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Benay S, Meille C, Kustermann S, Walter I, Walz A, Gonsard PA, Pietilae E, Kratochwil N, Iliadis A, Roth A, Lave T. Model-based assessment of erlotinib effect in vitro measured by real-time cell analysis. J Pharmacokinet Pharmacodyn 2015; 42:275-85. [DOI: 10.1007/s10928-015-9415-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 03/25/2015] [Indexed: 11/30/2022]
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2
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Zheng J, Chen Y, Pat B, Dell’Italia LA, Tillson M, Dillon AR, Powell P, Shi K, Shah N, Denney T, Husain A, Dell’Italia LJ. Microarray identifies extensive downregulation of noncollagen extracellular matrix and profibrotic growth factor genes in chronic isolated mitral regurgitation in the dog. Circulation 2009; 119:2086-95. [PMID: 19349319 PMCID: PMC3092370 DOI: 10.1161/circulationaha.108.826230] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The volume overload of isolated mitral regurgitation (MR) in the dog results in left ventricular (LV) dilatation and interstitial collagen loss. To better understand the mechanism of collagen loss, we performed a gene array and overlaid regulated genes into ingenuity pathway analysis. METHODS AND RESULTS Gene arrays from LV tissue were compared in 4 dogs before and 4 months after MR. Cine-magnetic resonance-derived LV end-diastolic volume increased 2-fold (P=0.005), and LV ejection fraction increased from 41% to 53% (P<0.007). LV interstitial collagen decreased 40% (P<0.05) compared with controls, and replacement collagen was in short strands and in disarray. Ingenuity pathway analysis identified Marfan syndrome, aneurysm formation, LV dilatation, and myocardial infarction, all of which have extracellular matrix protein defects and/or degradation. Matrix metalloproteinase-1 and -9 mRNA increased 5- (P=0.01) and 10-fold (P=0.003), whereas collagen I did not change and collagen III mRNA increased 1.5-fold (P=0.02). However, noncollagen genes important in extracellular matrix structure were significantly downregulated, including decorin, fibulin 1, and fibrillin 1. In addition, connective tissue growth factor and plasminogen activator inhibitor were downregulated, along with multiple genes in the transforming growth factor-beta signaling pathway, resulting in decreased LV transforming growth factor-beta1 activity (P=0.03). CONCLUSIONS LV collagen loss in isolated, compensated MR is chiefly due to posttranslational processing and degradation. The downregulation of multiple noncollagen genes important in global extracellular matrix structure, coupled with decreased expression of multiple profibrotic factors, explains the failure to replace interstitial collagen in the MR heart.
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Affiliation(s)
- Junying Zheng
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
| | - Yuanwen Chen
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
| | - Betty Pat
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
| | - Louis A Dell’Italia
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
| | - Michael Tillson
- Auburn University College of Veterinary Medicine, Auburn, AL
| | - A Ray Dillon
- Auburn University College of Veterinary Medicine, Auburn, AL
| | - Pamela Powell
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
| | - Ke Shi
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
| | - Neil Shah
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
| | | | - Ahsan Husain
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
- Department of Physiology and Biophysics, University of Alabama, Birmingham, AL, Birmingham
| | - Louis J Dell’Italia
- Center for Heart Failure Research, Department of Medicine, University of Alabama, Birmingham, AL, Birmingham
- Department of Veteran Affairs, Auburn, AL
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3
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Webb SE, Roberts SK, Needham SR, Tynan CJ, Rolfe DJ, Winn MD, Clarke DT, Barraclough R, Martin-Fernandez ML. Single-molecule imaging and fluorescence lifetime imaging microscopy show different structures for high- and low-affinity epidermal growth factor receptors in A431 cells. Biophys J 2007; 94:803-19. [PMID: 17890389 PMCID: PMC2186246 DOI: 10.1529/biophysj.107.112623] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Epidermal growth factor (EGF) receptor (EGFR) modulates mitosis and apoptosis through signaling by its high-affinity (HA) and low-affinity (LA) EGF-binding states. The prevailing model of EGFR activation-derived from x-ray crystallography-involves the transition from tethered ectodomain monomers to extended back-to-back dimers and cannot explain these EGFR affinities or their different functions. Here, we use single-molecule Förster resonant energy transfer analysis in combination with ensemble fluorescence lifetime imaging microscopy to investigate the three-dimensional architecture of HA and LA EGFR-EGF complexes in cells by measuring the inter-EGF distances within discrete EGF pairs and the vertical distance from EGF to the plasma membrane. Our results show that EGFR ectodomains form interfaces resulting in two inter-EGF distances ( approximately 8 nm and < 5.5 nm), different from the back-to-back EGFR ectodomain interface ( approximately 11 nm). Distance measurements from EGF to the plasma membrane show that HA EGFR ectodomains are oriented flat on the membrane, whereas LA ectodomains stand proud from it. Their flat orientation confers on HA EGFR ectodomains the exclusive ability to interact via asymmetric interfaces, head-to-head with respect to the EGF-binding site, whereas LA EGFRs must interact only side-by-side. Our results support a structural model in which asymmetric EGFR head-to-head interfaces may be relevant for HA EGFR oligomerization.
