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Marques MPM, Gianolio D, Ramos S, Batista de Carvalho LAE, Aureliano M. An EXAFS Approach to the Study of Polyoxometalate-Protein Interactions: The Case of Decavanadate-Actin. Inorg Chem 2017; 56:10893-10903. [PMID: 28858484 DOI: 10.1021/acs.inorgchem.7b01018] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
EXAFS and XANES experiments were used to assess decavanadate interplay with actin, in both the globular and polymerized forms, under different conditions of pH, temperature, ionic strength, and presence of ATP. This approach allowed us to simultaneously probe, for the first time, all vanadium species present in the system. It was established that decavanadate interacts with G-actin, triggering a protein conformational reorientation that induces oxidation of the cysteine core residues and oxidovanadium (VIV) formation. The local environment of vanadium's absorbing center in the [decavanadate-protein] adducts was determined, a V-SCys coordination having been verified experimentally. The variations induced in decavanadate's EXAFS profile by the presence of actin were found to be almost totally reversed by the addition of ATP, which constitutes a solid proof of decavanadate interaction with the protein at its ATP binding site. Additionally, a weak decavanadate interplay with F-actin was suggested to take place, through a mechanism different from that inferred for globular actin. These findings have important consequences for the understanding, at a molecular level, of the significant biological activities of decavanadate and similar polyoxometalates, aiming at potential pharmacological applications.
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Affiliation(s)
- M Paula M Marques
- "Química-Física Molecular" R&D Unit, Department of Chemistry, University of Coimbra , 3004-535 Coimbra, Portugal
- Department of Life Sciences, University of Coimbra , 3000-456 Coimbra, Portugal
| | - Diego Gianolio
- Diamond Light Source, Harwell Science & Innovation Campus , Didcot OX11 0DE, United Kingdom
| | - Susana Ramos
- UCIBIO, REQUIMTE, Departamento de Química, Universidade Nova de Lisboa , 2829-516 Caparica, Portugal
| | - Luís A E Batista de Carvalho
- "Química-Física Molecular" R&D Unit, Department of Chemistry, University of Coimbra , 3004-535 Coimbra, Portugal
| | - Manuel Aureliano
- "Química-Física Molecular" R&D Unit, Department of Chemistry, University of Coimbra , 3004-535 Coimbra, Portugal
- FCT and CCmar, University of Algarve , 8005-139 Faro, Portugal
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2
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Stan MS, Sima C, Cinteza LO, Dinischiotu A. Silicon-based quantum dots induce inflammation in human lung cells and disrupt extracellular matrix homeostasis. FEBS J 2015; 282:2914-29. [PMID: 26032556 DOI: 10.1111/febs.13330] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/11/2015] [Accepted: 05/27/2015] [Indexed: 12/12/2022]
Abstract
Quantum dots (QDs) are nanocrystalline semiconductor materials that have been tested for biological applications such as cancer therapy, cellular imaging and drug delivery, despite the serious lack of information of their effects on mammalian cells. The present study aimed to evaluate the potential of Si/SiO2 QDs to induce an inflammatory response in MRC-5 human lung fibroblasts. Cells were exposed to different concentrations of Si/SiO2 QDs (25-200 μg·mL(-1)) for 24, 48, 72 and 96 h. The results obtained showed that uptake of QDs was dependent on biocorona formation and the stability of nanoparticles in various biological media (minimum essential medium without or with 10% fetal bovine serum). The cell membrane damage indicated by the increase in lactate dehydrogenase release after exposure to QDs was dose- and time-dependent. The level of lysosomes increased proportionally with the concentration of QDs, whereas an accumulation of autophagosomes was also observed. Cellular morphology was affected, as shown by the disruption of actin filaments. The enhanced release of nitric oxide and the increase in interleukin-6 and interleukin-8 protein expression suggested that nanoparticles triggered an inflammatory response in MRC-5 cells. QDs decreased the protein expression and enzymatic activity of matrix metalloproteinase (MMP)-2 and MMP-9 and also MMP-1 caseinase activity, whereas the protein levels of MMP-1 and tissue inhibitor of metalloproteinase-1 increased. The present study reveals for the first time that silicon-based QDs are able to generate inflammation in lung cells and cause an imbalance in extracellular matrix turnover through a differential regulation of MMPs and tissue inhibitor of metalloproteinase-1 protein expression.
