Fas/APO-1-mediated apoptosis of human renal cell carcinoma.

We have investigated the Fas-mediated apoptosis of cultured human renal cell carcinoma OUR-10. OUR-10 cells express Fas antigen on their cell surface and showed apoptotic cell death by stimulation with anti-Fas agonistic antibody. Cell proliferation of OUR-10 was reduced to 62% by the addition of anti-Fas antibody. The cytotoxic effect of anti-Fas antibody on OUR-10 was augmented by the pretreatment of these cells with interferon-gamma, not with interferon-alpha or with interleukin-2. Flow cytometry demonstrated that preculture of Our-10 cells with interferon-gamma increased the cell surface Fas antigen. Immunohistochemical analysis of resected tissues from the patients with renal cancer revealed stronger expression of Fas antigen on the surface of cancer cells than that of normal cells. These data suggest that Fas may be one of the possible targets for a novel approach to human kidney cancer, and the efficiency of this Fas-mediated treatment for kidney cancer could be augmented by the treatment with interferon-gamma.