CORRELATION BETWEEN OVEREXPRESSION OF C-MET GENE AND THE PROGRESSION OF GASTRIC-CANCER

The c-met oncogene encodes a receptor of hepatocyte growth factor (HGF ), which has both mitogenic and motogenic activities. We have studied the c-met gene expression in gastric cancer by immunohistochemical met hod using an antibody specific to the c-met beta-chain. c-met immunore activity was preferentially localize on the cell membrane, and 55 (43% ) of 127 primary gastric cancers showed c-met immunoreactivity. Strong correlation was found between c-met expression in large tumors, lymph node involvement, serosal invasion, as well as peritoneal disseminati on. Furthermore, c-met positive tumors had a tendency to metastasize t o more distant lymph node sites. Regarding the macroscopic type, Borrm ann type 4 gastric cancer showed the highest incidence (12/16, 76%) of positive c-met expression. Patients with c-met positive tumor ran a s ignificantly poorer prognosis than those with c-met negative one. Thes e results indicate that the c-met protein participates in the progress ion and invasion of stomach cancer, and that c-met tissue status is a useful biological marker in gastric cancer.