| Abstract: | Human malignant melanoma cell lines characterized by either a high or a low ability to grow subcutaneously in athymic nude mice have been examined for their cell-surface glycoproteins. Striking differences were demonstrated between these 2 groups. Cells from lines of low tumorigenicity (LT group) displayed twice as much Vibrio cholerae neuraminidase and galactose oxidase accessible glycoproteins as cells from lines of high tumorigenicity (HT group) and each group of cell lines could be characterized by specific glycoprotein profiles. LT and HT group cells displayed similar amounts of periodate accessible glycoproteins, but sialoglycoprotein profiles were characteristic for each group of cell lines. Furthermore, whereas 87% of the sialic acid released by V. cholerae neuraminidase came from cell surface glycoproteins in HT group cells, only 53-55% of the released sialic acid came from surface glycoproteins in LT group cells. These results suggest that human melanoma cell lines exhibiting different tumorigenicity in nude mice can also be characterized by differences in composition and organization within the plasma membranes of their cell-surface sialoglycoproteins. |
