showed an underlying layer containing aligned spindle-shaped cells with elongated nuclei and cell-lined subluminal channels. Control prostheses were covered with fibrin and platelet-rich thrombi everywhere except for limited pannus ingrowth at anastomotic sites. The results suggest that the success of autologous endothelial seeding cannot be ascribed to inherent differences in properties such as mitotic capacity or fibrinolysis between venous and aortic endothelium. The formation of complete endothelial linings by seeding must instead result from a more favorable condition for endothelial cell growth created by the cell harvesting or seeding process itself.
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33
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Chernavskii DS, Polezhaev AA, Volkov EI. Cell surface and cell division. CELL BIOPHYSICS 1982; 4:143-61. [PMID: 6181881 DOI: 10.1007/bf02918310] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A mathematical model of the regulation of cell division is suggested. The model is based on the hypothesis that the process giving rhythm to cell division is located in the cell membrane: i.e., the process of free-radical oxidation of membrane lipids. Much depends on the physical state of the membrane. In the membrane, phase transitions take place because of the changes in lipid composition. These transitions differ in normal and tumor cells: in normal cells they are sharp and hysteretic owing to the presence of a framework (membrane skeleton) on the surface of the membrane, while in tumor cells the integrity of the surface is violated so that the transitions are smooth. This model makes it possible to explain differences in the regulation of normal and cancer cell proliferation. Within the limits of the model, such phenomena as density dependent inhibition of growth, reverse transformation, influence of cyclic AMP and ions of Ca2+ on the cell cycle, the actions of serum and of proteases on the cycle, and so on, are explained. A rational scheme for the appearance of the selective damage found in tumor cells is proposed.
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34
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Kalderon N. Role of the plasmin-generating system in the developing nervous tissue: I. Proteolysis as a mitogenic signal for the glial cells. J Neurosci Res 1982; 8:509-19. [PMID: 6218310 DOI: 10.1002/jnr.490080237] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The role of the plasmin-generating system, a serum component, in the development of dissociated embryonic chick spinal cord cells in culture was studied. Studies were performed in a defined system where the cells were maintained in a serum-free medium. Under these conditions the cells produce plasminogen activator. It was found that plasminogen, when added to the chemically defined culture medium at concentrations of 0.2-0.75 microgram/ml, stimulates [3H]thymidine uptake (as expressed per total DNA) in a dose-response manner. This mitogenic effect is abolished by the protease inhibitors leupeptin and aprotinin. Trypsin, but not chymotrypsin, can produce similar effects. It is concluded that plasmin, which is produced as a result of the activation of plasminogen, is a component that serves as a proliferation factor in developing spinal cords in culture.
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35
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Miskin R, Soreq H. Sensitive autoradiographic quantification of electrophoretically separated proteases. Anal Biochem 1981; 118:252-8. [PMID: 7039411 DOI: 10.1016/0003-2697(81)90187-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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36
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Fulton RJ, Hart DA. Characterization of a plasma membrane-associated plasminogen activator on thymocytes. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 642:345-64. [PMID: 6793069 DOI: 10.1016/0005-2736(81)90451-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Plasma membranes isolated from normal thymocytes of hamster and rats were found to exhibit neutral protease activity toward 125I-labeled casein. The plasma membrane-associated proteases were completely inhibited by the serine protease inhibitors, diisopropyl fluorophosphate, phenylmethylsulfonyl fluoride and p-nitrophenyl-p-guanidinobenzoate, partially inhibited by soybean trypsin inhibitor and antipain, but were only weakly inhibited by L-1-tosylamino-2-phenylethyl chloromethyl ketone. The plasma membrane-associated proteases were also completely inhibited by ZnCl2 (75--100 mu M), but they were not affected by several other divalent cations. The plasma membrane fraction contained a plasminogen activator activity which was specifically localized in this fraction. The plasma membrane-associated plasminogen activator activity was inhibited by all of the inhibitors which inhibited plasma membrane-associated proteases except L-1-tosylamido-2-phenylethyl chloromethyl ketone. Labeling of plasma membrane-associated serine esterases with [3H] diisopropyl fluorophosphate followed by separation of the proteins by sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that this fraction contained a single major 3H-labeled protein of Mr 105 000. Both the plasminogen activator and the Mr 105 000 esterase were shown to be glycoproteins by affinity chromatography on lentil lectin-Sepharose. These results indicate that the plasminogen activator of thymocytes is a glycosylated serine protease with an active site-containing subunit of Mr 105 000 which is specifically localized in the plasma membrane.
