EFFECTS OF HUMAN INTERFERONS AND (60)COBA LT RADIATION ON CANINE AND FELINE TUMOR-CELLS - PRECLINICAL STUDIES

This study examined the effects of recombinant human interferons (rHuI FN) alpha 2a, alpha 2b and gamma on canine and feline tumour-cell prol iferation and radiosensitivity. Sensitivity of the cell lines to radia tion 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 lin es derived from round cell tumours compared to those derived from soli d tumors. At doses of 100 and 1000 U/ml IFN alpha and IFN gamma, survi val rates of between 70 and 80% were observed. In combined treatment e xperiments, increase in IFN or radiation dose produced higher cell kil ls. 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.