A COMPARISON OF THE PROTOONCOGENES BETWEEN THE HUMAN GASTRIC CANCEROUS AND NORMAL MUCOSAL TISSUES

The allelic distribution of EcoRI and BamHI fragments of ras family genes between the human primary gastric cancer tissues and the corresponding adjacent normal tissues did not show any differences. Three genotypes of BamHI restriction fragment length polymorphism of c-H-ras were revealed. No significant differences in the RFLPs were observed between normal individuals and gastric cancer patients. Four protooncogenes, c-H-ras, N-ras, c-myc and c-fos, were found to be transcriptionally active in the gastric cancer tissues in some cases examined. The comparison of the expression of these oncogenes between the malignant tissues and the corresponding normal tissues showed differential patterns. The expression of c-H-ras at cellular level was detected by in situ hybridization. The enhanced expression of c-H-ras in the gastric cancer cells was demonstrated, but the degree of the expression among the cancer cells was shown to be heterogeneous. In addition, the enhanced expression of c-H-ras was seen in the inflammatory cells.