Abstract
c-erbB-2 oncogene has been reported to be frequently amplified in differentiated, tubular type of gastric cancer. Here we report a human gastric cancer which bore co-amplified c-myc and c-erbB-2 oncogenes: a portion of the amplified c-erbB-2 oncogene was found to be rearranged. Furthermore, c-myc and c-erbB-2 oncogenes were over-expressed in the tumor cells. In contrast to the previous reports, this gastric adenocarcinoma was classified as a poorly differentiated type, and was highly tumorigenic in nude mice. These results might suggest that activated c-myc and c-erbB-2 oncogenes co-operate and influence the malignant state of some gastric carcinomas.