Isolation of two novel genes, down-regulated in gastric cancer

Using a differential display technique, we identified two genes that are do wn-regulated in human gastric cancer tissue as compared to normal gastric m ucosa. The down-regulated expression of these genes in gastric cancer tissu e was confirmed by northern blotting analysis and RT-PCR. One, CA11, was a novel gene expressed predominantly in the stomach and was depleted in all o f the gastric cancer cell lines examined. The other gene, GC36, was homolog ous to the digestive tract-specific calpain gene, nCL-4, The expression of both GC36 and nCL-4 was suppressed or depleted in gastric cancer cell lines of differentiated and poorly differentiated types, This is the first repor t of genes, the expression of which is down-regulated with considerable fre quency in gastric cancer.