Effects of Human Interferons and 60Cobalt Radiation on Canine and Feline Tumour Cells–-Preclinical Studies
This study examined the effects of recombinant human interferons (rHuIFN) α 2a, α 2b and γ on canine and feline tumour-cell proliferation and radiosensitivity. Sensitivity of the cell lines to radiation and rHuIFN varied according to the histologic origin of the cells. In radiation experiments, one fraction of 400 cGy produced survival rates of between 76 and 25%. Sensitivity to IFN was higher in cell lines derived from round cell tumours compared to those derived from solid tumors. At doses of 100 and 1000 U/ml IFN α and IFN γ, survival rates of between 70 and 80% were observed. In combined treatment experiments, increase in IFN or radiation dose produced higher cell kills. Increasing the number of fractions had the most pronounced effect. Even small doses of human interferons can have significant effects on animal tumour cells in vitro.