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Affiliation(s)
- Miruna-Silvia Stan
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Romania
| | - Cornelia Sima
- National Institute for Laser, Plasma and Radiation Physics, Bucharest-Magurele, Romania
| | | | - Anca Dinischiotu
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Romania
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3
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Qiu X, He X, Huang Q, Liu X, Sun G, Guo J, Yuan D, Yang L, Ban N, Fan S, Tao T, Wang D. Overexpression of CCT8 and its significance for tumor cell proliferation, migration and invasion in glioma. Pathol Res Pract 2015; 211:717-25. [PMID: 26304164 DOI: 10.1016/j.prp.2015.04.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 03/22/2015] [Accepted: 04/01/2015] [Indexed: 01/01/2023]
Abstract
Overexpression of chaperonin containing t-complex polypeptide 1 (TCP1), or CCT, has been reported in various classes of malignancies. However, little is known about the expression of t-complex protein subunits TCP1theta (CCT8) in gliomas. In this study, the expression of CCT8 protein was detected using blotting analysis and immunohistochemistry. CCT8 was found to be overexpressed in gliomas and to correlate with the WHO grade of gliomas. To further investigate the biological function of CCT8 in gliomas, CCT8-silenced U87 glioblastoma multiforme (GBM) and U251MG cells were constructed using a small interference RNA (siRNA) sequence. The knockdown effect of CCT8 on proliferation and invasion in these cells was analyzed using the CCK8, flow cytometry cycle, scratch, transwell invasion and fluorescence assays. Compared with the controls, the glioma cells expressing CCT8-siRNA exhibited a significantly decreased proliferation and invasion capacity, as well as a dysregulated cell cytoskeleton. This study showed that high CCT8 protein expression might be related to poor outcome of glioma, and that CCT8 regulates the proliferation and invasion of glioblastomas.
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Affiliation(s)
- Xiaojun Qiu
- Department of Neurosurgery, Affiliated Hospital, Nantong University, Nantong 226001, PR China
| | - Xiaojuan He
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Department of Pathology, Medical College, Nantong University, Nantong 226001, PR China
| | - Qingfeng Huang
- Department of Neurosurgery, Affiliated Hospital, Nantong University, Nantong 226001, PR China
| | - Xianchen Liu
- Department of Neurosurgery, Affiliated Hospital, Nantong University, Nantong 226001, PR China
| | - Guan Sun
- Department of Neurosurgery, Affiliated Hospital, Nantong University, Nantong 226001, PR China
| | - Jun Guo
- Department of Neurosurgery, Affiliated Hospital, Nantong University, Nantong 226001, PR China
| | - Damin Yuan
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Department of Pathology, Medical College, Nantong University, Nantong 226001, PR China
| | - Lixiang Yang
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Department of Pathology, Medical College, Nantong University, Nantong 226001, PR China
| | - Na Ban
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Department of Pathology, Medical College, Nantong University, Nantong 226001, PR China
| | - Shaochen Fan
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Department of Pathology, Medical College, Nantong University, Nantong 226001, PR China
| | - Tao Tao
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Department of Pathology, Medical College, Nantong University, Nantong 226001, PR China.
| | - Donglin Wang
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Department of Pathology, Medical College, Nantong University, Nantong 226001, PR China.
