MicroRNA-146b-5p inhibits the growth of gallbladder carcinoma by targeting epidermal growth factor receptor

Gallbladder cancer (GBC) is the most common and aggressive type of biliary tract cancer. The study of potential treatments for GBC has recently focused on microRNAs, a class of small non-coding RNAs, which post-transcriptionally regulate gene expression during various crucial cell processes. The present study aimed to investigate the role of microRNA-146b (miR-146b) in GBC. Human GBC tissue and adjacent normal gallbladder tissue sections were surgically removed and miR-146b-5p expression and the development and pathological characteristics of GBC were investigated. miR-146b-5p expression was reduced in GBC tissue compared with that in adjacent tissue, and a significant correlation was observed between miR-146b-5p expression levels and carcinoma size and development. miR-146b-5p overexpression in the SGC-996 GBC cell line inhibited cell growth through enhanced apoptosis and G(1) phase arrest. Furthermore, it was demonstrated that epidermal growth factor receptor (EGFR) was regulated directly by miR-146b-5p and was essential as a mediator of the biological effects of miR-146b-5p in GBC. Enforced expression of EGFR reversed the ability of miR-146b-5p to inhibit proliferation. In conclusion, the present study indicated that the mechanism of action of miR-146b-5p in GBC involves the regulation of EGFR expression.