Expression Pattern of Tumor Endothelial Marker 8 Protein in Gallbladder Carcinomas

Tumor endothelial marker 8 protein (TEM8) is highly specific to tumor angiogenesis and is not required fornormal adult angiogenesis and hence might prove to be a target for anti-angiogenic therapies in the future. Wehere evaluated protein and gene expression patterns in human endothelial cells of benign gallbladder - gallstonediseases (GSDs) and gallbladder carcinomas (GBCs) using immunostaining, immunofluorescence and westernblotting techniques. Subjects comprised 175 GBC patients, 38 males and 137 females, aged 30–85 years (meanage 50.3±13.4 years) and twenty with GSDs, aged 30-75 years, (51.4±10.0 years) for comparison (male 4/20 andfemales 16/20). TEM8 protein expression increased significantly (p<0.0001) with increasing stage of GBC andwas mostly limited to endothelial cells, although there was no significant change with the grade. Interestingly,only 80-85 kDa and 60 kDa isoforms of TEM8 increased significantly whereas 45 kDa isoform was absent inGBCs. Conclusions- These results suggest that TEM8 plays an unknown important biological role to promotetumor angiogenesis in GBC.