IDENTIFICATION OF A TUMOR-SPECIFIC DETERMINANT ON NEOPLASTIC CELL SURFACES

The phenomena of invasion and metastasis may well depend largely on the chemical structure of malignant cell membranes. The work of Abercrombie, Ambrose, Weiss,1 and others seems to leave little doubt that a change of the properties of the cell surface is responsible for loss of contact inhibition, as seen in the viral or chemical transformation from normal to neoplastic cells. Pardee has suggested that such a difference in the surface structure may also be instrumental in deranging control mechanisms, in particular the control of cell division, by modifying the permeation of regulatory substances.2 A lipase preparation from wheat germ was found by Aub3 to agglutinate malignant cells exclusively. A few exceptions were later found by Aub and co-workers,4 but this agglutination still seems to be a quite specific process for neoplastic cells. Heat resistance and periodate sensitivity of the wheat germ preparation led these authors to think that agglutination was not due to an enzymatic action of the lipase but rather to a mucopolysaccharide existing as an impurity in the lipase preparation. The isolation and characterization of this agglutinin as a pure glycoprotein will be described in this paper. Furthermore, it will be demonstrated that the tumorspecific surface site that interacts with the agglutinin contains N-acetyl-glucosamine (GlcNAc).