Influence of fixed fibroblasts on glycosaminoglycan synthesis of human gastric carcinoma cells in vitro

The influence of fixed fibroblasts on the glycosaminoglycan (GAG) synthesis of gastric carcinoma cells was examined by incubation along with [3H]glucosamine. In well-differentiated adenocarcinoma cells, the amount of 3H-GAG in the interface material between the carcinoma cells and the fixed fibroblasts was much larger (about twenty times) than in the interface between the carcinoma cells and the bare culture plates, and 3H-GAG consisted mainly of heparan sulfate, with a small amount of dermatan sulfate and chondroitin sulfate. On the other hand, in poorly differentiated carcinoma cells, the amount of 3H-GAG in the interface material produced by the carcinoma cells on the fibroblast was almost the same as on the bare culture dish. In a conventional monolayer culture, well-differentiated adenocarcinoma cells produced a much greater amount of GAG, consisting mainly of dermatan sulfate, chondroitin sulfate and heparan sulfate, than poorly differentiated carcinoma cells. Almost the same amount of hyaluronic acid was secreted into the medium by both types of carcinoma cells.