Strong immunofluorescence signals for the mesenchymal marker vimentin were observed in some individual Ctrl-HSC and Arr-HSC cells, but evident differences in these signals could not be detected between the cell lines. To pursue the mechanisms underlying the altered behavior and morphology of Arr-HSC cells we performed measurements using electric cell-substrate impedance sensing, a method that provides quantitative data on cell attachment, spreading and the strength of cell-cell contacts by monitoring changes in the system impedance. The Arr-HSC cells showed markedly SCH772984 higher impedance at a low frequency than the control cells. Also the HSC-3 cells treated with ArrCM showed higher impedance than those treated with CtrlCM. The change in the impedance can be related either to cell inherent dielectric properties, formation of cell-cell junctions or cellsubstrate interactions, and a mathematical ECISTM Model can be applied to distinguish these parameters from each other. Thus, a cell membrane capacitance reflects the structure and folding of cell membrane, a barrier resistance refers to establishment of cell-to-cell junctions, and a cell-substrate interaction parameter a is linearly related to the cell surface area and, inversely, to the distance between cell and substrate. This modeling supported our observations on altered cell morphology and E-cadherin of the Arr-HSC cells. First, significantly increased Rb of the Arr-HSC cells relative to the Ctrl-HSC implied tightening of intercellular junctions. As we did not observe apparent changes in the cell size between the HSC clones by phase contrast microscopy or immunofluorescent stainings, the higher a value of Arr-HSC cells can be attributed to a better cell adhesion to the substratum. Lastly, altered Cm of Arr-HSC cells further Staurosporine points to differences in the cell morphology and cell membrane properties. The signaling through b1 integrin is known to affect E-cadherin dynamics, and cell motility and EMT are abrogated by integrin knockdown. a1b1 integrin was identified as a functional receptor for arresten on endothelial cells, but to date the arresten receptors on carcinoma cells have not been identified. HSC-3 cells express several integrin receptors, including a1b1 and a2b1. We thus performed ECIS experiments with Arr-HSC cells in the presence of functionblocking antibodies for collagen binding integrins a1b1 and a2b1. Administration of integrin a1 antibody decreased the impedance of the Arr-HSC cells while that of the control cells remained unaltered. Incubation of Arr-HSC cells with the integrin a2 blocking antibody almost completely inhibited the cell spreading, but also control cells showed reduced impedance in the presence of this antibody. Control IgG did not have any effect on the behavior of the cells. These data suggest that integrin a1b1 is able to bind arresten also on oral squamous carcinoma cells, resulting in changes in the cell morphology and motility. Tumor growth and metastasis depends on local neovascularization induced by hypoxic conditions and regulated by the tumor microenvironment, including the components of the ECM. Arresten is one of the five thus far identified basement membrane collagen IV-chain-derived fragments that can inhibit angiogenesis and thereby reduce tumor growth via integrin binding. Arresten binds to integrin a1b1 on endothelial cells to regulate the actin cytoskeleton and migration.