Comparison of the antitumor effects of human natural and recombinant interferons (alpha and beta) on human cancer cell lines.

The antitumor effects of 5 different subtypes of human type I interferons (IFN-alpha(Le), rIFN-alpha A, rIFN-alpha D, IFN-beta, and rIFN-beta) were studied on 3 human cancer cell lines (Daudi lymphoma, PLC/PRF/' hepatoma, and G361 melanoma). IFN-alpha(Le) was the most potent against Daudi cells. The effects of IFNs were cytostatic. On the other hand, 500 IU/ml of IFN-alpha(Le), IFN-beta and 5000 IU/ml of rIFN-beta showed cytocidal effect against PLC/PRF/5 cells. The G361 cells were the least sensitive to the IFNs tested. This is the first report on the antitumor effect of rIFN-beta isolated from insect cells. The effect of this rIFN-beta was similar to that of IFN-beta.