Transforming growth factor beta-2 (TGF-B2) is secreted by glioma cells and is known to decrease leukocyte-endothelium interaction. TGF-B2 alone and in conjunction with soluble tumor necrosis factor (TNF) p55 receptor, was found to decrease the expression of TNF induced VCAM-1 on the malignant glioma cell line A-172 and human cerebral microvessel endothelial (CNS-EC) cells. Co-culture of A-172 glioma cells led to a decrease in VCAM-1 expression; this effect on CNS-EC in co-culture could be simulated by glioma supernatant alone. These results suggest that malignant gliomas, by secreting TGF-B2 and releasing soluble TNF receptors, modulate adhesion molecules.