Expression of intercellular adhesion molecule‐1 (ICAM‐1) on renal‐cell cancer: Possible significance in host immune responses

In this study we examined the expression of intercellular adhesion molecule-1 (ICAM-1) in 28 cases of renal-cell cancer (RCC). We also examined ICAM-1 expression on RCC cell lines in response to cytokines. Immunohistochemistry revealed frequent expression (23 positive cases among the 28 RCCs) of ICAM-1 in RCC. The molecule was not detected on renal tubular cells as far as could be determined. Furthermore, the number of ICAM-1-positive cells in RCC was significantly correlated with the degree of mononuclear cell infiltration, involving mainly T lymphocytes and a smaller number of macrophages bearing the LFA-1 molecule. Expression of ICAM-1 on RCC cell lines was augmented by in vitro treatment with interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha and interleukin-1 (IL-1)beta. These results suggest that the expression of ICAM-1 on RCC might be modified by cytokines produced by tumor-infiltrating mononuclear cells, and that ICAM-1 expression on RCC might augment the host immune reaction.