Recombinant human tumor necrosis factor--I. Cytotoxic activity in vitro.

Cytotoxic activity of recombinant human TNF (rHu-TNF) on various human cell lines was examined in vitro. rHu-TNF exerted a cytostatic effect on various types of human tumor cells such as carcinoma, sarcoma, leukemia, melanoma and other types. When the cytocidal effect was examined on the tumor cells which were cytostatically susceptible to rHu-TNF, the cytocidal effect of rHu-TNF was also noticed on many of these tumor cells. However, some tumor cells were affected cytostatically only. Human diploid cells were not affected cytostatically or cytocidally by rHu-TNF. WI-38 VA13 cells which are an SV-40-transformed derivative of WI-38 diploid cells, were affected both cytostatically and cytocidally by rHu-TNF. These results suggest that rHu-TNF exerts cytostatic and cytocidal effects against a broad spectrum of human tumor cells, and its cytotoxic activity is tumor-specific.