Membrane glycopeptides from chemically transformed cells: comparison between mesenchymal and epithelial cell lines derived from dimethylnitrosamine-treated rat kidney.

The membrane glycopeptides of normal and chemically transformed malignant cell lines derived from rat kidney were investigated by gel permeation chromatography. The cell lines, which were metabolically labeled with i_-{5,6-3H]fucose or o-[63H]glucosamine, were derived from rats treated in vivo with a carcinogenic dose of dimethylnitrosamine to induce both mesenchymal and cortical epithelial tumors in the rat kidney. Among the cell lines examined were: (a) transformed lines of mesenchymal type derived from the rat kidney 2 to 24 hr after the dose of carcinogen; (o) mesenchymal tumor cell lines obtained from the dimethylnitrosamine-induced mesenchymal tumors occurring at 7 to 10 months; (c) a transformed epithelial cell line derived from rat kidney 48 hr after the carcinogenic dose; and (d) an epithelial cell line obtained from a renal adenocarcinoma induced at 10 months by a dose of diethylnitrosamine. For control comparisons, populations of normal renal epithelium and mesenchyme were cultured selectively from untreated rats. The radioactive glycopeptides of the neoplastic epithelial cell lines (transformed and tumor) displayed a shift to more complex higher-molecular-weight glycopeptides when compared with the normal epithelial counterparts. These results were similar to those reported previously for other cell types. In contrast, the neoplastic cell lines of mesenchymal origin lacked higher-molecular-weight glycopeptides, display ing patterns that were identical with those of normal renal mesenchymal cells. It is suggested from these results that the membrane glycopeptide alterations characteristic of virustransformed and other tumor cells are not detected by these techniques in all cell lines transformed by chemical agents. Furthermore, cell lineage within the same organ may play a role in the observed difference.