Expression of VCAM-1, ICAM-1, E- and P-selectin and tumour-associated macrophages in renal cell carcinoma

Aims: Neoangiogenesis is accompanied by an increase in endothelial surface, which can support infiltration by immune cells depending on adhesion molec ule expression. Therefore, the expression of cell adhesion molecules on mic rovessels and epithelial cells was analysed in renal cell carcinomas as com pared to tumour-free tissue. Methods and results: PECAM-1, CD34, ICAM-1, VCAM-1, VLA-4. P- and E-selecti n, the macrophage antigens Ki-M1P and Mac-1, and lymphocyte function antige n LFA-1 were identified immunohistochemically. VCAM-1, ICAM-1, and E-select in were equally or less expressed, whereas P-selectin was increased on micr ovessels in tumour tissue. The density of VCAM-1-positive tumour microvesse ls correlated positively with an advanced tumour stage and E- and P-selecti n-positive tumour microvessels with the amount of associated macrophages. T he expression of ICAM-1 and VCAM-1 on neoplastic epithelia correlated with an increased density of macrophages and a minor degree of tumour differenti ation. Conclusions: The positive correlation of macrophage infiltration and expres sion of cell adhesion molecules on tumour microvessels and epithelia with m inor tumour differentiation and an advanced stage indicates that adhesion m olecule expression is not associated with an effective antitumour function of macrophages.