scholarly journals EGF-R signaling through Fyn kinase disrupts the function of integrin α6β4 at hemidesmosomes

2001 ◽  
Vol 155 (3) ◽  
pp. 447-458 ◽  
Author(s):  
Agnese Mariotti ◽  
Paul A. Kedeshian ◽  
Michael Dans ◽  
Anna Maria Curatola ◽  
Laurent Gagnoux-Palacios ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Kinase Inhibitors ◽  
Egf Receptor ◽  
Lung Metastases ◽  
Squamous Carcinoma ◽  
Cytoplasmic Domain ◽  
Dominant Negative ◽  
Squamous Carcinoma Cells ◽  
Integrin Α6β4

We have examined the mechanism and functional significance of hemidesmosome disassembly during normal epithelial cell migration and squamous carcinoma invasion. Our findings indicate that a fraction of EGF receptor (EGF-R) combines with the hemidesmosomal integrin α6β4 in both normal and neoplastic keratinocytes. Activation of the EGF-R causes tyrosine phosphorylation of the β4 cytoplasmic domain and disruption of hemidesmosomes. The Src family kinase inhibitors PP1 and PP2 prevent tyrosine phosphorylation of β4 and disassembly of hemidesmosomes without interfering with the activation of EGF-R. Coimmunoprecipitation experiments indicate that Fyn and, to a lesser extent, Yes combine with α6β4. By contrast, Src and Lck do not associate with α6β4 to a significant extent. A dominant negative form of Fyn, but not Src, prevents tyrosine phosphorylation of β4 and disassembly of hemidesmosomes. These observations suggest that the EGF-R causes disassembly of hemidesmosomes by activating Fyn, which in turn phosphorylates the β4 cytoplasmic domain. Neoplastic cells expressing dominant negative Fyn display increased hemidesmosomes and migrate poorly in vitro in response to EGF. Furthermore, dominant negative Fyn decreases the ability of squamous carcinoma cells to invade through Matrigel in vitro and to form lung metastases following intravenous injection in nude mice. These results suggest that disruption of hemidesmosomes mediated by Fyn is a prerequisite for normal keratinocyte migration and squamous carcinoma invasion.

Abstract 1703: Involvement of Adam17 in Neointima Formation after Vascular Injury; Potential Role of Tyrosine Phosphorylation on its Activity

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Akinari Hinoki ◽  
Sadaharu Higuchi ◽  
Keita kimura ◽  
Kunie Eguchi ◽  
Michael V Autieri ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Vascular Remodeling ◽  
Egf Receptor ◽  
Dominant Negative ◽  
Neointima Formation ◽  
Balloon Injury ◽  
Signaling Mechanism ◽  
Receptor Transactivation

Angiotensin II (AngII) and its G protein-coupled receptor, AngII type-1 receptor (AT 1 ), play critical roles in mediating cardiovascular diseases such as hypertension and atherosclerosis. It is widely believed that AngII promotes these diseases by inducing vascular remodeling that involves hypertrophy and hyperplasia of vascular smooth muscle cells (VSMCs). We and others have shown that the EGF receptor transactivation pathway is the key signaling mechanism by which AngII induces VSMC growth. Recently, we have further reported that production of HB-EGF via a metalloprotease, ADAM17, leads to EGF receptor transactivation by AngII in vitro. Here, we hypothesised that tyrosine phosphorylation of ADAM17 is essential for ADAM17 activation by the AT 1 receptor in VSMCs, and that ADAM17 is a critical target of intervention for prevention of vascular remodeling in vivo. Our result revealed that not only a forced expression of dominant-negative (dn) ADAM17-E406A by adenovirus but also the tyrosine phosphorylation incapable ADAM17-Y702F mutant markedly inhibited AngII-induced EGF receptor transactivation compared to the stimulated control in vector-infected VSMCs. The neointimal cells appeared 14 days after balloon injury are strongly positive for ADAM17 immunostaining. Moreover, we observed marked inhibition of intimal hyperplasia in dnADAM17 adenovirus treated carotid artery after the balloon injury. We also confirmed marked expression of dnADAM17 in the artery after the virus infection. Taken together, these results suggest the involvement of ADAM17 in neointima formation. ADAM17 may be activated at the lesion by an upstream tyrosine kinase in response to AngII and other hormonal factors. This research has received full or partial funding support from the American Heart Association, AHA National Center.

