Cyclooxygenase expression in the gallbladder

The COX expressions were evaluated separately in the epithelium and in the stroma of gallbladder cancer, chronic cholecystitis, xanthogranulomatous ch olecystitis (XGC) and the normal gallbladder. In normal gallbladder COX-2 e xpression rate was significantly higher in the epithelium than in the strom a. The COX-2 expression rate in the epithelium of non-cancerous adjacent ep ithelium to cancerous lesion was significantly lower than those not only of cancer, but also chronic cholecystitis, XGC and normal gallbladder. In str oma, the COX-2 expression rate in cancer, chronic cholecystitis and XGC wer e significantly higher than that of the normal gallbladder. The rate in non -cancerous adjacent stroma to cancer is significantly lower than that of ca ncer and XGC. However, the difference of rate between of normal and of chro nic cholecystitis was not significant. The COX-2 expression rates were sign ificantly higher in both the epithelium and the stroma in the well and mode rately differentiated cancer group than in the poorly and undifferentiated cancer group. Our results suggest that COX-2 expression in the gallbladder may be regulated by various factors and not directly related to carcinogene sis. The significance of its repression in the noncancerous adjacent tissue to cancer lesion should be reevaluated.