An experimental study on the fibrosis of scirrhous gastric carcinoma

9 surgical specimens of gastric carcinoma were examined for their immunoreactivity with type I procollagen antiserum. For specimens of the four Borrmann type IV carcinomas and one of Borrmann type III carcinomas, all of which exhibited abundant fibrous stroma (histologically scirrhous), the cytoplasm of the tumor cells was strongly positive. In contrast, the tumor cells of the non-scirrhous carcinoma (histologically medullary) were poorly reactive to type I procollagen antiserum. We found the cells, which were established from scirrhous carcinoma (KATO III), express type I procollagen mRNA (4.8kb, 6.0kb) as revealed by dot blot analysis and Northern blot hybridization. And we determined the presence of type I procollagen related antigen in the cell culture medium of KATO III using RIA and Western blotting. Administration of glucocorticoid to KATO III caused decrease of procollagen mRNA expression. It was revealed that collagen synthesis of scirrhous gastric carcinoma was regulated by glucocorticoid in the same manner of fibroblast.