Comparison of Growth Inhibiting Effect of Natural and Recombinant Interferon-α on Human Osteosarcomas in Nude Mice

Abstract

Of five tested human osteosarcoma xenografts growing in nude mice, two could be growth-arrested by both natural interferon-α (nIFN-α) and recombinant IFN-α2c (rlFN-α2c). The other three less sensitive xenografts could only be partly growth-inhibited by the nIFN-α while no effect was seen with rIFN-α2c. The leukocyte-derived IFN, thus, appeared to have higher antitumor activity per antiviral unit than the recombinant-produced IFN. It is questionable whether this observed difference is of practical relevance for clinical trials employing different IFN-α preparations.