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Differential expression of MMP-2 and MMP-9 activity in megakaryocytes and platelets. Blood 2012; 118:6470-1; author reply 6471-3. [PMID: 22161853 DOI: 10.1182/blood-2011-07-366195] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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5
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Ramos S, Moura JJG, Aureliano M. Actin as a potential target for decavanadate. J Inorg Biochem 2010; 104:1234-9. [PMID: 20807665 DOI: 10.1016/j.jinorgbio.2010.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 08/04/2010] [Accepted: 08/05/2010] [Indexed: 02/07/2023]
Abstract
ATP prevents G-actin cysteine oxidation and vanadyl formation specifically induced by decavanadate, suggesting that the oxometalate-protein interaction is affected by the nucleotide. The ATP exchange rate is increased by 2-fold due to the presence of decavanadate when compared with control actin (3.1×10(-3) s(-1)), and an apparent dissociation constant (k(dapp)) of 227.4±25.7 μM and 112.3±8.7 μM was obtained in absence or presence of 20 μM V(10), respectively. Moreover, concentrations as low as 50 μM of decameric vanadate species (V(10)) increases the relative G-actin intrinsic fluorescence intensity by approximately 80% whereas for a 10-fold concentration of monomeric vanadate (V(1)) no effects were observed. Upon decavanadate titration, it was observed a linear increase in G-actin hydrophobic surface (2.6-fold), while no changes were detected for V(1) (0-200 μM). Taken together, three major ideas arise: i) ATP prevents decavanadate-induced G-actin cysteine oxidation and vanadate reduction; ii) decavanadate promotes actin conformational changes resulting on its inactivation, iii) decavanadate has an effect on actin ATP binding site. Once it is demonstrated that actin is a new potential target for decavanadate, being the ATP binding site a suitable site for decavanadate binding, it is proposed that some of the biological effects of vanadate can be, at least in part, explained by decavanadate interactions with actin.
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Affiliation(s)
- Susana Ramos
- DCBB-FCT and CCMar, University of Algarve, 8005-139 Faro, Portugal
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Santra M, Santra S, Roberts C, Zhang RL, Chopp M. Doublecortin induces mitotic microtubule catastrophe and inhibits glioma cell invasion. J Neurochem 2009; 108:231-45. [PMID: 19094064 DOI: 10.1111/j.1471-4159.2008.05758.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Doublecortin (DCX) is a microtubule (MT) binding protein that induces growth arrest at the G2-M phase of cell cycle in glioma and suppresses tumor xenograft in immunocompromised hosts. DCX expression was found in neuronal cells, but lacking in glioma cells. We tested the hypothesis that DCX inhibits glioma U87 cell mitosis and invasion. Our data showed that DCX synthesizing U87 cells underwent mitotic MT spindle catastrophe in a neurabin II dependent pathway. Synthesis of both DCX and neurabin II were required to induce apoptosis in U87 and human embryonic kidney 293T cells. In DCX expressing U87 cells, association of phosphorylated DCX with protein phosphatase-1 (PP1) in the cytosol disrupted the interaction between kinesin-13 and PP1 in the nucleus and yielded spontaneously active kinesin-13. The activated kinesin-13 caused mitotic MT catastrophe in spindle checkpoint. Phosphorylated-DCX induced depolymerization of actin filaments in U87 cells, down-regulated matrix metalloproteinases-2 and -9, and inhibited glioma U87 cell invasion in a neurabin II dependent pathway. Thus, localization of the DCX-neurabin II-PP1 complex in the cytosol of U87 tumor cells inhibited PP1 phosphatase activities leading to anti-glioma effects via (1) mitotic MT spindle catastrophe that blocks mitosis and (2) depolymerization of actin that inhibits glioma cell invasion.
