Expression of hGC-1 is correlated with differentiation of gastric carcinoma

The human G-CSF-stimulated clone-1 (hGC-1) gene encodes a 510-amino acid olfactomedin-related glycoprotein whose exact in vivo localization and function still remain elusive. The aim of this study was to demonstrate hGC-1 protein localization in the normal human gastrointestinal tract and to explore further a potential relationship between hGC-1 expression and gastric carcinoma.

A specific hGC-1 polyclonal antibody raised against purified hGC-1 protein was developed and characterized. Using immunohistochemistry, it was demonstrated that hGC-1 is expressed in the oesophagus, stomach, small intestine and colon. The expression pattern of hGC-1 protein in 173 cases of gastric carcinoma was investigated and a striking correlation was demonstrated between hGC-1 expression and histological type and differentiation of gastric carcinoma. Enhanced hGC-1 expression was more frequently seen in intestinal-type adenocarcinoma, whereas loss of expression tended to occur in the diffuse type. hGC-1 was highly expressed in well or moderately differentiated cancers and was remarkably reduced or lost in poorly differentiated or undifferentiated tumours.

These investigations have defined for the first time the expression pattern of hGC-1 in the normal human gastrointestinal tract and provide a novel and sensitive marker for the differentiation of gastric carcinoma.