Immunohistochemical detection of the nm23-H1 protein in gallbladder and biliary tract tumours

Abstract

Nm23-H1 protein immunoreactivity was studied in gallbladder (n=13), common bile duct (n=5) and ampulla tumours (n=7) together with chronic cholecystitis (n=11) and preneoplastic lesions of the gallbladder (n=4) and ampulla (n=3), using the monoclonal antibody, NM 301 (Molecular Oncology Inc.). Absent or weak nm23-H1 immunostaining was found in most (67%) of the poorly differentiated gallbladder adenocarcinomas and in half of the moderately differentiated adenocarcinomas. The difference in nm23-H1 protein immunostaining between gallbladder carcinoma and chronic cholecystitis was statistically significant (<i>p</i>=0.0022; X² test). Significant correlation was found between prolonged patient survival and nm23-H1 expression in gallbladder carcinomas (r=0.652, <i>p</i>=0.0l6, Spearman's rank test). Most gallbladder dysplasias and adenoma had no reduction in nm23-H1 expression. All common bile duct carcinomas, most (67%) ampullary carcinomas <i>in situ</i> and some (43%) ampullary carcinomas had moderate to strong nm23-Hl immunostaining. In summary, low nm23-H1 protein immunoreactivity occured frequently in gallbladder carcinomas and this was associated with reduced patient survival. Differences in nm23-H1 protein immunoreactivity in common bile duct and ampullary carcinomas suggest that these tumours have a different molecular origin to gallbladder cancers.