The anti-tumor activities of interferon (IFN)-alpha in chronic myelogenous leukaemia (CML)-derived cell lines depends on the IFN-alpha subtypes.

Here we report on the anti-tumor effects of five interferon (IFN)-alpha subtypes, alpha1, alpha2, alpha5, alpha8, and alpha10 in chronic myelogenous leukaemia (CML)-derived cell lines. All of the CML cells can respond to IFN-alpha although the anti-tumor effects of IFN-alpha depend on the target cell and on the type of IFN-alpha subtype used. Proliferation assays showed that IFN-alpha8 was substantially more effective than the other four IFN-alpha subtypes. IFN-alpha8 was the most potent at upregulating immunomodulatory molecule expression while IFN-alpha1 was least potent. These data indicate in vitro distinctions between IFN-alpha subtypes that should be appreciated more in the clinic.