Rosiglitazone suppresses gastric carcinogenesis by up-regulating HCaRG expression.

Our previous study demonstrated that PPARgamma ligand rosiglitazone prevents gastric carcinogenesis in rats induced by chemical carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). In this study, we attempted to identify novel anti-cancer mechanisms of rosiglitazone. By examining the gene expression profiles of MNNG-induced and rosiglitazone-treated gastric cancer with Uniset Rat I Bioarray microarray, we identified a gene that showed prominent responses in the rosiglitazone-treated group. The hypertension-related, calcium-regulated gene (HCaRG) was significantly up-regulated in rat gastric carcinoma of the rosiglitazone-treated group when compared with the MNNG group. We further examined HCaRG expression in human gastric cancer and found that the expression of HCaRG was down-regulated in human gastric cancerous tissue. Rosiglitazone markedly induced the expression of HCaRG in the AGS cell line. The up-regulation of HCaRG may be one of the mechanisms underlying the chemopreventive effect of rosiglitazone in gastric cancer.