Aprotinin induces surface changes in malignant cells in culture: a possible mode of antitumour action.

Treatment of TRES cells with aprotinin (Trasylol) produced marked changes in their surface properties. There was a concentration-dependent increase in the surface charge density of the cells. The agglutinability of the cells was inhibited by the antiproteinase. The cells became less adhesive to concanavalin A-linked plates. The adhesion of treated TRES cells appeared to be mediated by lectin receptors with lower specificity for concanavalin A. These observations and an analysis of the kinetics of adhesion have suggested the possibility that a new class of concanavalin A receptors appears on the surface of aprotinin-treated TRES cells, which might increase immunogenicity of the cells.