19 research outputs found
Alteration of adhesion molecule expression and cellular polarity in hepatocellular carcinoma
Staining of pancreatic centroacinar cells, liver bile canaliculi and testicular Leydig cells with a monoclonal antibody against adrenocortical cells
Adhesion of carcinoma cells to rat hepatocytes and rat fibronectin is inhibited by the OPAR monoclonal antibody, which is directed against a rat liver-specific carbohydrate epitope
Differential Expression of β-Galactoside α2,6 Sialyltransferase and Sialoglycans in Normal and Cirrhotic Liver and Hepatocellular Carcinoma
Adhesion to the extracellular matrix is positively regulated by retinoic acid in HepG2 cells
Aims: In this work, we aimed to investigate the possible modulation of cell–matrix interactions by retinoic acid (RA), in view of the well-known role of the extracellular matrix (ECM) and integrins in hepatocyte differentiation and proliferation. For this purpose, we analysed the adhesion ability of HepG2 cells on different substrates in the presence and absence of RA evaluating both the expression and cellular localisation of major proteins involved in focal contacts, using Western blot and confocal microscopy. Results: A positive and substratedependent effect of RA on cell–matrix adhesion was observed after long-term culture. The increased adhesiveness in the treated cells was accompanied by an enhanced expression of b1 and a3 integrin subunits, together with a redistribution of b1 receptors clustered at the basal surface. In contrast, the levels of focal adhesion kinase (FAK), paxillin and a-actinin were unchanged, as was the phosphorylation state of FAK. Nonetheless, a stronger association between b1 integrin and intracytoplasmatic proteins of focal contacts was observed in coimmunoprecipitation experiments after RA treatment, suggesting improved connection with the actin cytoskeleton.These results are consistent with previously described antiproliferative and differentiative effects of RA on transformed hepatocytes, and confirm the hypothesis of a direct influence of RA on specific adhesion molecules