Aims: Neoangiogenesis is accompanied by an increase in endothelial surface, which can support infiltration by immune cells depending on adhesion molecule expression. Therefore, the expression of cell adhesion molecules on microvessels and epithelial cells was analysed in renal cell carcinomas as compared to tumour-free tissue.
Methods and results: PECAM-1, CD34, ICAM-1, VCAM-1, VLA-4, P- and E-selectin, the macrophage antigens Ki-M1P and Mac-1, and lymphocyte function antigen LFA-1 were identified immunohistochemically. VCAM-1, ICAM-1, and E-selectin were equally or less expressed, whereas P-selectin was increased on microvessels in tumour tissue. The density of VCAM-1-positive tumour microvessels correlated positively with an advanced tumour stage and E- and P-selectin-positive tumour microvessels with the amount of associated macrophages. The expression of ICAM-1 and VCAM-1 on neoplastic epithelia correlated with an increased density of macrophages and a minor degree of tumour differentiation.
Conclusions: The positive correlation of macrophage infiltration and expression of cell adhesion molecules on tumour microvessels and epithelia with minor tumour differentiation and an advanced stage indicates that adhesion molecule expression is not associated with an effective antitumour function of macrophages