Identification of novel genes from stomach cancer cell lines by differential display

Gastric cancer is a leading cause of cancer death in many parts of the world. None of the tumor markers available to date provide for a reliable screening/diagnostic test. By using differential display technology on gastric cancer nonmetastatic (RF1) and metastatic (RF48) cell lines, we have isolated six novel cDNA clones. Five of them have not been previously identified. However, one of them appears to be the human homolog of the bovine oligomycin sensitivity conferral protein (oscp). Northern blot analysis showed that this clone is expressed at a much higher level in the metastatic (RF48) than the nonmetastatic (RF1) cancer cell line from the same patient. High level expression of the same gene is also observed in the breast cancer cell lines BT20 and T47D. The other five novel clones isolated showed either low or no expression in the RF1 and RF48 gastric cell lines, but variable levels of expression were detectable in breast cancers cell lines and normal tissues.