Maspin expression in human gastric adenocarcinoma

Maspin, a member of the serpin family of protease inhibitors, is known to be a tumor suppressor. The relationship between its expression and biological significance in various human cancers has not been elucidated. We studied maspin expression in 30 cases of human gastric adenocarcinoma using immunohistochemistry and reverse transcription-polymerase chain reaction. Twenty-seven cases (90%) of gastric adenocarcinoma, regardless of histological type, and all the cases of gastric epithelial cells with intestinal metaplasia (GECIM) showed diffuse and strong immunoreactivity for maspin. Eighteen of 26 cases (69.2%) of non-metaplastic, non-carcinoma gastric epithelia (NMNCE) showed weak and focal immunoreactivity. The level of maspin expression was higher in the GECIM and lower in the NMNCE than in the adenocarcinoma cases. Maspin mRNA expression was detected in all the samples from non-carcinoma mucosa and gastric adenocarcinoma, and was higher in the gastric adenocarcinoma than in the non-carcinoma mucosa (P < 0.001). The lower carcinoma/non-carcinoma mRNA expression rate correlated to the underexpression of maspin immunohistochemistry (P < 0.001). These data suggest that maspin may contribute to gastric carcinogenesis. In addition, immunohistochemical expression of maspin seems to reflect mRNA expression.