scholarly journals Down-regulation of Rap1 activity is involved in ephrinB1-induced cell contraction

2005 ◽  
Vol 389 (2) ◽  
pp. 465-469 ◽  
Author(s):  
Jurgen A. Riedl ◽  
Dominique T. Brandt ◽  
Eduard Batlle ◽  
Leo S. Price ◽  
Hans Clevers ◽  
...  
Keyword(s):  
Tyrosine Kinases ◽  
Small Gtpases ◽  
Receptor Interaction ◽  
Down Regulation ◽  
Colon Cells ◽  
Eph Receptor ◽  
Colon Cell ◽  
Colon Cell Line ◽  
Cell Retraction ◽  
Stimulation Of

Ephrins are cell surface ligands that activate Eph receptor tyrosine kinases. This ligand–receptor interaction plays a central role in the sorting of cells. We have previously shown that the ephrinB–EphB signalling pathway is also involved in the migration of intestinal precursor cells along the crypts. Using the colon cell line DLD1 expressing the EphB2 receptor, we showed that stimulation of these cells with soluble ephrinB1 results in a rapid retraction of cell extensions and a detachment of cells. On ephrinB1 stimulation, the small GTPases Rho and Ras are activated and Rap1 is inactivated. Importantly, when a constitutively active Rap1 mutant was introduced into these cells, ephrinB1-induced retraction was inhibited. From these results, we conclude that down-regulation of Rap1 is a prerequisite for ephrin-induced cell retraction in colon cells.

scholarly journals Arabinoxylan-Based Particles: In Vitro Antioxidant Capacity and Cytotoxicity on a Human Colon Cell Line

Medicina ◽  
2019 ◽  
Vol 55 (7) ◽  
pp. 349 ◽  
Author(s):  
Mayra A. Mendez-Encinas ◽  
Elizabeth Carvajal-Millan ◽  
Agustín Rascón-Chu ◽  
Humberto Astiazarán-García ◽  
Dora E. Valencia-Rivera ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Cell Line ◽  
Human Colon ◽  
Colon Cells ◽  
Antioxidant Power ◽  
Human Colon Cell Line ◽  
Colon Cell ◽  
Colon Cell Line

Background and objectives: Arabinoxylans (AX) can gel and exhibit antioxidant capacity. Previous studies have demonstrated the potential application of AX microspheres as colon-targeted drug carriers. However, the cytotoxicity of AX gels has not been investigated so far. Therefore, the aim of the present study was to prepare AX-based particles (AXM) by coaxial electrospraying method and to investigate their antioxidant potential and cytotoxicity on human colon cells. Materials and Methods: The gelation of AX was studied by monitoring the storage (G′) and loss (G′′) moduli. The morphology of AXM was evaluated using optical and scanning electron microscopy (SEM). The in vitro antioxidant activity of AX before and after gelation was measured using the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. In addition, the effect of AX and AXM on the proliferation of human colon cells (CCD 841 CoN) was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The final G′ and G′′ values for AX gels were 293 and 0.31 Pa, respectively. AXM presented spherical shape and rough surface with a three-dimensional and porous network. The swelling ratio and mesh size of AXM were 35 g water/g AX and 27 nm, respectively. Gelation decreased the antioxidant activity of AX by 61–64 %. AX and AXM did not affect proliferation or show any toxic effect on the normal human colon cell line CCD 841 CoN. Conclusion: The results indicate that AXM could be promising biocompatible materials with antioxidant activity.

scholarly journals Increased ENT2 Expression and Its Association With Altered Purine Metabolism in Different Stages of Colorectal Cancer Cell Lines

2022 ◽  
Author(s):  
Safaa M. Naes ◽  
Sharaniza Ab-Rahim ◽  
Musalmah Mazlan ◽  
Nurul Azmir Amir Hashim ◽  
Amirah Abdul Rahman
Keyword(s):  
Colorectal Cancer ◽  
Cell Lines ◽  
Purine Metabolism ◽  
Hypoxanthine Phosphoribosyl Transferase ◽  
Normal Colon ◽  
Colon Cells ◽  
Potential Marker ◽  
Colon Cell ◽  
Colon Cell Line ◽  
Therapeutic Development

