Synergistic antitumor effects of natural human tumor necrosis factor-alpha and natural human interferon-alpha or -gamma on human cancer cell lines.

This study was conducted to assess the enhanced antitumor effects of natural human tumor necrosis factor alpha (nHuTNF-alpha) and natural human interferon alpha or gamma (nHuIFN-alpha or -gamma), in combination, on ten human cancer cell lines. The cell lines tested were colon cancer (RPMI4788), lung cancer (PC10), gastric cancer (MKN-1 and MKN-28), nasopharyngeal cancer (KB), leukemia (K562), lymphoma (Daudi), Liver cancer (H-7) and breast cancer (ZR-75-30 and ZR-75-1). A mixture of nHuTNF-alpha and nHuIFN-alpha (1:1, by unit) showed cytotoxic effects on nHuTNF-alpha resistant cell lines such as RPMI4788, KB and Daudi or nHuIFN-alpha resistant cell lines such as KB, and ZR-75-1, as well as on nHuTNF-alpha or nHuIFN-alpha sensitive cells. A synergistic antitumor effect occurred in four cell lines (RPMI4788, PC10, Daudi and ZR-75-1) treated with a combination of nHuTNF-alpha and nHuIFN-alpha. Also, a combined treatment with nHuTNF-alpha and nHuIFN-gamma (1:1/100, by unit) showed cytotoxic effects on nHuTNF-alpha or nHuIFN-gamma resistant cell lines such as MKN-1, MKN-28, Daudi, H-7 and ZR-75-1. A synergistic antitumor effect occurred in eight cell lines (RPMI4788, PC10, MKN-1, MKN-28, KB, Daudi, H-7 and ZR-75-1). Thus, the combined treatment with nHuTNF-alpha and nHuIFN-alpha or -gamma expanded the spectrum of sensitive cells. These results indicate that the combined use of nHuTNF and nHuIFN may provide a certain approach to cancer treatment.