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Affiliation(s)
- Stephen E.D. Webb
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - Selene K. Roberts
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - Sarah R. Needham
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - Christopher J. Tynan
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
- Physics Department and Surface Science Research Centre, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Daniel J. Rolfe
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - Martyn D. Winn
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - David T. Clarke
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - Roger Barraclough
- School of Biological Sciences, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Marisa L. Martin-Fernandez
- Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
- Address reprint requests to Marisa L. Martin-Fernandez, STFC Daresbury Laboratory, Warrington WA4 4AD, UK. Tel.: 44-1925-603568; Fax: 44-1925-603124.
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Jia C, Zhou Z, Liu R, Chen S, Xia R. EGF receptor clustering is induced by a 0.4 mT power frequency magnetic field and blocked by the EGF receptor tyrosine kinase inhibitor PD153035. Bioelectromagnetics 2007; 28:197-207. [PMID: 17019730 DOI: 10.1002/bem.20293] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Atomic force microscopy (AFM), transmission electron microscopy (TEM), and confocal laser scanning microscopy were used to investigate the effects of a 50 Hz 0.4 mT magnetic field (MF) on the clustering of purified epidermal growth factor receptors (EGFRs) and EGFRs in Chinese hamster lung (CHL) cell membrane. The results demonstrate that exposing purified EGFRs to the MF for 30 min induces receptor clustering. The peak height of apparent clusters increased from 1.42 +/- 0.18 (sham-exposed) to 3.08 +/- 0.38 nm (exposed) while the mean half-width increased from 21.7 +/- 2.2 to 33.0 +/- 4.0 nm. A similar effect was also observed by TEM. Treatment of purified EGFR with PD153035 (PD), an EGFR-specific tyrosine kinase (TK) inhibitor, inhibited the MF-induced EGFR clustering of the purified proteins, an effect also observed for the receptors in cell membrane in the absence of EGF. These results strongly suggest that the 50 Hz 0.4 mT MF interferes with the EGFR signaling pathway, most likely by interacting with the cytoplasmic TK domain.
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Affiliation(s)
- Caili Jia
- Biophysics Laboratory, Physics Department, East China Normal University, Shanghai, China
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5
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Konishi H, Tashiro K, Murata Y, Nabeshi H, Yamauchi E, Taniguchi H. CFBP Is a Novel Tyrosine-phosphorylated Protein That Might Function as a Regulator of CIN85/CD2AP. J Biol Chem 2006; 281:28919-31. [PMID: 16895919 DOI: 10.1074/jbc.m605693200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
To decipher the global network of the epidermal growth factor (EGF) receptor-mediated signaling pathway, a large scale proteomic analysis of tyrosine-phosphorylated proteins was conducted. Here, we focus on characterizing a novel protein, CFBP (CIN85/CD2AP family binding protein), identified in the study. CFBP was found to be phosphorylated at tyrosine 204 upon EGF stimulation, and the CIN85/CD2AP family was identified as a binding partner. A proline-rich motif of CFBP is recognized by one of the three Src-homology 3 domains of CIN85/CD2AP, and the affinity of the interaction is regulated by the tyrosine phosphorylation of CFBP. They co-localize in actinenriched structures, and overexpression of CFBP induced morphological changes with actin reorganization. Furthermore, CFBP accelerated the EGF receptor's down-regulation by facilitating the recruitment of Cbl to the CD2AP/CIN85 complex. Two spliced variants of CFBP lacking either exon 5 or 8 are also expressed, and the variant lacking exon 5 without the proline-rich motif lacks the ability to bind to the CIN85/CD2AP family. The CFBP protein seems to play a key role in the ligand-mediated internalization and down-regulation of the EGF receptor.
