Effect of TLR4/NF-κB signaling pathway on extracellular release of HMGB1 in lipopolysaccharide-induced laryngeal Hep-2 carcinoma cells

Objective To investigate the lipopolysaccharide(LPS)-induced extracellular release of high mobility group box 1(HMGB1)in laryngeal Hep-2carcinoma cells.Methods The changes of HMGB1concentration in the culture medium and the expressions of HMGB1mRNA,Toll-like receptor 4(TLR4)and nuclear factor-kappaB(NF-κB)were detected by ELISA,RT-PCR and Western blot,respectively,after Hep-2cells were stimulated with LPS for 12hand 18h.Inhibitory effect of antiTLR4monoclonal antibody and PDTC was observed on HMGB1release.Results The level of HMGB1mRNA expression and the HMGB1concentration significantly increased in a time-dependent manner after Hep-2cells were induced by LPS for 12hand 18h,respectively.The expressions of TLR4and NF-κB p65protein were significantly upregulated after induced by LPS for 24h.AntiTLR4monoclonal antibody and PDTC partly inhibited extracellular release of HMGB1in LPS-induced Hep-2cells.Conclusion LPS induces laryngeal carcinoma cells to release HMGB1,which may be related to TLR4/NF-κB signaling pathway.