ABERRANT EXPRESSION OF C-MET MESSENGER-RNA IN HUMAN GASTRIC CARCINOMAS

We examined mRNA expression for c-met encoding hepatocyte growth facto r receptor in 8 gastric carcinoma cell lines and 31 surgically resecte d gastric carcinoma tissues by Northern-blot analysis. Two forms of th e transcript, sized 7.0 kb and 6.0 kb, were found in gastric carcinoma s. Transcripts of both sizes were detected at various levels in all th e gastric carcinoma cell lines except the MKN-74 line, which expressed only the 7.0-kb form. Of the 31 gastric carcinomas, 15 (48%) over-exp ressed the 7.0-kb transcript when compared with non-neoplastic mucosa. The 6.0-kb transcript of the c-met gene was expressed at considerable levels in 52% of the gastric carcinoma tissues, whereas it was only s lightly expressed in non-neoplastic mucosa of a small number of cases. An important finding was that expression of the 6.0-kb transcript was closely correlated with tumor staging, lymph-node metastasis and dept h of tumor invasion. These results, overall, suggest that the 6.0-kb t ranscript of the c-met gene might participate in the development and p rogression of gastric carcinomas. (C) 1993 Wiley-Liss, Inc.