TNF? Induces Tolerant Production Of CXC Chemokines In Colorectal Cancer HCT116 Cells Via A20 Inhibition Of ERK Signaling

Objective:To investigate the mechanism of CXC chemokine production tolerance induced by TNF? pretreatment.Methods:The colorectal cancer HCT116 cells were cultured for expansion invitro.A model of CXC chemokine production tolerance in colorectal cancer HCT116 cells induced by TNF? pretreatment was established.The secretion of CXC chemokines in the supernatant and the expression of CXC chemokine m RNA in HCT116 cells were analyzed by ELISA and q RT-PCR.The effect of TNF?to the expression of TNFR1 and TNFR2 in HCT116 cells was detected by RT-PCR and FACS.The connection between the activation of MAPKs and NF?B pathway and the production of CXC chemokines were detected by q RT-PCR and Western blot analysis.The effect of TNF? on the expression of A20 was detected by q RT-PCR and Western blot.HCT116 cells were transfected with A20 overexpression plasmid and the effect of A20 overexpression on TNF?-induced chemokine production.After si RNA inhibits A20 expression in HCT116 cells,TNF? pretreatment induces chemokine production tolerance by q RT-PCR.Results:1.TNF ? pretreatment induced tolerance to CXC chemokine production in HCT116 cells.2.The expression of TNF receptor in HCT116 cells is not regulated by TNF?.3.TNF? induced CXC chemokine production in HCT116 cells through ERK signaling pathway.4.TNF? upregulated the expression of A20 in HCT116 cells.5.Overexpression of A20 inhibited TNF?-induced HCT16 cell chemokine production and ERK activation.6.Inhibition of A20 reversed down-regulation of CXC chemokines induced by TNFa reconditioning as indicated by TNFa pretreatment.Conclusion:1.In human colorectal cancer HCT116 cells,TNF ? induced a tolerant production of CXC chemokines.2.A20 may reverse TNF ? pretreatment-induced chemokine production tolerance by inhibiting ERK signaling pathway.