scholarly journals Requirement of the integrin beta 3 subunit for carcinoma cell spreading or migration on vitronectin and fibrinogen

1992 ◽  
Vol 117 (5) ◽  
pp. 1101-1107 ◽  
Author(s):  
DI Leavesley ◽  
GD Ferguson ◽  
EA Wayner ◽  
DA Cheresh
Keyword(s):  
Surface Expression ◽  
Porous Membrane ◽  
Biological Properties ◽  
Carcinoma Cells ◽  
Dependent Manner ◽  
Focal Contacts ◽  
Beta 1 Integrin ◽  
Alpha V Beta 3 ◽  
Integrin Beta 3 ◽  
Extracellular Environment

FG human pancreatic carcinoma cells use integrin alpha v beta 5 as their primary vitronectin receptor since they fail to express integrin alpha v beta 3. These cells are unable to form focal contacts, spread, or migrate on vitronectin but readily do so on collagen in a beta 1 integrin-dependent manner. Transfection of FG cells with a cDNA encoding the integrin beta 3 subunit results in the surface expression of a functional integrin alpha v beta 3 heterodimer providing these cells with novel adhesive and biological properties. Specifically, FG cells expressing beta 3 acquire the capacity to attach and spread on vitronectin as well as fibrinogen with beta 3 localization to focal contacts. Moreover, these cells gain the capacity to migrate through a porous membrane in response to either vitronectin or fibrinogen. These results demonstrate that the beta 3 and beta 5 integrin subunits when associated with alpha v, promote distinct cellular responses to a vitronectin extracellular environment.

scholarly journals Beta 1 integrin-dependent and -independent polymerization of fibronectin.

1996 ◽  
Vol 132 (1) ◽  
pp. 227-238 ◽  
Author(s):  
K Wennerberg ◽  
L Lohikangas ◽  
D Gullberg ◽  
M Pfaff ◽  
S Johansson ◽  
...  
Keyword(s):  
Large Cell ◽  
Mouse Cell ◽  
Integrin Subunit ◽  
Cell Binding ◽  
Matrix Assembly ◽  
Focal Contacts ◽  
Fibronectin Matrix ◽  
Beta 1 Integrin ◽  
Alpha V Beta 3 ◽  
Fibronectin Fibrils

The mouse cell line GD25, which lacks expression of the beta 1 family of integrin heterodimers due to disruption of the beta 1 integrin subunit gene, was used for expression of full-length cDNA coding for splice variant A of the mouse beta 1 integrin subunit. In a stably transformed clone (GD25-beta 1A), the expressed protein was found to form functional heterodimeric receptors together with the subunits alpha 3, alpha 5, and alpha 6. Both GD25 and GD25-beta 1A attached to fibronectin and formed focal contacts which contained alpha v beta 3, but no detectable alpha 5 beta 1A. The presence of GRGDS peptide allowed alpha 5 beta 1A to locate to focal contacts of GD25-beta 1A cultured on fibronectin, while the beta 1-null GD25 cells were unable to attach under these conditions. Affinity chromatography revealed that alpha 5 beta 1A and alpha v beta 3 could bind to a large cell-binding fragment of fibronectin. alpha 5 beta 1A strongly promoted polymerization of fibronectin into a fibrillar network on top of the cells. Whereas little alpha v beta 3 was colocalized with the fibronectin fibrils in GD25-beta 1A cells, this integrin was able to support fibronectin fibril polymerization in GD25 cells. However, the alpha v beta 3-induced polymerization was less efficient and occurred mainly in dense cultures of the GD25 cells. Thus, while both alpha 5 beta 1A and alpha v beta 3 are able to support adhesion to fibronectin, alpha v beta 3 dominates in the formation of focal contacts, and alpha 5 beta 1A has a prime function in fibronectin matrix assembly. This is the first report on fibronectin matrix assembly in the absence of beta 1 integrins.

scholarly journals Integrins in point contacts mediate cell spreading: factors that regulate integrin accumulation in point contacts vs. focal contacts.