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Affiliation(s)
- Hiroaki Konishi
- Institute for Enzyme Research, University of Tokushima, Tokushima 770-8503, Japan and Harima Institute at SPring-8, RIKEN, Hyogo 679-5148, Japan.
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Martin-Fernandez M, Clarke DT, Tobin MJ, Jones SV, Jones GR. Preformed oligomeric epidermal growth factor receptors undergo an ectodomain structure change during signaling. Biophys J 2002; 82:2415-27. [PMID: 11964230 PMCID: PMC1302032 DOI: 10.1016/s0006-3495(02)75585-9] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Fluorescence resonance energy transfer (FRET) was used to reveal aspects of the mechanism of signal transduction by epidermal growth factor receptors (EGFR). The superpositions of epidermal growth factor (EGF), transforming growth factor-alpha (TGFalpha) and an antibody fragment (29.1) to the carbohydrate extremity of the receptor's ectodomain as measured by FRET, show that 14% of EGFRs in A431 cells are oligomerized before growth factor binding. After binding growth factor and signaling, these oligomers dissociate before releasing growth factor. Time courses of the FRET-derived distances between constitutively oligomerized EGFRs during signal transduction show a transient structural change in the extracellular domain, which occurs simultaneously with the production of intracellular Ca2+ signals. The FRET measurements also show a slow increase in oligomerization of EGFR monomers after growth factor binding. The structural change found in the extracellular domain of oligomeric EGFRs is similar to that shown by others for EPO, Neu, Fas, and tumor necrosis factor receptors, and may therefore be a common property of the transduction of the receptor-mediated signals.
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Kawahara E, Nakada N, Hikichi T, Kobayashi J, Nakanishi I. EGF and beta1 integrin convergently regulate migration of A431 carcinoma cell through MAP kinase activation. Exp Cell Res 2002; 272:84-91. [PMID: 11740868 DOI: 10.1006/excr.2001.5399] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We found that the convergently epidermal growth factor (EGF)-induced signal and the collagen-induced signal activate mitogen-activated protein kinase (MAPK), which induces migration. We examined the signaling mechanisms of EGF-induced cell migration on collagen using the A431 carcinoma cell. EGF (10 ng/ml) induced migration on collagen, but inhibited proliferation. Using a MAPK cascade inhibitor, PD98059, it was shown that EGF-induced migration on collagen was mediated by MAPK whereas EGF-induced migration on fibronectin and vitronectin was not. PD98059 also showed that activation of MAPK induced by EGF enhanced the adhesiveness of A431 cells to collagen. By Western blotting analysis, the kinetics of MAPK phosphorylation induced by EGF and collagen was examined separately, and convergently. First of all, EGF without collagen caused transient MAPK phosphorylation. Collagen without EGF caused MAPK to be immediately and transiently dephosphorylated, and rephosphorylated followed by sustained hyperphosphorylation. EGF together with collagen caused an immediate, and sustained, hyperphosphorylation. These facts suggest that the transient MAPK dephosphorylation induced by collagen is required for migration in order to maintain an appropriate level of sustained phosphorylation. Furthermore, we found that adhesion of A431 cells to collagen was blocked by the anti-beta1 integrin antibody or by the mixed antibodies composed of anti-alpha1, -alpha2, and -alpha3 antibodies, indicating that collagen-induced MAPK phosphorylation was mediated through alpha1beta1, alpha2beta1, and alpha3beta1 integrins.
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Affiliation(s)
- E Kawahara
- Department of Laboratory Sciences, School of Health Sciences, Faculty of Medicine, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 9200942, Japan.
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Lu Z, Jiang G, Blume-Jensen P, Hunter T. Epidermal growth factor-induced tumor cell invasion and metastasis initiated by dephosphorylation and downregulation of focal adhesion kinase. Mol Cell Biol 2001; 21:4016-31. [PMID: 11359909 PMCID: PMC87064 DOI: 10.1128/mcb.21.12.4016-4031.2001] [Citation(s) in RCA: 258] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2000] [Accepted: 03/13/2001] [Indexed: 12/24/2022] Open
Abstract
Upregulated epidermal growth factor (EGF) receptor (EGFR) expression and EGFR-induced signaling have been correlated with progression to invasion and metastasis in a wide variety of carcinomas, but the mechanism behind this is not well understood. We show here that, in various human carcinoma cells that overexpress EGFR, EGF treatment induced rapid tyrosine dephosphorylation of focal adhesion kinase (FAK) associated with downregulation of its kinase activity. The downregulation of FAK activity was both required and sufficient for EGF-induced refractile morphological changes, detachment of cells from the extracellular matrix, and increased tumor cell motility, invasion, and metastasis. Tumor cells with downregulated FAK activity became less adherent to the extracellular matrix. However, once cells started reattaching, FAK activity was restored by activated integrin signaling. Moreover, this process of readhesion and spreading could not be abrogated by further EGF stimulation. Interruption of transforming growth factor alpha-EGFR autocrine regulation with an EGFR tyrosine kinase inhibitor led to a substantial increase in FAK tyrosine phosphorylation and inhibition of tumor cell invasion in vitro. Consistent with this, FAK tyrosine phosphorylation was reduced in cells from tumors growing in transplanted, athymic, nude mice, which have an intact autocrine regulation of the EGFR. We suggest that the dynamic regulation of FAK activity, initiated by EGF-induced downregulation of FAK leading to cell detachment and increased motility and invasion, followed by integrin-dependent reactivation during readhesion, plays a role in EGF-associated tumor invasion and metastasis.