scholarly journals Involvement of Src Family Kinases in N-Cadherin Phosphorylation and β-Catenin Dissociation during Transendothelial Migration of Melanoma Cells

2006 ◽  
Vol 17 (3) ◽  
pp. 1261-1272 ◽  
Author(s):  
Jianfei Qi ◽  
Junfu Wang ◽  
Olena Romanyuk ◽  
Chi-Hung Siu
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Phosphorylation ◽  
Nuclear Translocation ◽  
Temporal Correlation ◽  
Transendothelial Migration ◽  
Cytoplasmic Domain ◽  
Melanoma Cells ◽  
Src Family Kinases ◽  
Dominant Negative

N-cadherin is recruited to the heterotypic contact during transendothelial migration of melanoma cells in a coculture system with tumor cells seeded on top of a monolayer of endothelial cells. However, β-catenin dissociates from N-cadherin and redistributes to the nucleus of transmigrating melanoma cells to activate gene transcription. In this report, we demonstrate that Src becomes activated at the heterotypic contact between the transmigrating melanoma cell and neighboring endothelial cells. Src activation shows close temporal correlation with tyrosine phosphorylation of N-cadherin. Expression of a dominant-negative Src in melanoma cells blocks N-cadherin phosphorylation, β-catenin dissociation, and nuclear translocation in transmigrating cells, consistent with the involvement of Src family kinases. In in vitro binding assays, Src-mediated phosphorylation of the N-cadherin cytoplasmic domain results in a significant reduction in β-catenin binding. Although five phospho-tyrosine residues can be identified on the N-cadherin cytoplasmic domain by mass spectrometry, site-specific mutagenesis indicates that Tyr-860 is the critical amino acid involved in β-catenin binding. Overexpression of N-cadherin carrying the Y860F mutation inhibits the transmigration of transfected cells across the endothelium. Together, the data suggest a novel role for tyrosine phosphorylation of N-cadherin by Src family kinases in the regulation of β-catenin association during transendothelial migration of melanoma cells.

Utilizing ICG Spectroscopical Properties for Real-Time Nanoparticle Release Quantification In vitro and In vivo in Imaging Setups

2020 ◽  
Vol 26 (31) ◽  
pp. 3828-3833 ◽  
Author(s):  
Tuula Peñate-Medina ◽  
Eike Kraas ◽  
Kunliang Luo ◽  
Jana Humbert ◽  
Hanwen Zhu ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Pure Water ◽  
Squamous Carcinoma ◽  
Peak Shift ◽  
Intensity Increase ◽  
Nude Mouse Model ◽  
Absorption And Emission ◽  
Squamous Carcinoma Cells

Background: Nanoparticle imaging and tracking the release of the loaded material from the nanoparticle system have attracted significant attention in recent years. If the release of the loaded molecules could be monitored reliably in vivo, it would speed up the development of drug delivery systems remarkably. Methods: Here, we test a system that uses indocyanine green (ICG) as a fluorescent agent for studying release kinetics in vitro and in vivo from the lipid iron nanoparticle delivery system. The ICG spectral properties like its concentration dependence, sensitivity and the fluctuation of the absorption and emission wavelengths can be utilized for gathering information about the change of the ICG surrounding. Results: We have found that the absorption, fluorescence, and photoacoustic spectra of ICG in lipid iron nanoparticles differ from the spectra of ICG in pure water and plasma. We followed the ICG containing liposomal nanoparticle uptake into squamous carcinoma cells (SCC) by fluorescence microscopy and the in vivo uptake into SCC tumors in an orthotopic xenograft nude mouse model under a surgical microscope. Conclusion: Absorption and emission properties of ICG in the different solvent environment, like in plasma and human serum albumin, differ from those in aqueous solution. Photoacoustic spectral imaging confirmed a peak shift towards longer wavelengths and an intensity increase of ICG when bound to the lipids. The SCC cells showed that the ICG containing liposomes bind to the cell surface but are not internalized in the SCC-9 cells after 60 minutes of incubation. We also showed here that ICG containing liposomal nanoparticles can be traced under a surgical camera in vivo in orthotopic SCC xenografts in mice.