1993 ◽  
Vol 120 (1) ◽  
pp. 261-271 ◽  
Author(s):  
N Tawil ◽  
P Wilson ◽  
S Carbonetto
Keyword(s):  
Cell Types ◽  
Laminin Receptor ◽  
Dependent Manner ◽  
Point Contacts ◽  
Focal Contacts ◽  
Beta 1 Integrin ◽  
Mediate Cell ◽  
Different Cell Types

We have studied the function and distribution of the alpha 1 beta 1, alpha 5 beta 1 and alpha 6 beta 1 heterodimers on type-1 astrocytes with antibodies specific for integrin subunits (alpha 1, alpha 5, alpha 6, and beta 1). The alpha 1 beta 1 heterodimer mediates adhesion to laminin and collagen, the alpha 5 beta 1 to fibronectin in an RGD-dependent manner. The alpha 5 beta 1 integrin is found in focal contacts in long-term cultures of well-spread astrocytes colocalizing with vinculin and the termini of actin stress fibers. alpha 1 beta 1 heterodimers can occasionally be found as small aggregates within focal contacts but they do not accumulate there. Instead, alpha 1 beta 1 integrins are found in punctate deposits called point contacts which are distributed over the upper and the lower cell surfaces whether laminin, collagen, fibronectin or polylysine is used as a substratum. Unlike focal contacts, point contacts contain clathrin but rarely codistribute with actin or vinculin. Two observations indicate that these point contacts are functional. First, mAb 3A3, directed against the rat alpha 1 subunit, inhibits the attachment of astrocytes to laminin and collagen. Second, during the spreading of astrocytes, a band of point contacts forms around the cell perimeter at a time when no focal contacts are visible. While alpha 1 beta 1 integrins are found only in point contacts in astrocytes, the alpha 6 beta 1 integrin, another laminin receptor, is localized within focal contacts. Moreover, alpha 1 beta 1 heterodimers accumulate in focal contacts in fibroblasts. Thus, the alpha subunit contributes, independent of its ligand, to functional integrin heterodimer accumulation in focal contacts or in point contacts. This accumulation varies among different cell types with apparently identical heterodimers as well as with the motile state (spreading vs. flattened) of the same cells.

scholarly journals RASSF1A inhibits PDGFB-driven malignant phenotypes of nasopharyngeal carcinoma cells in a YAP1-dependent manner

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Ying-Ying Liang ◽  
Xu-Bin Deng ◽  
Xian-Tao Lin ◽  
Li-Li Jiang ◽  
Xiao-Ting Huang ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Underlying Mechanism ◽  
Carcinoma Cells ◽  
Dependent Manner ◽  
Transcriptional Coactivator ◽  
Actin Remodeling ◽  
Aggressive Tumor ◽  
Subunit B

Abstract Nasopharyngeal carcinoma (NPC) is a highly aggressive tumor characterized by distant metastasis. Deletion or down-regulation of the tumor suppressor protein ras-association domain family protein1 isoform A (RASSF1A) has been confirmed to be a key event in NPC progression; however, little is known about the effects or underlying mechanism of RASSF1A on the malignant phenotype. In the present study, we observed that RASSF1A expression inhibited the malignant phenotypes of NPC cells. Stable silencing of RASSF1A in NPC cell lines induced self-renewal properties and tumorigenicity in vivo/in vitro and the acquisition of an invasive phenotype in vitro. Mechanistically, RASSF1A inactivated Yes-associated Protein 1 (YAP1), a transcriptional coactivator, through actin remodeling, which further contributed to Platelet Derived Growth Factor Subunit B (PDGFB) transcription inhibition. Treatment with ectopic PDGFB partially increased the malignancy of NPC cells with transient knockdown of YAP1. Collectively, these findings suggest that RASSF1A inhibits malignant phenotypes by repressing PDGFB expression in a YAP1-dependent manner. PDGFB may serve as a potential interest of therapeutic regulators in patients with metastatic NPC.

scholarly journals Isolation of a highly specific ligand for the alpha 5 beta 1 integrin from a phage display library

