Concanavalin A acceptor glycoproteins: a new type of marker for the classification of tumour cells.

The Con A acceptor glycoproteins of murine and human tumour cell lines revealed by two-dimensional fingerprinting on polyacrylamide gels fall into two main categories: constant glycoproteins expressed by all cell lines and variable glycoproteins which are only expressed by particular tumour cell lines. Since the number of variable glycoproteins on a typical fingerprint is 50, fingerprints from different cell lines are readily distinguishable. However the variable glycoproteins are not expressed idiosyncratically and cell lines derived from similar classes of tumours express similar patterns of the variable glycoproteins. For example, murine fibrosarcomas express patterns which are virtually identical with one another. Characteristic patterns are also expressed by murine macrophage tumour lines, human carcinomas and human B lymphoblastoid cells. Thus, the variable glycoproteins behave as a set of linked markers which are indicators of the type of normal pre-neoplastic precursor cell from which a tumour is derived and appear to be a new type of marker for tumour cell classification. Antibodies to these glycoproteins could prove useful in tumour localisation and diagnosis.