miR-146b-5p inhibits tumorigenesis and metastasis of gallbladder cancer by targeting Toll-like receptor 4 via the nuclear factor-κB pathway

Gallbladder cancer (GBC) is a carcinoma of the biliary tract, which is common in developing countries and is associated with a high fatality rate. The aim of the present study was to investigate the mechanisms underlying the occurrence and development of GBC. A decrease in the expression of miR-146b-5p and an increase in the expression of its target gene Toll-like receptor 4 (TLR4) were first observed in GBC tissues. Further study demonstrated that an increase in TLR4 expression caused by a decrease in miR-146b-5p expression led to activation of nuclear factor (NF)-κB signaling. GBC cells were cultured in vitro, and it was observed that overexpression of miR-146b-5p effectively inhibited their viability, proliferation, migration and invasion, and increased their apoptosis. Using a BALB/c nude mouse xenograft model, it was demonstrated that overexpression of miR-146b-5p was sufficient to reduce tumor volume and alleviate pathological characteristics. Overall, the results of the present study indicated that the decrease in the expression of miR-146b-5p increased TLR4 expression and indirectly activated the NF-κB signaling pathway, thereby regulating the development of GBC.