Rapid Cloning and Tissue Expressive Analyses of cDNA Fragments in Human Gastric Cancer

Previously,an EST(expression sequence tag) fragment, W123 (Genbank accession No.AF150631) differentially expressed between gastric cancer and normal tissues, was cloned using differential display PCR technique. A few homologous EST sequences were captured when processing similarity search in human EST database. To search for additional W123 homologous genes in gastric tissue, a primer for 3′ RACE(rapid amplification of cDNA end) from highly conserved region among the above ESTs was designed and seven EST fragments with poly(A) tail were cloned. Compared with ESTs in GenBank, the seven EST fragments represented novel genes with a common sequence. Northern blot was applied to detect the expression of these genes between gastric cancer and normal tissues. The results suggested that a combination of bioinformatics and RACE technique is a rapid and effective method for seeking for disease related genes in specific tissue