1994 ◽  
Vol 124 (3) ◽  
pp. 373-380 ◽  
Author(s):  
E Koivunen ◽  
B Wang ◽  
E Ruoslahti
Keyword(s):  
Phage Display ◽  
Cyclic Peptide ◽  
Cell Attachment ◽  
Phage Display Library ◽  
Cell Binding ◽  
Rgd Peptides ◽  
Beta 1 Integrin ◽  
Alpha V Beta 3 ◽  
Integrin Ligand ◽  
Specific Ligand

Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR sequence occurs in the cell-binding region of the fibronectin molecule, this sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a sequence RRETAWA that does not bear obvious resemblance to known integrin ligand sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.

scholarly journals Structure and Function of a Vimentin-associated Matrix Adhesion in Endothelial Cells

2001 ◽  
Vol 12 (1) ◽  
pp. 85-100 ◽  
Author(s):  
Meredith Gonzales ◽  
Babette Weksler ◽  
Daisuke Tsuruta ◽  
Robert D. Goldman ◽  
Kristine J. Yoon ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factors ◽  
Endothelial Cell ◽  
Branching Morphogenesis ◽  
Basement Membranes ◽  
Αvβ3 Integrin ◽  
Dependent Manner ◽  
Matrix Adhesion ◽  
Focal Contacts

The α4 laminin subunit is a component of endothelial cell basement membranes. An antibody (2A3) against the α4 laminin G domain stains focal contact-like structures in transformed and primary microvascular endothelial cells (TrHBMECs and HMVECs, respectively), provided the latter cells are activated with growth factors. The 2A3 antibody staining colocalizes with that generated by αv and β3 integrin antibodies and, consistent with this localization, TrHBMECs and HMVECs adhere to the α4 laminin subunit G domain in an αvβ3-integrin–dependent manner. The αvβ3 integrin/2A3 antibody positively stained focal contacts are recognized by vinculin antibodies as well as by antibodies against plectin. Unusually, vimentin intermediate filaments, in addition to microfilament bundles, interact with many of the αvβ3 integrin-positive focal contacts. We have investigated the function of α4-laminin and αvβ3-integrin, which are at the core of these focal contacts, in cultured endothelial cells. Antibodies against these proteins inhibit branching morphogenesis of TrHBMECs and HMVECs in vitro, as well as their ability to repopulate in vitro wounds. Thus, we have characterized an endothelial cell matrix adhesion, which shows complex cytoskeletal interactions and whose assembly is regulated by growth factors. Our data indicate that this adhesion structure may play a role in angiogenesis.

scholarly journals Invasive Potential of Melanoma Cells Correlates with the Expression of MT1-MMP and Regulated by Modulating Its Association with Motility Receptors via N-Glycosylation on the Receptors

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Amit Ranjan ◽  
Rajiv D. Kalraiya
Keyword(s):  
Basement Membrane ◽  
Surface Expression ◽  
Cellular Adhesion ◽  
Matrix Remodeling ◽  
Dependent Manner ◽  
Invasive Potential ◽  
Upar Expression ◽  
Matrix Components ◽  
Multiple Levels ◽  
Matrix Degrading Enzymes

Matrix remodeling and invasion of basement membrane are the major determinants of malignant progression. Matrix degrading enzymes play a pivotal role in this process and have been shown to be regulated at multiple levels. Using high metastatic B16F10 and its invasive variant B16BL6 cells, we previously demonstrated that the expression ofβ1,6 branched N-oligosaccharides promotes cellular adhesion on different matrix components which in turn induces secretion of MMP9. The present investigations report that although the two cell lines do not differ in the expression of uPAR, expression of MT1-MMP is significantly higher on B16BL6 cells. Analysis of the transcripts of tissue inhibitors of matrix metalloproteinases (TIMPs) showed that expression of both TIMP1 and TIMP2 correlates negatively with the invasive potential of cells. CD44 andβ1 integrin, the two important receptors involved in motility, were identified to carryβ1,6 branched N-oligosaccharides in an invasive potential dependent manner. However, their glycosylation status did not appear to influence their surface expression. Although glycosylation on CD44 had no effect, that onβ1 integrin significantly affected association ofβ1 integrin with MT1-MMP. The results thus demonstrate that the cancer cells use multiple mechanisms for degradation of matrix in a controlled manner to couple it with movement for effective invasion.

