Correlation of surface fucopeptide patterns with tumorigenicity of mouse mammary epithelial cells

The plasma membrane fucopeptides of tumorigenic and nontumorigenic mouse mammary epithelial cells were studied. The types of cells analyzed included (a) cell lines derived from mouse mammary carcinomas of varying etiologies (viral, hormonal, chemical carcinogen), (b) a series of clonal cells lines which were nontumorigenic at lower passage levels and tumorigenic at higher passage levels, (c) normal primary cells derived from the mammary glands of pregnant or lactating animals, and (d) primary cells from tumors produced by s.c. injection of cultured mammary tumor cells into syngeneic animals. A distinctive difference was observed in the size distribution of the trypsin-sensitive surface fucopeptides from tumorigenic and nontumorigenic mammary cells; the tumorigenic cells were relatively enriched in the larger fucopeptides. The size distribution of the trypsin-sensitive surface fucopeptides was not markedly influenced by the physiological state of the cells or by cell population density. It appears that the trypsin-sensitive surface fucopeptide size pattern may be a distinguishing characteristic between tumorigenic and nontumorigenic mouse mammary epithelial cells.