In vitro antitumor effect of recombinant human tumor necrotizing factor on cultured human cancer cell lines and freshly isolated lung cancer cells by the human tumor clonogenic assay.

In vitro antitumor effects of human recombinant tumor necrotizing factor (rH-TNF) were examined against nine lung cancer cell lines including six non small and three small cell lung cancer, four stomach cancer cell lines and 30 freshly isolated lung cancer cell samples by the human tumor clonogenic assay. rH-TNF did not show any inhibitory effect on the colony formations of lung and stomach cancer cell lines, except for PC10 established from squamous cell carcinoma even at the high concentration. The overall response rate of fresh material was 11.5%. The colony formations of only two materials from 20 patients without prior chemotherapy were significantly suppressed by rH-TNF in vitro. Three specimens of adenocarcinoma exhibited more than 70% decrease in colony number by treating with 100 and 1000 u/ml of rH-TNF resulting in the response rate of 15.8% (3/19). From these results, it can be concluded that rH-TNF has modest direct cytotoxic effect on lung cancer, and additional study against adenocarcinoma of the lung might be warranted.