Interleukin 18 (IL-18) as a target for immune intervention.

2016 ◽  
Vol 63 (1) ◽  
Author(s):  
Sebastian Wawrocki ◽  
Magdalena Druszczynska ◽  
Magdalena Kowalewicz-Kulbat ◽  
Wieslawa Rudnicka
Keyword(s):  
Surface Expression ◽  
Dependent Manner ◽  
Interleukin 18 ◽  
T Helper ◽  
Immune Intervention ◽  
Inhibitory Protein ◽  
Ifn Gamma ◽  
Potent Inducer ◽  
Cell Responses ◽  
Th 1

Interleukin 18 (IL-18) is a pleiotropic cytokine involved in the regulation of innate and acquired immune response. In the milieu of IL-12 or IL-15, IL-18 is a potent inducer of IFN-gamma in natural killer (NK) cells and CD4 T helper (Th) 1 lymphocytes. However, IL-18 also modulates Th2 and Th17 cell responses, as well as the activity of CD8 cytotoxic cells and neutrophils, in a host microenvironment-dependent manner. It is produced by various hematopoietic and nonhematopoietic cells, including dendritic cells and macrophages. In an organism, bioactivity of the cytokine depends on the intensity of IL-18 production, the level of its natural inhibitory protein - IL-18BP (IL-18 binding protein) and the surface expression of IL-18 receptors (IL-18R) on the responding cells. This review summarizes the biology of the IL-18/IL-18BP/IL-18R system and its role in the host defense against infections. The prospects for IL-18 application in immunotherapeutic or prophylactic interventions in infectious and non-infectious diseases are discussed.

scholarly journals Structures linking microfilament bundles to the membrane at focal contacts

1993 ◽  
Vol 122 (2) ◽  
pp. 485-496 ◽  
Author(s):  
SJ Samuelsson ◽  
PW Luther ◽  
DW Pumplin ◽  
RJ Bloch
Keyword(s):  
Single Bundle ◽  
Actin Microfilaments ◽  
Lateral Interactions ◽  
Membrane Interactions ◽  
Membrane Particles ◽  
Focal Contacts ◽  
Microfilament Bundles ◽  
Immunogold Cytochemistry ◽  
Beta 1 Integrin

We used quick-freeze, deep-etch, rotary replication and immunogold cytochemistry to identify a new structure at focal contacts. In Xenopus fibroblasts, elongated aggregates of particles project from the membrane to contact bundles of actin microfilaments. Before terminating, a single bundle of microfilaments interacts with several aggregates that appear intermittently over a distance of several microns. Aggregates are enriched in proteins believed to mediate actin-membrane interactions at focal contacts, including beta 1-integrin, vinculin, and talin, but they appear to contain less alpha-actinin and filamin. We also identified a second, smaller class of aggregates of membrane particles that contained beta 1-integrin but not vinculin or talin and that were not associated with actin microfilaments. Our results indicate that vinculin, talin, and beta 1-integrin are assembled into distinctive structures that mediate multiple lateral interactions between microfilaments and the membrane at focal contacts.

Human MutT Homolog 1 (MTH1) Inhibitor Reduces the Biological Activity of Ovarian Carcinoma Cells

2022 ◽  
Vol 12 (5) ◽  
pp. 907-913
Author(s):  
Liyan Zhong ◽  
Yi Yi ◽  
Qian Liu ◽  
Yan Peng
Keyword(s):  
Biological Activity ◽  
Ovarian Carcinoma ◽  
Biological Activities ◽  
Carcinoma Cells ◽  
Dependent Manner ◽  
Ovarian Carcinoma Cells ◽  
Proliferative Rate ◽  
Skov3 Cells ◽  
Significant Difference ◽  
Dose Dependent