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Affiliation(s)
- Manoranjan Santra
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
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Hutterer M, Knyazev P, Abate A, Reschke M, Maier H, Stefanova N, Knyazeva T, Barbieri V, Reindl M, Muigg A, Kostron H, Stockhammer G, Ullrich A. Axl and growth arrest-specific gene 6 are frequently overexpressed in human gliomas and predict poor prognosis in patients with glioblastoma multiforme. Clin Cancer Res 2008; 14:130-8. [PMID: 18172262 DOI: 10.1158/1078-0432.ccr-07-0862] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The receptor tyrosine kinase Axl has recently been identified as a critical element in the invasive properties of glioma cell lines. However, the effect of Axl and its ligand growth arrest--specific gene 6 (Gas6) in human gliomas is still unknown. EXPERIMENTAL DESIGN Axl and Gas6 expression was studied in 42 fresh-frozen and 79 paraffin-embedded glioma specimens by means of reverse transcription-PCR and immunohistochemistry. The prognostic value of Axl and Gas6 expression was evaluated using a population-based tissue microarray derived from a cohort of 55 glioblastoma multiforme (GBM) patients. RESULTS Axl and Gas6 were detectable in gliomas of malignancy grades WHO 2 to 4. Moderate to high Axl mRNA expression was found in 61%, Axl protein in 55%, Gas6 mRNA in 81%, and Gas6 protein in 74% of GBM samples, respectively. GBM patients with high Axl expression and Axl/Gas6 coexpression showed a significantly shorter time to tumor progression and an association with poorer overall survival. Comparative immunohistochemical studies showed that Axl staining was most pronounced in glioma cells of pseudopalisades and reactive astrocytes. Additionally, Axl/Gas6 coexpression was observed in glioma cells and tumor vessels. In contrast, Axl staining was not detectable in nonneoplastic brain tissue and Gas6 was strongly expressed in neurons. CONCLUSIONS In human gliomas, Axl and Gas6 are frequently overexpressed in both glioma and vascular cells and predict poor prognosis in GBM patients. Our results indicate that specific targeting of the Axl/Gas6 signaling pathway may represent a potential new approach for glioma treatment.
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Affiliation(s)
- Markus Hutterer
- Clinical Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
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Abstract
Angiogenesis, the process by which new branches sprout from existing vessels, requires the degradation of the vascular basement membrane and remodeling of the ECM in order to allow endothelial cells to migrate and invade into the surrounding tissues. Serine, metallo, and cysteine proteinases are 3 types of a family of enzymes that proteolytically degrade various components of extracellular matrix. These proteases release various growth factors and also increase adhesive molecules and signaling pathway molecules upon their activation, which plays a significant role in angiogenesis. Downregulation of these molecules by antisense/siRNA or synthetic inhibitors decreases the levels of these molecules, inhibits the release of growth factors, and decreases the levels of various signaling pathway molecules, thereby leading to the inhibition of angiogenesis. Furthermore, MMPs degrade specific substrates and release angiogenic inhibitors which inhibit angiogenesis. Downregulation of 2 molecules, such as uPA and uPAR, uPAR and MMP-9, or Cathepsin B and MMP-9, are more effective to inhibit angiogenesis rather than downregulation of single molecules. However, careful testing of these combinations are most important because multiple effects of these combinations play a significant role in angiogenesis.
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Affiliation(s)
- Sajani S Lakka
- Division of Cancer Biology, Department of Biomedical and Therapeutic Sciences, University of Illinois College of Medicine-Peoria, Peoria, IL 61605, USA
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St-Pierre Y, Couillard J, Van Themsche C. Regulation of MMP-9 gene expression for the development of novel molecular targets against cancer and inflammatory diseases. Expert Opin Ther Targets 2005; 8:473-89. [PMID: 15469396 DOI: 10.1517/14728222.8.5.473] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The need to pharmacologically control the proteolytic activity of matrix metalloproteinases (MMPs) has been commonly acknowledged, despite its limited efficacy in clinical trials. Among the reasons that explain this failure is our limited understanding of the signals that control the expression of MMPs in different cell types during different pathological conditions. Thus, future therapies must rely on more selective approaches. With the continually increasing body of proof implicating MMPs in a large number of diseases, it has become a priority to establish the pertinence of molecules involved in the signalling pathways leading to the expression of these enzymes. MMP-9 is a case in point: its dramatic overexpression in cancer and various inflammatory conditions clearly points to the molecular mechanisms controlling its expression as a potential target for eventual rational therapeutic intervention. In this article, recent progress in the signalling pathways that regulate MMP-9 expression is reviewed, and the latest strategies to be considered in the search for a specific inhibitor of its expression are presented.