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Affiliation(s)
- Z Lu
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
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9
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Kraker AJ, Hartl BG, Amar AM, Barvian MR, Showalter HD, Moore CW. Biochemical and cellular effects of c-Src kinase-selective pyrido[2, 3-d]pyrimidine tyrosine kinase inhibitors. Biochem Pharmacol 2000; 60:885-98. [PMID: 10974196 DOI: 10.1016/s0006-2952(00)00405-6] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Increased expression or activity of c-Src tyrosine kinase has been associated with the transformed phenotype in tumor cells and with progression of neoplastic disease. A number of pyrido[2, 3-d]pyrimidines have been characterized biochemically and in cells as part of an assessment of their potential as anti-tumor agents. The compounds were ATP-competitive inhibitors of c-Src kinase with IC(50) values < 10 nM and from 6 to >100-fold selectivity for c-Src tyrosine kinase relative to basic fibroblast growth factor receptor (bFGFr) tyrosine kinase, platelet-derived growth factor receptor (PDGFr) tyrosine kinase, and epidermal growth factor receptor (EGFr) tyrosine kinase. The compounds yielded IC(50) values < 5 nM against Lck. Human colon tumor cell growth in culture was inhibited, as was colony formation in soft agar at concentrations < 1 microM. Phosphorylation of the c-Src cellular substrates paxillin, p130(cas), and Stat3 was also inhibited at concentrations < 1 microM. Autophosphorylation of EGFr tyrosine kinase or PDGFr tyrosine kinase was not inhibited by c-Src inhibitors, thus showing the selective nature of the compounds in cells. In a mitogenesis assay measuring thymidine incorporation stimulated by specific mitogens, the c-Src tyrosine kinase inhibitors reduced incorporated thymidine in a manner consistent with previously reported roles of c-Src in mitogenic signaling. Progression through the cell cycle was inhibited at G(2)/M in human colon tumor cells treated with two of the c-Src-selective compounds, which is also consistent with earlier reports describing a requirement for active c-Src tyrosine kinase for G(2) to M phase progression. The compounds described here are selective inhibitors of c-Src tyrosine kinase and have antiproliferative effects in tumor cells consistent with inhibition of c-Src.
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Affiliation(s)
- A J Kraker
- Department of Cancer Research Parke-Davis Pharmaceutical Research, Division of the Warner-Lambert Co., Ann Arbor, MI 48105, USA.
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Demir Weusten AY, Groothuis PG, Dunselman GA, de Goeij AF, Arends JW, Evers JL. Morphological changes in mesothelial cells induced by shed menstrual endometrium in vitro are not primarily due to apoptosis or necrosis. Hum Reprod 2000; 15:1462-8. [PMID: 10875851 DOI: 10.1093/humrep/15.7.1462] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In a previous study on the pathogenesis of endometriosis, we observed that constituents of menstrual effluent induce morphological alterations in human mesothelial cells. In this study, we investigated whether these alterations were associated with apoptosis or necrosis or were the result of cellular remodelling. After overnight incubation of confluent monolayers of human omental mesothelial cells (HOMEC) with conditioned media prepared from menstrual effluent shed anterogradely, severe alterations in morphology were observed. Typical polygonal mesothelial cell cultures at confluency acquired elongated spindle morphology, resulting in gaps between the cells. In contrast, mesothelial cells from the control groups receiving culture medium only, retained a normal morphology. Immunofluorescence staining revealed that cytokeratin, vimentin and actin filaments were still present, homogeneously distributed in the cell cytoplasm following changes in morphology. To evaluate whether the morphological alterations were associated with apoptosis and/or necrosis, the cells were stained with the M30 CytoDeath antibody or annexin V with propidium iodide and analysed using flow cytometry. The results showed that only a small percentage (1-7%) of the affected HOMEC were undergoing apoptosis or necrosis. We conclude that the profoundly altered morphology of HOMEC is a result of cellular remodelling and that the role of apoptosis and necrosis is negligible. Soluble paracrine factors released by cells isolated from menstrual effluent shed anterogradely may induce a reorganization of the cytoskeleton. As a result, the underlying basement membrane will be exposed and the mesothelium may no longer prevent implantation of endometrium shed retrogradely into the peritoneum, thus facilitating the development of endometriosis.