This study intends to discuss the mechanism of MTH1 inhibitor (TH588) in the biological activity of ovarian carcinoma cells. A2780 and SKOV-3 cells were treated with different concentrations of TH588 and assigned into AT group (control), BT group (8 μmol/L TH588), CT group (16 μmol/L), DT group (32 μmol/L), ET group (64 μmol/L) and FT group (128 μmol/L) followed by measuring level of Bcl-2 and Bax by Western blot and PCR, and cell biological activities by MTT, FCM and Transwell chamber assay. The cell proliferative rate was not affected in AT group, but was lower in other groups in a reverse dose-dependent manner. There was significant difference on apoptotic rate and cell invasion among groups with increased apoptosis and reduce invasion after TH588 treatment. FT group showed lowest expression of Bcl-2 and Bax compared to other groups. In conclusion, the biological activity of A2780/SKOV3 cells could be reduced by MTH1 inhibitor which was probably through regulation of Bax and Bcl-2 expression.

Oocyte proteomics: localisation of mouse zona pellucida protein 3 to the plasma membrane of ovulated mouse eggs

2004 ◽  
Vol 16 (2) ◽  
pp. 69 ◽  
Author(s):  
S. A. Coonrod ◽  
M. E. Calvert ◽  
P. P. Reddi ◽  
E. N. Kasper ◽  
L. C. Digilio ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Indirect Immunofluorescence ◽  
Zona Pellucida ◽  
Surface Expression ◽  
Surface Proteins ◽  
2D Electrophoresis ◽  
Dependent Manner ◽  
Two Dimensional ◽  
Phase Partitioning ◽  
Proteomic Approach

In order to gain a deeper understanding of the molecular underpinnings of sperm–egg interaction and early development, we have used two-dimensional (2D) electrophoresis, avidin blotting and tandem mass spectrometry to identify, clone and characterise abundant molecules from the mouse egg proteome. Two-dimensional avidin blots of biotinylated zona-free eggs revealed an abundant approximately 75-kDa surface-labelled heterogeneous protein possessing a staining pattern similar to that of the zona pellucida glycoprotein, mouse ZP3 (mZP3). In light of this observation, we investigated whether mZP3 specifically localises to the plasma membrane of mature eggs. Zona pellucidae of immature mouse oocytes and mature eggs were removed using acid Tyrode’s solution, chymotrypsin or mechanical shearing. Indirect immunofluorescence using the mZP3 monoclonal antibody (mAb) IE-10 demonstrated strong continuous staining over the entire surface of immature oocytes and weak microvillar staining on ovulated eggs, regardless of the method of zona removal. Interestingly, in mature eggs, increased fluorescence intensity was observed following artificial activation and fertilisation, whereas little to no fluorescence was observed in degenerated eggs. The surface localisation of ZP3 on mature eggs was supported by the finding that the IE-10 mAb immunoprecipitated an approximate 75-kDa protein from lysates of biotinylated zona-free eggs. To further investigate the specificity of the localisation of mZP3 to the oolemma, indirect immunofluorescence was performed using the IE-10 mAb on both CV-1 and CHO cells transfected with full-length recombinant mZP3 (re-mZP3). Plasma membrane targeting of the expressed re-mZP3 protein was observed in both cell lines. The membrane association of re-mZP3 was confirmed by the finding that biotinylated re-mZP3 (approximately 75 kDa) is immunoprecipitated from the hydrophobic phase of Triton X-114 extracts of transfected cells following phase partitioning. Immunoprecipitation assays also demonstrated that surface re-mZP3 was released from transfected CV-1 in a time-dependent manner. These results demonstrate that ZP3 is specifically associated with the surface of mature eggs and its subsequent release from the cell surface may represent one mechanism by which ZP3 is secreted. Furthermore, the increase in ZP3 surface expression following fertilisation suggests that ZP3 may have a functional role during sperm–oolemma binding and fusion. These results also validate the usefulness of using the 2D proteomic approach to identify and characterise egg-surface proteins.

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