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Affiliation(s)
- Yves St-Pierre
- INRS-Institut Armand-Frappier, University of Quebec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada.
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10
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Rico-Bautista E, Negrín-Martínez C, Novoa-Mogollón J, Fernández-Perez L, Flores-Morales A. Downregulation of the growth hormone-induced Janus kinase 2/signal transducer and activator of transcription 5 signaling pathway requires an intact actin cytoskeleton. Exp Cell Res 2004; 294:269-80. [PMID: 14980520 DOI: 10.1016/j.yexcr.2003.11.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2003] [Revised: 11/12/2003] [Indexed: 10/26/2022]
Abstract
Transient activation of the signal transducers and activators of transcription (STAT) proteins in response to growth hormone (GH) and other type II cytokines plays a pivotal role on specific gene transcription. The negative regulation of STATs seems to be exerted at the GH receptor (GHR)/Janus Kinase (JAK) complex and involves two main mechanisms: (1) the GH-induced ubiquitination/internalization of GHR and (2) the action of SOCS proteins. Since GH regulates cellular cytoskeleton with potential implications in GH signaling, we investigated the effects of actin cytoskeleton disruption on the kinetics of GH-activated GHR/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 5 (STAT5) signaling pathway. Disruption of the actin-based cytoskeleton with cytochalasin D (CytoD) did not affect the rapid GH induction of JAK2 and STAT5 activities. However, pretreatment of BRL-4 cells with CytoD prolonged both, JAK2/STAT5 tyrosine phosphorylation and STAT5 DNA binding activity, for at least 2 h. Our results demonstrated that the synthesis of the several SOCS proteins (SOCS-1, -2, and -3) was not affected by treatment of the cells with CytoD. On the other hand, the inhibitory actions of SOCS1, 2, and -3 on GH-induced STAT5 reporter activity were partially blocked by disruption of the cytoskeleton. Disassembly of the actin filaments by CytoD is accompanied by accumulation of ubiquitinated forms of GHR but it does not affect GHR internalization. We conclude that the integrity of the actin cytoskeleton network plays an essential role in the negative regulation of GHR/JAK2/STAT5 signaling pathway by facilitating the GHR ubiquitination/degradation through mechanisms acting downstream SOCS.
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Abstract
The invasive nature of brain-tumour cells makes an important contribution to the ineffectiveness of current treatment modalities, as the remaining tumour cells inevitably infiltrate the surrounding normal brain tissue, which leads to tumour recurrence. Such local invasion remains an important cause of mortality and underscores the need to understand in more detail the mechanisms of tumour invasiveness. Several proteases influence the malignant characteristics of gliomas--could their inhibition prove to be a useful therapeutic strategy?
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Affiliation(s)
- Jasti S Rao
- Program of Cancer Biology, Department of Neurosurgery, University of Illinois College of Medicine-Peoria, 1 Illini Drive, Peoria, Illinois 61656, USA.
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12
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Kapoor GS, O'Rourke DM. Mitogenic signaling cascades in glial tumors. Neurosurgery 2003; 52:1425-34; discussion 1434-5. [PMID: 12762887 DOI: 10.1227/01.neu.0000065135.28143.39] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2002] [Accepted: 01/29/2003] [Indexed: 01/29/2023] Open
Abstract
Gliomas are primary central nervous system tumors that arise from astrocytes, oligodendrocytes, or their precursors. Gliomas can be classified into several groups according to histological features. A number of genetic alterations have been identified in human gliomas; these generally affect either signal transduction pathways activated by receptor tyrosine kinases or cell cycle growth arrest pathways. These observed genetic alterations are now being used to complement histopathological diagnosis. The aim of the present review is to give a broad overview of the receptor tyrosine kinase signaling machinery involved in gliomagenesis, with an emphasis on the cooperative interaction between receptor tyrosine kinase signaling and the cell cycle-regulatory machinery. Understanding molecular features of primary glial tumors will eventually allow for target-selective intervention in distinct glioma subsets and a more rational approach to adjuvant therapies for these refractory diseases.
