Combined effects of 5-fluorouracil and interferon on proliferation of human neoplastic cells in culture.

The growth inhibitory effects of the combination of 5-fluorouracil (5-FU) and human fibroblast interferon on human neoplastic cell lines and normal human fibroblasts were examined. The neoplastic cell lines used were HeLa (cervical carcinoma), MCF-7 (mammary carcinoma), WI-38 CT-1 (embryonic lung fibroblasts transformed in culture by 60Co gamma-ray irradiation), KMM-1 (myeloma), and Raji (Burkitt's lymphoma). The normal human cell line used was WI-38. The growth inhibitory effects were determined by measuring colony formation for HeLa, MCF-7, WI-38 CT-1, and WI-38 cells, and by measuring cell growth for KMM-1 and Raji cells. Each cell line showed different sensitivities to 5-FU or interferon. The combination of 5-FU and interferon showed synergistic inhibitory effects on the growth of HeLa, WI-38 CT-1, KMM-1, and Raji cells. Neither synergistic nor additive growth inhibitory effects of the combination of 5-FU and interferon were observed in MCF-7 and WI-38 cells.