[Study of genes related to gastric cancer and its premalignant lesions with fluorescent differential display].

BACKGROUND & OBJECTIVE: It is generally recognized that development of gastric cancer arises gradually from premalignant lesions (chronic atrophic gastritis, intestinal metaplasia and dysplasia). Differential display of mRNA is a valuable tool for the identification of differentially expressed genes in human carcinogenesis and development. The search for differentially expressed genes in gastric cancer and its premalignant lesions may help to define molecular alterations in the gastric mucosa tissue that may precede the development of gastric cancer. METHODS: The differentially expressed cDNA bands were isolated and identified by fluorescent differential display in 2 gastric cancer, 2 premalignant lesions, and 2 normal gastric mucosa tissues and then reamplified by PCR. After being cloned, all cDNA fragments were sequenced. Through BLAST software, the sequencing results were compared with GenBank database for homology analysis. Expression of SPTAN1 in 7 gastric cancer tissues, 7 premalignant lesions, and 7 normal gastric mucosa tissues were identified by RT-PCR. RESULTS: Four differentially expressed cDNA fragments were found. Three of them were over-expressed in the gastric cancer tissue. One of them was over-expressed in premalignant lesions and normal gastric mucosa tissue. One cDNA fragment over-expressed in gastric cancer was homologous to SPTAN1 and its over-expression in gastric cancer was confirmed by RT-PCR. The other three cDNA fragments showed significant homology to known gene sequences in GenBank but their functions are unknown. CONCLUSION: Three of the four differentially expressed genes over-expressed in gastric cancer. SPTAN1gene was significantly higher in gastric cancer tissue than in normal gastric mucosa tissue and dysplasia tissue.