Presence of prostaglandin EP(4) receptor gene expression in a rat gastric mucosal cell line

RGM-1 is an epithelial cell line established from gastric mucosa of adult Wistar rats. In this study, we characterized this newly established cell line by Northern blot analysis. We also investigated deoxyribonucleic acid (DNA) synthesis and hexosamine production in RGM-1 by PGE(2). Northern blot analysis did not detect any transcript of proton pump, gastrin receptor, histidine decarboxylase, somatostatin and pepsinogen 1, indicating the absence of characteristics of parietal, ECL, D and chief cells in RGM-1 cells. However, this periodic acid-Schiff (PAS)-positive cell line expressed prostaglandin EP(4) receptor mRNA but not EP(1) and EP(3) receptor mRNAs. [H-3]-thymidine incorporation into DNA of the cells was not increased by PGE(2). In contrast, PGE(2) increased hexosamine content in RGM-1 cells. These results suggest that RGM-1 may be a useful model of gastric mucosal cells and that PGE(2) plays a role on mucin synthesis in RGM-1 cells possibly via EP(4) receptors.