Abstract: Objective To explore the expression of the RNA-binding protein tristetraprolin in lung adenocarcinoma cells and its molecular mechanism for inhibiting autophagy. Methods Quantitative real-time PCR and Western blotting were performed to detect the expression of autophagy-related genes (including Beclin1, LC3-II/LC3-I and SQSTM1/p62) in cultured lung adenocarcinoma cells at 24, 48 and 72 h after transient transfection with a tristetraprolin-overexpressing plasmid and the empty plasmid. The effects of transfection with the tristetraprolin-overexpressing plasmid and empty plasmids in the presence or absence of tumor necrosis factor-α (TNF-α) on the expressions of nuclear factor-κB (NF-κB) p65, c-rel, and p50 were examined in lung adenocarcinoma cells using immunofluorescence assay and Western blotting. The cells were also transfected with the IκBα-mut plasmid and the tristetraprolin-overexpressing plasmid, either alone or in combination, and the changes in the expressions of tristetraprolin and autophagy-related genes were detected using RT-qPCR and Western blotting. Results The expressions of tristetraprolin were significantly reduced at both the mRNA and protein levels in lung adenocarcinoma cells (P<0.001). Overexpression of tristetraprolin in the cells significantly lowered the expressions of autophagy-related genes Beclin1 and the ratio of LC3-II/LC3-I at the mRNA and protein levels (P<0.001), obviously lowered the expressions of NF-κB p65 and c- rel, and almost totally blocked the nuclear translocation of NF-κB p65 and c-rel (P<0.05); the expression of p50, however, did not undergo significant changes in response to tristetraprolin overexpression (P>0.05). The inhibitory effect of tristetraprolin overexpression on autophagy was abrogated by transfection of the cells with IκBα-mut plasmid, which blocked the NF-κB signaling pathway. Co-transfection of the cells with IκBα-mut also attenuated the inhibitory effect of tristetraprolin overexpression on Beclin1 and the LC3- II/LC3- I ratio at both the mRNA and protein levels (P<0.05). Conclusion The expression of tristetraprolin is low in lung adenocarcinoma cells. Tristetraprolin overexpression causes inhibition of autophagy in lung adenocarcinoma cells possibly by blocking NF-κB p65 and c-rel nuclear translocation.