Expression Of TNFRs In Tumor Cells And Effect Of NrhTNF On Tumor Cells Growth And NF-kB Activity

Objective TNF-a, a cytokine with wild-ranging bioactivity, is produced by macrophage and activated T cell. Human TNF-a transfers its biology responses through two distinct receptors: TNFRpSS of which MW is 55-60KD, and TNFRp75 of which MW is 75-80KD. Because of the character of hemorrhage necrosis, people have started research and development of recombination human TNF(rhTNF) as clinical anti-tumor drugs since 1980's. Nowadays, the novel recombination human TNF(nrhTNF) constructed by this biotechnology center of this university has come into III stage clinical trial. Many clinical reports show that although the anti-tumor effect of rhTNF is quite certain, the curative effect is still erratic and the side effect is rather serious. All of these limited the application in clinical use. People have made efforts in many researches in order to enhance the cure effect and deduce the side effect. Among the researches, the activation of NF-KB pathway is continuously a focus. Being activated, NF-KB can inhibit cell apoptosis, maintain cell stable and assist the anti-tumor effect of TNF. We investigated the relationship between the TNFRpSS and TNFRp75 expression on tumor cells and the inhibition of nrhTNF to tumor cells. And then, we detected the effect of nrhTNF on tumor cells growth and the changing of NF-KB activity.Methods The expression and distribution of TNFRs in 10 rumor cell lines and 120 cases of tumor tissues are investigate by using immunohistochemistry. The inhibition of nrhTNF to tumor cells was investigated by crystal violet assay. The changing of activation of NF-KB is evaluated by using immunohistochemistry and western blot.Results In the tumor tissues and tumor cell lines, positive rates of TNFRp55 were 82.5% and 99% respectively, while that of TNFRp75 were 84.2% and 98.8% respectively. There were no significant differences among various types tumor(/7>0.05). nrhTNF induced apoptosis in SW480, SGC7901, 8910, SMMC7721 and BEL7402 cell lines in which NF-KB translocated into cytonuclear slightly. However, nrhTNF had no effect on A549, PLA801, Hela, Ecal09 and GRC-1 cell lines in which NF-KB translocated into cytonuclear obviously. Conclusions TNFRs exist wildly on various kinds of tumor cells. There is no correlation between nrhTNF inhibition on tumor cell lines growth and TNFRp55 expression on these tumor cells. The lower degree activation of NF-KB makes tumor cells sensitive to nrhTNF, however, the higher degree of activation of NF-KB makes tumor cells insensitive to nrhTNF.