Abstract Background Colorectal cancer (CRC) is one of the most prevalent malignant cancers worldwide. Although the purine metabolism pathway is known to be vital for cancer cells survival mechanism, not much is known on ENT2 role in CRC development and its association with purine metabolites. Hence this study is aimed to determine the level of hypoxanthine phosphoribosyl transferase (HPRT), hypoxanthine, uric acid (UA), and the activity of xanthine oxidase (XO) and relate the findings with the ENT2 expression level in different CRC stages. Methods and results Normal colon cell line; CCD-841CoN and a panel of human CRC cell lines; SW480, HCT15 and HCT116, representing different CRC stages; Dukes’ B, C, and D respectively, have been used to measure HPRT, hypoxanthine/xanthine, UA levels and the activity of XO by biochemical assays. The level of ENT2 gene expression was also performed by qRT-PCR. The levels of HPRT, hypoxanthine were significantly higher (P< 0.05), while XO and UA were lower (P< 0.05) in all CRC stages as compared to the normal colon cells. Furthermore, ENT2 expression was found to be increased in all CRC stages. Despite having the highest level of HPRT and hypoxanthine, ENT2 level is lower in Dukes' D when compared to Dukes' B and C. Conclusion The rate of salvage pathway is increased in CRC development as indicated by the elevated levels of HPRT and hypoxanthine in different CRC stages. Increase ENT2 expression implies its importance in assisting hypoxanthine uptake. This step is vital in order to increase DNA synthesis via hypoxanthine recycling. Thus, ENT2 may be a potential marker in therapeutic development.

scholarly journals Oxidative stress induced by tBHP in human normal colon cells by label free Raman spectroscopy and imaging. The protective role of natural antioxidants in the form of β-carotene

RSC Advances ◽  
2021 ◽  
Vol 11 (27) ◽  
pp. 16419-16434
Author(s):  
B. Brozek-Pluska ◽  
K. Beton
Keyword(s):  
Oxidative Stress ◽  
Natural Antioxidants ◽  
Protective Role ◽  
Label Free ◽  
Normal Colon ◽  
Stress Injury ◽  
Colon Cells ◽  
Colon Cell ◽  
Colon Cell Line ◽  
Β Carotene

The present study aimed to investigate the protective effect of β-carotene on the oxidative stress injury of human normal colon cell line CCD-18Co triggered by tert-butyl hydroperoxide (tBHP).

scholarly journals Co-operative Cdc42 and Rho signalling mediates ephrinB-triggered endothelial cell retraction

2007 ◽  
Vol 404 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Gillian Groeger ◽  
Catherine D. Nobes
Keyword(s):  
Rho Kinase ◽  
Receptor Activation ◽  
Atpase Inhibitor ◽  
Complex Interplay ◽  
Eph Receptor ◽  
Actomyosin Contractility ◽  
Endothelial Cell Retraction ◽  
Rock Inhibition ◽  
Cell Retraction ◽  
Stimulation Of

Cell repulsion responses to Eph receptor activation are linked to rapid actin cytoskeletal reorganizations, which in turn are partially mediated by Rho–ROCK (Rho kinase) signalling, driving actomyosin contractility. In the present study, we show that Rho alone is not sufficient for this repulsion response. Rather, Cdc42 (cell division cycle 42) and its effector MRCK (myotonic dystrophy kinase-related Cdc42-binding kinase) are also critical for ephrinB-induced cell retraction. Stimulation of endothelial cells with ephrinB2 triggers rapid, but transient, cell retraction. We show that, although membrane retraction is fully blocked by blebbistatin (a myosin-II ATPase inhibitor), it is only partially blocked by inhibiting Rho–ROCK signalling, suggesting that there is ROCK-independent signalling to actomyosin contractility downstream of EphBs. We find that a combination of either Cdc42 or MRCK inhibition with ROCK inhibition completely abolishes the repulsion response. Additionally, endocytosis of ephrin–Eph complexes is not required for initial cell retraction, but is essential for subsequent Rac-mediated re-spreading of cells. Our data reveal a complex interplay of Rho, Rac and Cdc42 in the process of EphB-mediated cell retraction–recovery responses.

scholarly journals Targeting the hallmarks of cancer: the effects of silibinin on proliferation, cell death, angiogenesis, and migration in colorectal cancer

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Saba Sameri ◽  
Chiman Mohammadi ◽  
Mehrnaz Mehrabani ◽  
Rezvan Najafi
Keyword(s):  
Annexin V ◽  
Anticancer Activities ◽  
Scratch Assay ◽  
Anti Cancer ◽  
Different Types ◽  
Colon Cell ◽  
Colon Cell Line ◽  
And Migration ◽  
Induced Apoptosis ◽  
Colony Forming Assay

Abstract Background Silibinin, as a chemopreventive agent, has shown anti-cancer efficacy against different types of cancers. In the present study, we investigated the anti-cancer activities of silibinin on CT26 mouse colon cell line. Methods CT26 cells were treated with different concentrations of silibinin. To examine the cytotoxic effect of silibinin on proliferation, apoptosis, autophagy, angiogenesis, and migration, MTT, colony-forming assay, Annexin V/PI flow cytometry, RT-qPCR, and Scratch assay were used. Results Silibinin was found to significantly reduce CT26 cells survival. Furthermore, silibinin strongly induced apoptosis and autophagy by up-regulating the expression of Bax, Caspase-3, Atg5, Atg7 and BECN1 and down-regulating Bcl-2. Silibinin considerably down-regulated the expression of COX-2, HIF-1α, VEGF, Ang-2, and Ang-4 as well as the expression of MMP-2, MMP-9, CCR-2 and CXCR-4. Conclusions The present study revealed that silibinin shows anticancer activities by targeting proliferation, cell survival, angiogenesis, and migration of CT26 cells.

