CONTRASTING MIGRATORY RESPONSE OF ASTROCYTOMA-CELLS TO TENASCIN MEDIATED BY DIFFERENT INTEGRINS

Tenascin, an extracellular matrix protein, is expressed in human gliom as in vitro and in vivo, The distribution of tenascin at the invasive edge of these tumors, even surrounding solitary invading cells, sugges ts a role for this protein as a regulator of glioma cell migration, We tested whether purified tenascin, passively deposited on surfaces, in fluenced the adhesion or migration of a human glioma-derived cell line , SF-767, Adhesion of glioma cells to tenascin increased in a dose-dep endent fashion up to a coating concentration of 10 mu g/ml. Higher coa ting concentrations resulted in progressively fewer cells attaching, C ell adhesion could be blocked to basal levels using anti-beta 1 integr in antibodies. In contrast, when anti-alpha v antibodies were added to the medium of cells on tenascin, cell adhesion was enhanced slightly, Using a microliter scale migration assay, we found that cell motility on tenascin was dose dependently stimulated at coating concentrations of 1 and 3 mu g/ml, but migration was inhibited below levels of nonsp ecific motility when tested at coating concentrations of 30 and 100 mu g/ml. Migration on permissive concentrations of tenascin could be rev ersibly inhibited with anti-beta 1, while treatment with anti-alpha v antibodies increased migration rates. We conclude that SF-767 glioma c ells express two separate integrin receptors that mediate contrasting adhesive and migratory responses to tenascin.