Tumoricidal function against human cervical-cancer cells in human peritoneal mesothelial cells - contribution of tumor-necrosis-factor-alpha.

The present study demonstrates the important and novel finding that human mesothelial cells possess tumoricidal activity. This cytotoxicity in mesothelial cells was induced by recombinant human interferon (rhIFN)-gamma and was measured against the human cervical carcinoma cell line, ME-180, by Cr-51-release, visual assessment and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide uptake assays. Tumor necrosis factor (TNF)-alpha-sensitive ME-180 cells were shown to be lysed by 24-h-rhIFN-gamma-treated-mesothelial cell-supernatants alone, which was partially inhibitable by anti-TNF-alpha. Induction of TNF-alpha in mesothelial cells was confirmed by Northern blotting. Our data describe a novel rhIFN-gamma-activated cytotoxic function in mesothelial cells, and suggest the involvement of TNF-alpha as one of the lytic mechanisms. These results are of extreme importance in relation to the future understanding of general local carcinogenic processes, and henceforth therapies.