Characterization of the Antitumor Activities of IFN- α 8 on Renal Cell Carcinoma Cells In Vitro

Abstract

Interferon-α (IFN-α) has a number of therapeutic applications in the treatment of various human cancers and diseases of viral origin. IFN-α includes several subtypes, and little has been reported on the biologic properties of the individual subtypes. Here, we report on the individual antitumor effects of five IFN-α subtypes, α1, α2,α5, α8, and α10, against six renal cell carcinoma (RCC) cell lines in vitro. Among the subtypes, IFN-α8 most potently inhibited cell proliferation and delayed the G₁/S transition. Synergistic induction of apoptosis was shown in two of the RCC cell lines when treated with the combination of IFN-α and IFN-γ rather than with either IFN-α or IFN-γ alone. IFN-α8 was most effective in the induction of apoptosis when combined with IFN-γ. In addition, IFN-α8 had the strongest ability to upregulate HLA class II antigen expression in the subtypes examined. These data indicate that subtypes of IFN-α have disparate antitumor effects in vitro, and in vitro distinctions among the IFN-α subtypes should be appreciated more in clinical application.