Overexpression of intercellular adhesion molecule-1 (ICAM-1) in pancreatic adenocarcinoma in comparison with normal pancreas.

To elucidate the role of intercellular adhesion molecules (ICAMs), which has not been well understood in pancreas, we investigated the localization and expression of ICAM-1 by immunohistochemistry and in situ hybridization (ISH) in pancreatic adenocarcinoma and in normal pancreas. The localizations of ICAM-2 and ICAM-3 were also investigated by immunohistochemistry. In normal pancreas, acinar cells, duct epithelial cells, and Langerhans islet cells failed to stain with anti-ICAM-1, anti-ICAM-2, and anti-ICAM-3 antibodies. These cells showed no expression of ICAM-1 mRNA. On the other hand, various percentages of carcinoma cells were stained with anti-ICAM-1 antibody, while no carcinoma cells were stained with anti-ICAM-2 and anti-ICAM-3 antibodies. ICAM-1 mRNA expression was also observed in carcinoma cells, and ICAM-1 mRNA expression was associated with localization of the ICAM-1 protein. These results suggest that ICAM-1 expression is up-regulated in pancreatic adenocarcinoma cells and that ICAM-1 is involved in malignant processes in pancreas.