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37
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Hubbard JR, Liberti JP. Enhancement of cartilage protease activity during age and growth hormone-dependent growth. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 673:332-8. [PMID: 7013819 DOI: 10.1016/0304-4165(81)90464-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We wish to report an intriguing relationship between cartilage protease activity and rat growth rate. This was demonstrated by comparing protease activities of rats having different growth rates, i.e., normal rats of different ages, hypophysectomized and growth hormone-treated hypophysectomized rats. Protease activity, assessed by hydrolysis of a gelatin film by cartilage microtome slices, at pH 4.0, was time and temperature dependent. Preincubation of cartilage tissue at various temperatures resulted in an increase of protease activity from 4 degrees C to 37 degrees C and a decrease in activity from 37 degrees C to 100 degrees C. The activity of younger (4 week old) more rapidly growing rats, was greater than that of older, less rapidly growing animals. Hypophysectomy reduced protease activity to approximately one-third normal levels. However, injection of bovine growth hormone into hypophysectomized rats restored the activity. These results suggest that a positive correlation exists between cartilage protease activity and growth rate. Our results support the novel hypothesis that cartilage growth could be mediated, at least in part, via growth hormone-dependent proteolytic activity.
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38
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Crossin KL, Carney DH. Evidence that microtubule depolymerization early in the cell cycle is sufficient to initiate DNA synthesis. Cell 1981; 23:61-71. [PMID: 6111398 DOI: 10.1016/0092-8674(81)90270-1] [Citation(s) in RCA: 173] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Microtubule disrupting drugs initiated DNA synthesis in serum-free cultures of nonproliferating fibroblast-like cells. The addition of colchicine to chick, mouse and human fibroblasts in serum-free medium stimulated thymidine incorporation at least twofold, with a half-maximal concentration of 1 X 10(-7) M. This stimulation represented up to 75% of the maximal stimulation by thrombin and was paralleled by an increase in the percentage of labeled nuclei. Other microtubule disrupting drugs showed similar stimulation, whereas lumicolchicine had no effect. Indirect immunofluorescent staining of tubulin showed a correlation between microtubule depolymerization and initiation of DNA synthesis by these drugs. A 2 hr treatment with 10(-6) M colchicine caused complete disruption of the microtubular network and stimulated thymidine incorporation (measured 28 hr later) to an even greater extent than continuous colchicine exposure. A similar 2 hr exposure to 10(-6) M colcemid also stimulated thymidine incorporation and led to a 50% increase in cell number. Taxol, a drug which stabilizes cytoplasmic microtubules, blocks initiation of DNA synthesis by colchicine, indicating that microtubule depolymerization is necessary for this initiation. To determine if microtubule depolymerization is involved in stimulation of DNA synthesis by other growth factors, highly purified human thrombin was added to cells with or without colchicine. In no case did colchicine plus thrombin increase DNA synthesis above that of the maximal stimulation by thrombin alone. Furthermore, pretreatment of cultures with taxol (5 micrograms/ml) inhibited approximately 30% of the stimulation of thymidine incorporation by thrombin. Together, these studies demonstrate that microtubule depolymerization is sufficient to initiate both DNA synthesis and events leading to cell division and suggest that microtubule depolymerization may be a required step in initiation of cell proliferation by growth factors such as highly purified human thrombin.
