ESTABLISHMENT AND CHARACTERIZATION OF A HUMAN GASTRIC SCIRRHOUS CARCINOMA CELL-LINE IN SERUM-FREE CHEMICALLY DEFINED MEDIUM

We have established a human gastric scirrhous carcinoma cell line (des ignated as HSC-43) in a serum-free chemically defined medium (CDM) wit hout any polypeptide growth factor, from a primary tumor of a 56-year- old male patient. HSC-43 cells grew in vitro in adherence with a popul ation doubling time of S5 hr, and had the cytological properties of mu cinous epithelial tumor cells. Cytogenetic analysis of the cells revea led pseudotetraploidy, with structural abnormalities of deletion at ch romosome Iq2S and with 3 marker chromosomes. Some cells had retained f eatures of signet-ring cells and caused fibroblastic proliferation whe n transplanted into athymic nude mice. The possible involvement of tra nsforming growth factor-alpha(TGF-alpha), and its receptor, the epider mal-growth-factor receptor (EGFR), on the growth of HSC-43 cells was s tudied. Synthesis and secretion of TGF-alpha by HSC-43 cells were conf irmed by biological assay and enzyme-linked immunosorbent assay. Radio receptor analysis showed the presence of receptors for EGF in HSC-43 c ells. Proliferation of HSC-43 cells was inhibited by antibodies agains t TGF-alpha and/or the EGFR. However, neither TGF-alpha nor epidermal growth factor (EGF) was effective in stimulating the cell growth of HS C-43 cells, irrespective of the cell density when supplemented exogeno usly. Our data suggest that TGF-alpha and EGFR play a role in the auto crine growth of HSC-43 cells. This may be another example of growth re gulation of gastric carcinoma.