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Affiliation(s)
- A Y Demir Weusten
- Research Institute Growth and Development (GROW), Departments of Obstetrics and Gynaecology, Academisch Ziekenhuis and Maastricht University, Maastricht, The Netherlands.
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Cassinelli G, Lanzi C, Pensa T, Gambetta RA, Nasini G, Cuccuru G, Cassinis M, Pratesi G, Polizzi D, Tortoreto M, Zunino F. Clavilactones, a novel class of tyrosine kinase inhibitors of fungal origin. Biochem Pharmacol 2000; 59:1539-47. [PMID: 10799650 DOI: 10.1016/s0006-2952(00)00278-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Targeting of deregulated protein tyrosine kinases has been proposed as a new approach in the therapeutic intervention against pathological processes including proliferative disorders and cancer. Using a screening approach based on a comparative evaluation of antiproliferative effects in a panel of tumor cells with differential expression of protein tyrosine kinases, three benzoquinoid macrolidic fungal metabolites produced by Clitocybe clavipes, clavilactones A, B, and D (CA, CB, and CD) and two semisynthetic derivatives of these products, diacetyl-CA and dimethyl-CA, were identified as inhibitors of protein tyrosine kinases. Naturally occurring CA, CB, and CD showed inhibitory activity in kinase assays against the Ret/ptc1 and epidermal growth factor receptor (EGF-R) tyrosine kinases, while being less effective against the v-Abl tyrosine kinase and p34(cdc2) serine/threonine kinase (IC(50) 2.8, 5.5, 81.3, and 128 microM respectively, for the most potent compound CD). CB was shown to be a non-competitive inhibitor of EGF-R with respect to ATP or poly(Glu(6)Ala(3)Tyr). CD also preferentially inhibited the growth of A431 cells, which overexpress a constitutively active EGF-R, as opposed to IGROV-1 and SKOV-3 cells, which express low levels of the receptor. Further, EGF-R was shown to be a target for clavilactones in A431 cells, since EGF-induced receptor autophosphorylation was inhibited in the presence of CB, CD, and diacetyl-CA. Both CD and diacetyl-CA displayed weak activity when administered daily (i.p.) to mice bearing ascitic A431 tumor. These findings indicate that clavilactones represent the prototypes of a new structural class of tyrosine kinase inhibitors deserving further investigation.
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Affiliation(s)
- G Cassinelli
- Oncologia Sperimentale B, Istituto Nazionale per lo Studio e la Cura dei Tumori, 20133, Milan, Italy
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Voldborg BR, Damstrup L, Spang-Thomsen M, Poulsen HS. Epidermal growth factor receptor (EGFR) and EGFR mutations, function and possible role in clinical trials. Ann Oncol 1997; 8:1197-206. [PMID: 9496384 DOI: 10.1023/a:1008209720526] [Citation(s) in RCA: 298] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) is a growth factor receptor that induces cell differentiation and proliferation upon activation through the binding of one of its ligands. The receptor is located at the cell surface, where the binding of a ligand activates a tyrosine kinase in the intracellular region of the receptor. This tyrosine kinase phosphorylates a number of intracellular substrates that activates pathways leading to cell growth, DNA synthesis and the expression of oncogenes such as fos and jun. EGFR is thought to be involved the development of cancer, as the EGFR gene is often amplified, and/or mutated in cancer cells. In this review we will focus on: (I) the structure and function of EGFR, (II) implications of receptor/ligand coexpression and EGFR mutations or overexpression, (III) its effect on cancer cells, (IV) the development of the malignant phenotype and (V) the clinical aspects of therapeutic targeting of EGFR.
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Affiliation(s)
- B R Voldborg
- Section for Radiation Biology, Finsen Centre, Rigshospitalet, Copenhagen, Denmark
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