Adhesion properties of human bladder cell lines with extracellular matrix components: the role of integrins and glycosylation

Integrin subunits present on human bladder cells displayed heterogeneous func­tional specificity in adhesion to extracellular matrix proteins (ECM). The non-malignant cell line (HCV29) showed significantly higher adhesion efficiency to collagen IV, laminin (LN) and fibronectin (FN) than cancer (T24, Hu456) and v-raf transfected (BC3726) cell lines. Specific antibodies to the a2, a5 and β1 integrin sub- units inhibited adhesion of the non-malignant cells, indicating these integrin partici­pation in the adhesion to ECM proteins. In contrast, adhesion of cancer cells was not inhibited by specific antibodies to the β1 integrin subunit. Antibodies to a3 integrin in­creased adhesion of cancer cells to collagen, LN and FN, but also of the HCV29 line with colagen. It seems that a3 subunit plays a major role in modulation of other integrin receptors especially in cancer cells. Differences in adhesion to ECM proteins between the non-malignant and cancer cell lines in response to Gal and Fuc were not evident, except for the v-raf transfected cell line which showed a distinct about 6-fold increased adhesion to LN on addition of both saccharides. .-Acetylneuraminic acid inhibited adhesion of all cell lines to LN and FN irrespective of their malignancy.