Search results for "Focal adhesion"
showing 7 items of 37 documents
SAHA/TRAIL combination induces detachment and anoikis of MDA-MB231 and MCF-7 breast cancer cells
2012
Abstract SAHA, an inhibitor of histone deacetylase activity, has been shown to sensitize tumor cells to apoptosis induced by TRAIL, a member of TNF-family. In this paper we investigated the effect of SAHA/TRAIL combination in two breast cancer cell lines, the ERα−positive MCF-7 and the ERα−negative MDA-MB231. Treatment of MDA-MB231 and MCF-7 cells with SAHA in combination with TRAIL caused detachment of cells followed by anoikis, a form of apoptosis which occurs after cell detachment, while treatment with SAHA or TRAIL alone did not produce these effects. The effects were more evident in MDA-MB231 cells, which were chosen for ascertaining the mechanism of SAHA/TRAIL action. Our results show…
Fibronectin-bound α5β1 integrins sense load and signal to reinforce adhesion in less than a second
2017
Integrin-mediated mechanosensing of the extracellular environment allows cells to control adhesion and signalling. Whether cells sense and respond to force immediately upon ligand-binding is unknown. Here, we report that during adhesion initiation, fibroblasts respond to mechanical load by strengthening integrin-mediated adhesion to fibronectin (FN) in a biphasic manner. In the first phase, which depends on talin and kindlin as well as on the actin nucleators Arp2/3 and mDia, FN-engaged α5β1 integrins activate focal adhesion kinase (FAK) and c-Src in less than 0.5 s to steeply strengthen α5β1- and αV-class integrin-mediated adhesion. When the mechanical load exceeds a certain threshold, fib…
Focal adhesions are hotspots for keratin filament precursor formation
2006
Recent studies showed that keratin filament (KF) formation originates primarily from sites close to the actin-rich cell cortex. To further characterize these sites, we performed multicolor fluorescence imaging of living cells and found drastically increased KF assembly in regions of elevated actin turnover, i.e., in lamellipodia. Abundant KF precursors (KFPs) appeared within these areas at the distal tips of actin stress fibers, moving alongside the stress fibers until their integration into the peripheral KF network. The earliest KFPs were detected next to actin-anchoring focal adhesions (FAs) and were only seen after the establishment of FAs in emerging lamellipodia. Tight spatiotemporal …
TGFβ-induced EMT requires focal adhesion kinase (FAK) signaling
2007
The epithelial-to-mesenchymal transition (EMT) is a crucial process, occurring both during development and tumor progression, by which an epithelial cell undergoes a conversion to a mesenchymal phenotype, dissociates from initial contacts and migrates to secondary sites. We recently reported that in hepatocytes the multifunctional cytokine TGFβ induces a full EMT characterized by (i) Snail induction, (ii) E-cadherin delocalization and down-regulation, (iii) down-regulation of the hepatocyte transcriptional factor HNF4α and (iv) up-regulation of mesenchymal and invasiveness markers. In particular, we showed that Snail directly causes the transcriptional down-regulation of E-cadherin and HN…
Extremely low frequency electromagnetic fields (ELF-EMFs) induce in vitro angiogenesis process in human endothelial cells.
2008
Effects of extremely low frequency (ELF) electromagnetic fields (EMFs) on activation of angiogenesis were analysed using cultured umbilical human vein endothelial cells (HUVECs). The cultures were exposed to a sinusoidal EMF to intensity of 1 mT, 50 Hz for up to 12 h. EMFs increased the degree of endothelial cell proliferation and tubule formation, coupled by an acceleration in the process of wound healing. Since this process is physiologically accompanied by a large modification in the structural organization of actin and focal adhesions, we analyzed the rearrangement of some cytoskeleton elements demonstrating a major reorganization of the fibres and of the focal adhesion complexes after …
Cell-cycle control in cell-biomaterial interactions
2000
Current biocompatibility testing involves the demonstration of cell proliferation, which is usually interpreted as a sign of positive biocompatibility when the materials sustain cell proliferation. As the field of biomaterials research is rapidly moving toward tissue-engineered devices and hybrid organs, control of cell function has become a main topic. Cell function, which involves specific differentiation pathways, cannot be separated from cell-cycle control. The study of cell-cycle control is an important extension of routine proliferation assays and has extensive roots in developmental and tumor biology. We studied the expression of the tumour suppressor gene p53 and the proliferation-a…
A DNA‐Encoded FRET Biosensor for Visualizing the Tension across Paxillin in Living Cells upon Shear Stress
2022
Paxillin is a potential participant in the direct intracellular force transmission which is considered as the foundation of cells sensing and responding to extracellular environment. However, the detection of tension across paxillin has not been achieved due to lacking microsized tools. Herein, a paxillin tension sensor (PaxTs) based on Fluorescence Resonance Energy Transfer (FRET) technique was constructed. PaxTs can be expressed and assembled to FA sites spontaneously to visualize the tension across paxillin with FRET efficiency of ~62.4% in living cells. The tension across paxillin was found to decrease upon shear stress, in which the membrane fluidity and contractility of actin acted as…