[Genome-wide association study of gastric cancer and GeMDBJ database]

A genome-wide association study on diffuse-type gastric cancer identified the PSCA gene, whose exact function in the gastric epithelium has been unknown. Immunohistochemical analysis revealed that PSCA is expressed in the region in which gastric epithelial stem cells and precursors are considered to reside. Moreover, the PSCA was downregulated in gastric cancer tissues, and its product showed a cell-growth inhibition activity in vitro. We also identified a functional SNP, the risk allele of which suppressed a promoter activity of the PSCA gene. These findings suggest that the PSCA may contribute to carcinogenesis through the cell-growth regulation of the gastric epithelial precursors. The summary statistics of the 2-stage genome scan is available from a database, GeMDBJ (http://gemdbj.nibio.go.jp/).