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Affiliation(s)
- Gurpreet S Kapoor
- Department of Neurosurgery, University of Pennsylvania School of Medicine, 36th and Hamilton Walk, Philadelphia, PA 19104, USA
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Shah BH, Alberto Olivares-Reyes J, Yesilkaya A, Catt KJ. Independence of angiotensin II-induced MAP kinase activation from angiotensin type 1 receptor internalization in clone 9 hepatocytes. Mol Endocrinol 2002; 16:610-20. [PMID: 11875120 DOI: 10.1210/mend.16.3.0781] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The agonist-induced internalization of several G protein-coupled receptors is an obligatory requirement for their activation of MAPKs. Studies on the relationship between endocytosis of the angiotensin II (Ang II) type 1 receptor (AT1-R) and Ang II-induced ERK1/2 activation were performed in clone 9 (C9) rat hepatic cells treated with inhibitors of endocytosis [sucrose, phenylarsine oxide (PAO), and concanavalin A]. Although Ang II-induced endocytosis of the AT1-R was prevented by sucrose and PAO, and was partially inhibited by concanavalin A, there was no impairment of Ang II-induced ERK activation. However, the specific epidermal growth factor receptor (EGF-R) kinase inhibitor, AG1478, abolished Ang II-induced activation of ERK1/2. Sucrose and PAO also inhibited EGFinduced internalization of the EGF-R in C9 cells, and the inability of these agents to impair EGF-induced ERK activation suggested that the latter is also independent of receptor endocytosis. In COS-7 cells transiently expressing the rat AT1A-R, Ang II also caused ERK activation through EGF-R transactivation. Furthermore, a mutant AT1A-R with truncated carboxyl terminus and impaired internalization retained full ability to activate ERK1/2 in response to Ang II stimulation. These findings demonstrate that Ang II-induced ERK1/2 activation in C9 hepatocytes is independent of both AT1-R and EGF-R endocytosis and is mediated by transactivation of the EGF-R.
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Affiliation(s)
- Bukhtiar H Shah
- Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4510, USA
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14
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Smolian H, Aurer A, Sittinger M, Zacher J, Bernimoulin JP, Burmester GR, Kolkenbrock H. Secretion of gelatinases and activation of gelatinase A (MMP-2) by human rheumatoid synovial fibroblasts. Biol Chem 2001; 382:1491-9. [PMID: 11727833 DOI: 10.1515/bc.2001.183] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In monolayer cultures human rheumatoid synovial fibroblasts (HRSF) secrete gelatinase A (MMP-2) and, unlike other human fibroblasts, to a minor extent also gelatinase B (MMP-9) as inactive proenzymes. In this regard HRSF resemble the fibrosarcoma cell line HT-1080. Unlike HT-1080, however, HRSF do not increase the secretion of MMP-9 in response to phorbol-12-myristate-13-acetate. This indicates that in HRSF the protein kinase C pathway for an enhanced MMP-9 secretion is inactive. None of the substances used in our study increased MMP-9 secretion, but some of them inhibited MMP-9 secretion. The secretion of MMP-2 could not be enhanced either, not even by dbcAMP, which has been reported to be effective in Sertoli and peritubular cells. Activation of MMP-2 in HRSF could be induced by treatment with concanavalin A (ConA) or cytochalasin D, as was shown for other cell types. This activation was not accompanied by a significant change in the amount of secreted TIMP-1 and TIMP-2. In contrast to reports on human skin fibroblasts, however, the activation of MMP-2 could not be induced in HRSF by treatment of the cells with monensin or sodium orthovanadate. Moreover, monensin was shown to act as an inhibitor of ConA- or cytochalasin D-mediated activation. Additionally, and in contrast to a report on a rat fibroblast cell line, MMP-2 activation is not mediated via the MAP kinase pathway in HRSF: PD 98059, a specific inhibitor of MAP kinase kinase, did not inhibit the activation of MMP-2. Similarly ineffective were PD 169316, an inhibitor for p38 MAP kinase, other inhibitors for protein kinases as lavendustin A, Gö 6983, wortmannin, rapamycin, as well as the protein tyrosine kinase inhibitors herbimycin A and genistein. Only staurosporin, a broad spectrum inhibitor of protein kinases, and the ionophores monensin and A 23187 effectively inhibited MMP-2 activation in HRSF. Our results demonstrate that MMP-2 can be activated by quite different pathways, and that different cells, even when belonging to the fibroblast family, do not necessarily use the same activating pathways.
