[Combined effect of interferons alpha, beta and gamma on tumor growth in vitro]

The antiproliferative effect of human recombinant interferon alpha, beta and gamma was studied in vitro in combination. Growth of human gastric cancer cell lines and a pancreatic cancer cell line was inhibited markedly by combination of interferons beta and gamma or a combination of all three interferon types. Combination of low-dose interferons (50-100 units/ml) was more effective than a high dose of single interferon. Moreover, human pancreatic cancer cells were completely eliminated after incubation with 5-fluorouracil (0.001 microgram/ml) or methotrexate (0.1 microgram/ml) combined with interferons beta and gamma (50 units/ml each). These results suggested that combination of interferons beta and gamma could be the most effective interferon therapy for cancer.