More recently, from cell biological and biochemical analyses it is clear that cortactin is involved in remodeling the actin cytoskeleton via Arp2/3 mediated actin polymerization, especially its new role in mediating intercellular adhesions and cell spreading [ 35, 37, 38].
These changes are described below: The cadherins are a family of transmembrane proteins that mediate intercellular adhesion via interactions between homotypic proteins on opposing cell surfaces.
These intercellular connections are composed of apical adherens junctions, which mediate intercellular adhesion, and more basal septate junctions (SJ), which are analogous to vertebrate tight junctions and restrict the free diffusion of solutes across epithelia.
Among their major transmembrane components there are proteins which mediate intercellular adhesion, such as different claudin (cldn) isoforms, occludin (ocln), tricellulin and junctional adhesion molecule-A (Tsukita et al., 2001; Ikenouchi et al., 2005; Hartsock and Nelson, 2008; Paris et al., 2008; Anderson and Van Itallie, 2009).
In vitro, intracellular galectin-4 regulates cell proliferation, apoptosis and differentiation, whereas extracellular galectin-4 mediates intercellular adhesion (Huflejt et al., 1997; Huflejt and Leffler, 2003).
E-cadherin is a member of a family of transmembrane glycoproteins that mediate intercellular adhesion [ 3].
We demonstrate frequent abnormalities of expression and function of E-cadherin and catenins, and associated disturbance of E-cadherin-mediated intercellular adhesion in gastric carcinoma cell lines.
Down-regulation of E-cadherin/catenin-mediated intercellular adhesion is known to be an important step in the acquisition of malignancy and metastasis.
Furthermore, these clumps localise FasIII along their flattened common surface (Fig. 5B, arrowheads), a morphology that confirms the homophilic nature of FasIII association and indicates that FasIII mediates intercellular adhesion sufficient to flatten the plasma membrane at these intercellular contacts.
Thus, siRNA-induced depletion of E-cadherin-mediated intercellular adhesion, while promoting a modest increase in cellular invasion, greatly enhances the ability of tamoxifen to induce invasive behaviour in MCF-7 cells.
