Intercellular adhesion molecule-3 on endothelial cells. Expression in tumors but not in inflammatory responses.

Intercellular adhesion molecule-3 (ICAM-3) was identified as the third counter-receptor for lymphocyte function-associated antigen-1. ICAM-3 is absent on endothelial cells in normal tissues but found on endothelial cells in lymphomas. Here, we examined ICAM-3 expression on vascular endothelial cells in lymphomas, nonlymphoid malignancies, benign tumors, and inflammatory diseases. We compared the expression of ICAM-3 on endothelial cells with the severity of inflammatory infiltrates and with the presence of E-selectin and VCAM-1. We found that ICAM-3 expression on endothelial cells was high on both benign and malignant tumors whereas it was low in inflammatory diseases. In contrast to E-selectin, ICAM-3 expression on endothelial cells was not correlated to the severity of inflammatory infiltrates. In hemangiomas, we showed by Northern blot analysis and immunocytochemistry that ICAM-3 expression was induced and that it was localized in immature areas that sustain the early stages of angiogenesis. Therefore, expression of ICAM-3 on blood vessels does not seem to play a role in the recruitment of leukocytes during inflammation but rather is correlated with angiogenesis and tumor development.