Involvement of Shc in insulin- and epidermal growth factor-induced activation of p21ras

1994 ◽  
Vol 14 (3) ◽  
pp. 1575-1581
Author(s):  
G J Pronk ◽  
A M de Vries-Smits ◽  
L Buday ◽  
J Downward ◽  
J A Maassen ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Insulin Receptor ◽  
Tyrosine Phosphorylation ◽  
Egf Receptor ◽  
Growth Factor Receptor ◽  
Nucleotide Exchange ◽  
Similar Time ◽  
Epidermal Growth

Shc proteins are phosphorylated on tyrosine residues and associate with growth factor receptor-bound protein 2 (Grb2) upon treatment of cells with epidermal growth factor (EGF) or insulin. We have studied the role of Shc in insulin- and EGF-induced activation of p21ras in NIH 3T3 cells overexpressing human insulin receptors (A14 cells). A14 cells are equally responsive to insulin and EGF with respect to activation of p21ras. Analysis of Shc immunoprecipitates revealed that (i) both insulin and EGF treatment resulted in Shc tyrosine phosphorylation and (ii) Shc antibodies coimmunoprecipitated both Grb2 and mSOS after insulin and EGF treatment. The induction of tyrosine phosphorylation of Shc and the presence of Grb2 and mSOS in Shc immunoprecipitates followed similar time courses, with somewhat higher levels after EGF treatment. In mSOS immunoprecipitates, Shc could be detected as well. Furthermore, Shc immune complexes contained guanine nucleotide exchange activity toward p21ras in vitro. From these results, we conclude that after insulin and EGF treatment, Shc associates with both Grb2 and mSOS and therefore may mediate, at least in part, insulin- and EGF-induced activation of p21ras. In addition, we investigated whether the Grb2-mSOS complex associates with the insulin receptor or with insulin receptor substrate 1 (IRS1). Although we observed association of Grb2 with IRS1, we did not detect complex formation between mSOS and IRS1 in experiments in which the association of mSOS with Shc was readily detectable. Furthermore, whereas EGF treatment resulted in the association of mSOS with the EGF receptor, insulin treatment did not result in the association of mSOS with the insulin receptor. These results indicate that the association of Grb2-nSOS with Shc may be an important event in insulin-induced, mSOS-mediated activation of p21ras.

In vitro cytotoxic data on Se-methylselenocysteine conjugated to dendritic poly(glycerol) against human squamous carcinoma cells

2021 ◽  
pp. 1-12
Author(s):  
Nicoli Dolores Gonçalves Correa ◽  
Felipe Douglas Silva ◽  
Daniel Perez Vieira ◽  
Carlos Rogerio Soares ◽  
Alvaro Antonio Alencar de Queiroz
Keyword(s):  
Squamous Carcinoma ◽  
Carcinoma Cells ◽  
Squamous Carcinoma Cells

scholarly journals Tyrosine Phosphorylation at a Site Highly Conserved in the L1 Family of Cell Adhesion Molecules Abolishes Ankyrin Binding and Increases Lateral Mobility of Neurofascin

1997 ◽  
Vol 137 (3) ◽  
pp. 703-714 ◽  
Author(s):  
Timothy D. Garver ◽  
Qun Ren ◽  
Shmuel Tuvia ◽  
Vann Bennett
Keyword(s):  
Cell Adhesion ◽  
Tyrosine Phosphorylation ◽  
Adhesion Molecules ◽  
Tyrosine Kinases ◽  
Cell Adhesion Molecules ◽  
Protein Tyrosine Kinase ◽  
Neuroblastoma Cells ◽  
Cytoplasmic Domain ◽  
Lateral Mobility