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Affiliation(s)
- H Smolian
- Department of Rheumatology, University Hospital Charité Berlin, Germany
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15
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Chernock RD, Cherla RP, Ganju RK. SHP2 and cbl participate in alpha-chemokine receptor CXCR4-mediated signaling pathways. Blood 2001; 97:608-15. [PMID: 11157475 DOI: 10.1182/blood.v97.3.608] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Stromal cell-derived factor (SDF)-1alpha and its receptor, CXCR4, play an important role in cell migration, embryonic development, and human immunodeficiency virus infection. However, the cellular signaling pathways that mediate these processes are not fully elucidated. We and others have shown that the binding of SDF-1alpha to CXCR4 activates phosphatidylinositol-3 kinase (PI-3 kinase), p44/42 mitogen-associated protein kinase, and the transcription factor nuclear factor-kappaB, and it also enhances the tyrosine phosphorylation and association of proteins involved in the formation of focal adhesions. In this study, we examined the role of phosphatases in CXCR4-mediated signaling pathways. We observed significant inhibition of SDF-1alpha-induced migration by phosphatase inhibitors in CXCR4-transfected pre-B lymphoma L1.2 cells, Jurkat T cells, and peripheral blood lymphocytes. Further studies revealed that SDF-1alpha stimulation induced robust tyrosine phosphorylation in the SH2-containing phosphatase SHP2. SHP2 associated with the CXCR4 receptor and the signaling molecules SHIP, cbl, and fyn. Overexpression of wild-type SHP2 increased SDF-1alpha-induced chemotaxis. Enhanced activation of fyn and lyn kinases and the tyrosine phosphorylation of cbl were also observed. In addition, SDF-1alpha stimulation enhanced the association of cbl with PI-3 kinase, Crk-L, and 14-3-3beta proteins. Our results suggest that CXCR4-mediated signaling is regulated by SHP2 and cbl, which collectively participate in the formation of a multimeric signaling complex.
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MESH Headings
- 14-3-3 Proteins
- Adaptor Proteins, Signal Transducing
- Cells, Cultured
- Chemokine CXCL12
- Chemokines, CXC/pharmacology
- Chemotaxis, Leukocyte/drug effects
- Enzyme Inhibitors/pharmacology
- Humans
- Intracellular Signaling Peptides and Proteins
- Jurkat Cells
- Lymphocyte Activation
- Lymphocytes/drug effects
- Lymphocytes/metabolism
- Macromolecular Substances
- Nuclear Proteins/metabolism
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases
- Phosphoprotein Phosphatases/antagonists & inhibitors
- Phosphoproteins/metabolism
- Phosphoric Monoester Hydrolases/metabolism
- Phosphotyrosine/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatase, Non-Receptor Type 6
- Protein Tyrosine Phosphatases/genetics
- Protein Tyrosine Phosphatases/metabolism
- Protein Tyrosine Phosphatases/physiology
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins/physiology
- Proto-Oncogene Proteins c-cbl
- Proto-Oncogene Proteins c-fyn
- Receptors, CXCR4/genetics
- Receptors, CXCR4/metabolism
- Signal Transduction
- Transfection
- Tyrosine 3-Monooxygenase/metabolism
- Ubiquitin-Protein Ligases
- src-Family Kinases/metabolism
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Affiliation(s)
- R D Chernock
- Divisions of Experimental Medicine and Hematology/Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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