[A basic study of cytotoxic effect of tumor necrosis factor-alpha on the hepatoma cell line, PLC/PRF/5]

In order to investigate the effect of tumor necrosis factor (recombinant TNF-alpha) on hepatoma, we assessed the antitumor activity of TNF-alpha on hepatoma cell line, PLC/PRF/5 in vitro, and combined effects of interferon-gamma (IFN-gamma), that is thought to increase TNF-receptors. TNF-receptors. TNF-alpha for itself, had no significant effect on DNA synthesis and viability, and the production of HBsAg from PLC/PRF/5. On the other hand, treatment of IFN-gamma- combined with TNF-alpha inhibited DNA synthesis and production of HBsAg. The decrease of viability of PLC/PRF/5 was also found in this combination treatment. According to these findings, antitumor activity of TNF-alpha had no effect on PLC/PRF/5 in itself, but was significantly enhanced when treated with IFN-gamma at the same time.