This paper presents evidence that a member of the L1 family of ankyrin-binding cell adhesion molecules is a substrate for protein tyrosine kinase(s) and phosphatase(s), identifies the highly conserved FIGQY tyrosine in the cytoplasmic domain as the principal site of phosphorylation, and demonstrates that phosphorylation of the FIGQY tyrosine abolishes ankyrin-binding activity. Neurofascin expressed in neuroblastoma cells is subject to tyrosine phosphorylation after activation of tyrosine kinases by NGF or bFGF or inactivation of tyrosine phosphatases with vanadate or dephostatin. Furthermore, both neurofascin and the related molecule Nr-CAM are tyrosine phosphorylated in a developmentally regulated pattern in rat brain. The FIGQY sequence is present in the cytoplasmic domains of all members of the L1 family of neural cell adhesion molecules. Phosphorylation of the FIGQY tyrosine abolishes ankyrin binding, as determined by coimmunoprecipitation of endogenous ankyrin and in vitro ankyrin-binding assays. Measurements of fluorescence recovery after photobleaching demonstrate that phosphorylation of the FIGQY tyrosine also increases lateral mobility of neurofascin expressed in neuroblastoma cells to the same extent as removal of the cytoplasmic domain. Ankyrin binding, therefore, appears to regulate the dynamic behavior of neurofascin and is the target for regulation by tyrosine phosphorylation in response to external signals. These findings suggest that tyrosine phosphorylation at the FIGQY site represents a highly conserved mechanism, used by the entire class of L1-related cell adhesion molecules, for regulation of ankyrin-dependent connections to the spectrin skeleton.

SASS6 promotes proliferation of esophageal squamous carcinoma cells by inhibiting the p53 signaling pathway

2020 ◽  
Author(s):  
Yuanji Xu ◽  
Kunshou Zhu ◽  
Junqiang Chen ◽  
Liyan Lin ◽  
Zhengrong Huang ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Protein Expression ◽  
Signaling Pathway ◽  
Squamous Carcinoma ◽  
Tumor Formation ◽  
Squamous Carcinoma Cells ◽  
P53 Signaling ◽  
P53 Signaling Pathway

Abstract SASS6 encodes for the Homo sapiens SAS-6 centriolar assembly protein and is important for proper centrosome formation. Although centrosomes are amplified in a wide variety of tumor types, abnormally high SASS6 expression had previously only been identified in colon cancer. Moreover, the role of SASS6 in esophageal squamous cell carcinoma (ESCC) pathogenesis has not yet been elucidated. The aim of this study was to investigate the role and mechanisms of SASS6 in ESCC. In this study, we found that the mRNA and protein levels of SASS6 were increased in human ESCC samples. In addition, SASS6 protein expression was associated with the esophageal cancer stage and negatively affected survival of patients with ESCC. Furthermore, silencing of SASS6 inhibited cell growth and promoted apoptosis of ESCC cells in vitro and inhibited xenograft tumor formation in vivo. A genetic cluster and pathway analysis showed that SASS6 regulated the p53 signaling pathway. Western blot demonstrated that CCND2, GADD45A and EIF4EBP1 protein expression decreased and that TP53 protein expression increased after the knockdown of SASS6 in ESCC cells. Therefore, SASS6 promoted the proliferation of esophageal cancer by inhibiting the p53 signaling pathway. SASS6 has potential as a novel tumor marker and a therapeutic target for ESCC.

Upregulation of annexin A5 affects the biological behaviors of lung squamous carcinoma cells in vitro

2014 ◽  
Vol 59 (28) ◽  
pp. 3610-3620 ◽  
Author(s):  
Linlin Gong ◽  
Haoqi Zhao ◽  
Lan Wang ◽  
Bing Sun ◽  
Lijun Yu ◽  
...  
Keyword(s):  
Squamous Carcinoma ◽  
Carcinoma Cells ◽  
Annexin A5 ◽  
Squamous Carcinoma Cells ◽  
Lung Squamous Carcinoma
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