scholarly journals The Expression of the Cancer-Associated lncRNA Snhg15 Is Modulated by EphrinA5-Induced Signaling

2021 ◽  
Vol 22 (3) ◽  
pp. 1332
Author(s):  
Daniel Pensold ◽  
Julia Gehrmann ◽  
Georg Pitschelatow ◽  
Asa Walberg ◽  
Kai Braunsteffer ◽  
...  
Keyword(s):  
Tyrosine Kinases ◽  
Intracellular Signaling ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Membrane Receptors ◽  
In Vitro Assays ◽  
Eph Receptor ◽  
Medulloblastoma Cell Line ◽  
And Migration

The Eph receptor tyrosine kinases and their respective ephrin-ligands are an important family of membrane receptors, being involved in developmental processes such as proliferation, migration, and in the formation of brain cancer such as glioma. Intracellular signaling pathways, which are activated by Eph receptor signaling, are well characterized. In contrast, it is unknown so far whether ephrins modulate the expression of lncRNAs, which would enable the transduction of environmental stimuli into our genome through a great gene regulatory spectrum. Applying a combination of functional in vitro assays, RNA sequencing, and qPCR analysis, we found that the proliferation and migration promoting stimulation of mouse cerebellar granule cells (CB) with ephrinA5 diminishes the expression of the cancer-related lncRNA Snhg15. In a human medulloblastoma cell line (DAOY) ephrinA5 stimulation similarly reduced SNHG15 expression. Computational analysis identified triple-helix-mediated DNA-binding sites of Snhg15 in promoters of genes found up-regulated upon ephrinA5 stimulation and known to be involved in tumorigenic processes. Our findings propose a crucial role of Snhg15 downstream of ephrinA5-induced signaling in regulating gene transcription in the nucleus. These findings could be potentially relevant for the regulation of tumorigenic processes in the context of glioma.

scholarly journals In vitro guidance of retinal ganglion cell axons by RAGS, a 25 kDa tectal protein related to ligands for Eph receptor tyrosine kinases

Cell ◽  
1995 ◽  
Vol 82 (3) ◽  
pp. 359-370 ◽  
Author(s):  
Uwe Drescher ◽  
Claus Kremoser ◽  
Claudia Handwerker ◽  
Jürgen Löschinger ◽  
Masaharu Noda ◽  
...  
Keyword(s):  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Retinal Ganglion ◽  
Eph Receptor

scholarly journals A new ephrin-A1 isoform (ephrin-A1b) with altered receptor binding properties abrogates the cleavage of ephrin-A1a

2004 ◽  
Vol 379 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Eivind F. FINNE ◽  
Else MUNTHE ◽  
Hans-Christian AASHEIM
Keyword(s):  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Transcript Level ◽  
Binding Properties ◽  
Eph Receptor ◽  
Cleavage Process ◽  
293 Cells ◽  
Significant Expression ◽  
Isoform B ◽  
Epha Receptor

Ephrins are ligands for the Eph receptor tyrosine kinases, which play important roles in patterning nervous and vascular systems. Ephrin-A1 is a glycosylphosphatidylinositol-anchored ligand that binds to the EphA receptor tyrosine kinases. In the present study, we have identified a new ephrin-A1 isoform, denoted ephrin-A1b (ephrin-A1 isoform b). Compared with the originally described ephrin-A1 sequence, ephrin-A1a [Holzman, Marks and Dixit (1990) Mol. Cell. Biol. 10, 5830–5838], ephrin-A1b lacks a segment of 22 amino acids (residues 131–152). At the transcript level, exon 3 is spliced out in the transcript encoding ephrin-A1b. Transfection of HEK-293T cells (human embryonic kidney 293 cells) with an ephrin-A1b-expressing plasmid resulted in a significant expression of the protein on the cell surface. However, soluble EphA2 receptor (EphA2-Fc) bound weakly to ephrin-A1b-expressing transfectants, but bound strongly to ephrin-A1a-expressing transfectants. Ephrins have been shown to undergo regulated cleavage after interaction with their receptors. This process is inhibited by co-expression of ephrin-A1a and ephrin-A1b, indicating that ephrin-A1b influences the cleavage process. Taken together, these findings indicate that this newly described isoform may regulate the function of its ephrin-A1a counterpart.

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