[Down-regulated full-length novel gene GDDR and its effect on gastric cancer]

To clone gene fragments from suppression substructive library established for screening down-regulated genes in gastric carcinoma, and obtain the full-length novel gene.

Gene fragments were identified by sequencing plasmids of positive colonies chosen randomly. One gene fragment was amplified by RACE, and the full-length novel gene was obtained. Expression of novel gene mRNA was respectively detected by semi-quantitative PCR in the gastric carcinoma tissues and counterpart normal gastric mucous membrane of 25 patients with gastric cancer. The structure of the full-length novel gene, location on chromosome, property of protein encoded by full-length novel gene and its function were investigated by Bio-message technique.

One 331 bp gene fragment was cloned, and its full-length novel gene obtained by RACE. The novel full-length gene was named GDDR, registered in the number of AF494509 by GenBank. Significant down-regulated expression of GDDR gene mRNA in gastric carcinoma tissues was confirmed (GDDR/beta-actin 13.474 +/- 5.059 vs 1.041 +/- 0.202, P < 0.01). GDDR was located in chromosome 2p13 with 5 exons. As one member of new BRICHO family as CA11, GDDR encoding protein with transmembrane peptide revealed homology to protein encoded by CA11.

A novel full-length gene GDDR is obtained. GDDR likely is another gene of BRICHO family related to gastric cancer.