Altered expression of proteoglycans in E1A-immortalized rat fetal intestinal epithelial cells in culture

Normal and E1A-immortalized rat fetal intestinal epithelial SLC-11 cells were compared for the characteristics of the 35S-labeled proteoglycans isolated from their cell-associated and secreted fractions. In comparison with control cells in primary culture, immortalized SLC-11 cells: (a) secreted larger amounts of radiolabeled proteoglycans; (b) contained larger amounts of membrane-intercalated proteoglycans, analyzed by hydrophobic affinity chromatography on octyl-Sepharose; (c) produced cell-associated and secreted proteoglycans of smaller hydrodynamic size, assessed by measurement of Kav values; (d) contained a higher percentage of heparan sulfate in the cell-associated proteoglycans, determined by differential susceptibility of glycosaminoglycans to specific glycosaminoglycan lyases; (e) displayed heparan sulfate and chondroitin sulfate with a shorter chain length; and (f) synthesized glycosaminoglycans with a lower degree of sulfation, determined by ion-exchange chromatography. Taken together, these results demonstrate that in E1A-immortalized intestinal epithelial SLC-11 cells, the expression of proteoglycans alters considerably at an early stage of oncogenic transformation.