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

Abstract

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. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Specificity of antibodies to the purified Con A acceptor glycoproteins of cultured tumour cells

“…It is remarkable that the HeLa cell line which has been in cell culture for several decades (Gey et al, 1952) under poorly controlled conditions should retain the glycoprotein antigen profile of the normal tissue from which it was derived. However these observations are consistent with previous studies showing that the glycoprotein fingerprints of cultured tumour cells do not change during long-term tissue culture (Koch et al, 1983). This suggests a general approach to the classification of tumour cell lines where there is an uncertainty about their origin i.e.…”

“…Since the patterns of variable glycoproteins expressed by cells derived from the same pathway of differentiation are usually similar or even identical (Koch & Smith, 1983) it was concluded that the variable glycoproteins reflect the state of differentiation of the normal precursor cell from which each tumour cell originates. This linkage of the pattern of variable glycoproteins to cell differentiation suggested that they could be of considerable value as markers for the classification of tumours as well as the study of normal differentiation and development.…”

Differences between preneoplastic cells, neoplastic cells and their normal counterparts

“…Glycoconjugate changes have been demonstrated in tnelanoma sublines (86). Similar alterations have been noted in other neoplastic cell lines, sotne are not idiosyncratic variations in that they appear to be indicators of the type of nortnal cell from which the neoplastn arose and, as such, may prove to be of use a markers for the classification of neoplastic cells (87).…”