抄録
Tumor necrosis factor (TNF) has attracted much attention because of its unique biological characteristics such as oncolytic capabilities, a lack of species specificity, and the ability to discriminate between normal and certain tumor cells in vitro. This study was made to determine in vitro induction of endogenous TNF and its cytotoxicity against renal cell carcinoma cells, KU2 and Caki 1. Endogenous TNF titers were assayed by cytotoxicity against L929 using anti-TNF antibodies. Endogenous TNF induced by in vitro culture of PBL with OK432 showed cytotoxicity against KU2 and Caki 1. The high level of TNF activity in the supernatant from PBL cultured with OK432 was noted at 12 hr of incubation and when the concentration of OK432 was adjusted to 0.05 KE/ml. Augmented production of TNF was observed at 48 and 72 hr of incubation when PBL were cultured with OK432 of 0.05 KE/ml and colony stimulating factor (CSF) of 100 units/ml. Based on the result that TNF can be produced by activated PBL with biological response modifiers (BRMs), TNF can be expected to play an integral role in complicated antitumor mechanisms brought about in a patient receiving BRMs. For the treatment of patients with advanced renal cell carcinoma, effective therapy through augmenting TNF activity should be taken into consideration.