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39
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Hochhauser SJ, Stein JL, Stein GS. Gene expression and cell cycle regulation. INTERNATIONAL REVIEW OF CYTOLOGY 1981; 71:95-243. [PMID: 6165699 DOI: 10.1016/s0074-7696(08)61183-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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40
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41
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Salzer JL, Bunge RP. Studies of Schwann cell proliferation. I. An analysis in tissue culture of proliferation during development, Wallerian degeneration, and direct injury. J Cell Biol 1980; 84:739-52. [PMID: 6244318 PMCID: PMC2110577 DOI: 10.1083/jcb.84.3.739] [Citation(s) in RCA: 346] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In this paper the stimuli for and pattern of Schwann cell proliferation are defined under various experimental conditions. We used a tissue culture system in which fetal rat dorsal root ganglia, treated to eliminate contaminating fibroblasts (Wood, P., 1976, Brain Res. 115:361--375), appear to recapitulate many aspects of the developing peripheral nervous system. We observed that: (a) proliferation of Schwann cells on neurites is initially rapid, but, as each neurite becomes fully ensheathed, division slows considerably and is confined to the periphery of the outgrowth; (b) during the period of rapid proliferation, excision of the ganglion causes a rapid decay in the number of dividing cells; (c) excision of the ganglion from more established cultures in which there was little ongoing proliferation resulted in a small increase in labeling at the site of excision for all Schwann cells and a substantial increase in labeling for myelin-related cells with a peak labeling period at 4 d; (d) direct mechanical injury during Wallerian degeneration is mitogenic for Schwann cells; (e) a variety of potential mitogens failed to stimulate Schwann cell proliferation, and (f) replated cells have a slightly higher level of proliferation and show a small and variable response to the addition of cAMP.
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Verger C. Proliferation and morphology of chick embryo cells cultured in the presence of horse serum and hemoglobin. IN VITRO 1979; 15:587-92. [PMID: 511207 DOI: 10.1007/bf02623394] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We have shown previously that hemoglobin greatly stimulates chick embryo cell proliferation in Eagle's minimal essential medium supplemented with horse serum. In the present study we compared the effects of horse serum plus 10 micrometers hemoglobin to those of fetal bovine serum on subcultures of chick embryo cells serially propagated at high cell densities. The cells became elongated in the presence of fetal bovine serum and their rate of proliferation progressively decreased, whereas they became polygonal in the presence of horse serum plus hemoglobin and proliferated well in successive cell passages. The polygonal cells obtained in the presence of horse serum plus hemoglobin rapidly elongated if cultured at low cell densities in the presence of fetal bovine serum, but, in contrast, elongated cells did not yield polygonal cells if cultured at low densities in the presence of horse serum plus hemoglobin. It is possible that the polygonal and elongated cells are undifferentiated cells and differentiating myogenic cells, respectively.
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Abstract
Proteolytic activities were measured in extracts of human skin melanoma, lymphatic metastasis and in nonmalignant naevi by using various proteinase substrates as well as plasminogen activator assay. pH-optima for hydrolysis of various proteinase substrates by these tumors were found to be essentially the same as in healthy human skin. Melanoma extracts were found to especially readily hydrolyze N-alpha-benzoyl-DL-arginine beta-naphthylamine (BANA) at pH 5.8 in the presence of 1 mmol/l dithiothreitol and EDTA (cathepsin B1-like enzyme) as well as histones and p-tosyl-L-arginine methyl ester (TAME) at pH 7.5, and showed increased capacity to activate plasminogen when compared to nonmalignant naevus. The possible role of proteinases in malignant melanoma is discussed.
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Baumann H, Doyle D. Effect of trypsin on the cell surface proteins of hepatoma tissue culture cells. Characterization of a carbohydrate-rich glycopeptide released from a calcium binding membrane glycoprotein. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)50677-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Glenn KC, Cunningham DD. Thrombin-stimulated cell division involves proteolysis of its cell surface receptor. Nature 1979; 278:711-4. [PMID: 431729 DOI: 10.1038/278711a0] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A cell-surface component of molecular weight 43,000 is cleaved by thrombin on cells that divide after thrombin treatment, but is not cleaved on cells that are unresponsive to its mitogenic action. Studies with a photoreactive derivative of thrombin showed that its cell surface receptor has a molecular weight of 43,000. This indicates that thrombin must cleave its receptor to stimulate cell division.
