THE EXPRESSION OF PROTOONCOGENES IN HUMAN GASTRIC CANCER CELL LINES AND PRIMARY GASTRIC CANCERS DEFINED BY IN SITU HYBRIDIZATION

The expression of several protooncogenes was detected in three different differentiated gastric cancer cell lines (MKN28, MKN45, SGC7901) and 5 specimens from 5 human primary gastric cancers at cellular level by in situ hybridization. The data indicated that there were high levels of c-Ha-ras expression in both cell lines and tumor tissues as compared with control samples. But the transcripts of c-myc and c-erbB were rather low. The results suggested that Ha-ras be involved in or associated with the gastric cancer. There were another two interesting findings: (1) The levels of c-Ha-ras was different among the individual cancer cells within a single gastric cnacer. (2) Some inflammatory cells in the tumor tissuse and normal tissues adjacent to the cancer displayed high level of c-Ha-ras expression. Those two phenomena are worthwhile for further study.