Expression of MUC Gene Proteins in Cholecystitis, Adenoma and Adenocarcinoma of the Gallbladder

ABSTRACT

PURPOSE: Normal gallbladder mucosa shows unique and diverse patterns of mucin genes, and altered mucin expressions have been noted in the gallbladders with stones, dysplasia or carcinomas. The aim of this study was to characterize the expressions of MUC gene proteins in cholecystitis, adenoma and adenocarcinoma of the gallbladder. Differences of MUCs expressions according to the histopathologic parameters in gallbladder carcinomas were also studied. METHODS: Three tissue microarray blocks were made from 23 cases of cholecystitis, 40 cases of gallbladder adenoma, and 66 cases of gallbladder adenocarcinoma. Immunohistochemical stains for MUC1, MUC2, MUC4, MUC5AC and MUC6 were performed, and staining intensity and patterns were evaluated. RESULTS: MUC1, MUC2, MUC4, MUC5AC and MUC6 were overexpressed in 86 (66.7%), 20 (15.5%), 68 (52.7%), 74 (57.4%) and 47 (36.4%) of gallbladder lesions, respectively. MUC1 and MUC2 overexpression rates were higher in gallbladder carcinoma than in cholecystitis and gallbladder adenoma (P<0.05). MUC6 overexpression rate was higher in gallbladder adenoma than in cholecystitis and gallbladder carcinoma (P<0.05). Overexpression of MUC4 and MUC5AC showed no significant differences in cholecystitis, gallbladder adenoma and gallbladder carcinoma. In gallbladder carcinomas MUC1 overexpression rate was high in cases with deeper tumor invasion (P<0.05). MUC6 overexpression rate decreased in cases with larger tumor (P<0.05), higher histologic grade (P=NS), and deeper invasion (P=NS). MUC2, MUC4 and MUC5AC overexpression rates had no relations to the histopathologic parameters. CONCLUSION: Carcinomatous change of gallbladder may be related to MUC1 and MUC2 overexpressions. MUC1 overexpression seems to be related to aggressive biologic behavior of gallbladder carcinoma. MUC6 overexpression acts as a good prognostic factor.