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Grumm FG, Armstrong PB. Proteases are mitogenic to mesenchyme in vivo. A study using the chick embryo chorioallantoic membrane. Exp Cell Res 1979; 119:317-26. [PMID: 428463 DOI: 10.1016/0014-4827(79)90359-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Cunningham DD, Glenn KC, Baker JB, Simmer RL, Low DA. Mechanisms of thrombin-stimulated cell division. JOURNAL OF SUPRAMOLECULAR STRUCTURE 1979; 11:259-67. [PMID: 548651 DOI: 10.1002/jss.400110215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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48
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Carney DH, Cunningham DD. Role of specific cell surface receptors in thrombin-stimulated cell division. Cell 1978; 15:1341-9. [PMID: 729002 DOI: 10.1016/0092-8674(78)90059-4] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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49
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Rampini C, Dubois C. [32P incorporation into phospholipids of EHSVi transformed fibroblasts, with regard to adherence to the support]. Biochimie 1978; 60:681-4. [PMID: 719046 DOI: 10.1016/s0300-9084(78)80788-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The rate of 32P incorporation into phospholipids of EHSVi transformed fibroblasts was studied by pulse experiments (2 hours) in cells which are detached from the support by trypsin and either maintained in suspension or replated and in the process of adhering. This is performed comparatively to cells in monolayers. Cells are taken during or after the log phase. Both global incorporation into phospholipids and, in the case of cells in log phase, percentage of incorporation into phosphatidylinositol are lowered, after detachment from the support, in suspended cells. They are stimulated by a new contact with the support. In the same conditions, percentages of incorporation into phosphatidylethanolamine and phosphatidylcholine remain at values they have in cells in monolayers. These values are characteristic of the physiological state of cells in monolayers, in relation with medium factors exhaustion.
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Carney DH, Cunningham DD. Cell surface action of thrombin is sufficient to initiate division of chick cells. Cell 1978; 14:811-23. [PMID: 688395 DOI: 10.1016/0092-8674(78)90337-9] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Thrombin covalently linked to carboxylate-modified polystyrene beads initiated division of quiescent chick embryo (CE) cells either in medium containing low levels of serum or in serum-free medium. Release of thrombin was monitored by measuring acid-precipitable radioactivity released from 125I-thrombin beads into the medium during incubation with cells. Even if all of the acid-precipitable material released from the beads were active thrombin, it was not sufficient to account for any of the observed cell division, and was 10-30 fold less than the amount necessary to produce the increase in cell number caused by the thrombin beads. Two other kinds of experiments also showed that material released into the medium did not account for the observed initiation of cell division. First, medium taken from cultures incubated with thrombin beads did not initiate cell division when added to new quiescent cultures. Second, in coverslip experiments where populations of cells with an without thrombin feads shared the same medium, only bead-contacted cells divided. Several results suggested that the material which was released from the thrombin beads resulted from cell-associated proteolysis rather than from "leakage" of intact thrombin from the beads. For example, after incubating 125I-thrombin beads with or without CE cells, we were unable to detect any intact thrombin released into the medium. In addition, most of the material released from the beads was acid-soluble and was only released in the presence of CE cells. A few thrombin beads were endocytosed by CE cells, but they were surrounded by an intact plasma membrane. Thus they did not directly interact with the cytoplasm. The close association of many of the beads with the cell surface and the presence of a few beads in endocytic vesicles made it important to consider the possibility that thrombin might be released from the beads directly into the cells. This possibility was explored using ultrastructural (EM) autoradiography. With this technique (where one grain represented 700--900 thrombin molecules), we found that beads inside the cells had approximately the same number of grains as beads not in contact with cells. This suggested that little, if any, additional radioactive material had been released from the beads which were in contact with the cells. In addition, we were unable to detect any grains in the cytoplasm which could be attributed to released thrombin, even using an amount of 125I-thrombin beads which was 8 fold greater than the amount which produced maximal cell division. Taken together, these results provide direct evidence that thrombin action at the cell surface is sufficient to initiate division of CE cells.
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