miR-188-5p inhibits proliferation, migration, and invasion in gallbladder carcinoma by targeting Wnt2b and Smad2.

Gallbladder carcinoma (GBC) commonly occurs in gastrointestinal malignancy and has the fifth highest mortality rate among gastrointestinal malignancy. Recently, miR-188-5p, a small noncoding RNA, has been implicated in various types of cancer such as nasopharyngeal carcinoma, oral squamous cell carcinoma, liver cancer, and prostate cancer. However, the effect of miR-188-5p on GBC remains unclear. Here, we demonstrated that miR-188-5p was downregulated in GBC tissues, and downregulation of miR-188-5p correlated with larger tumor size, lymph node metastasis, and extensive metastasis. In addition, the overall survival time of patients with higher miR-188-5p expression was significantly longer than that of patients with low-miR-188-5p expression. Moreover, downregulation of miR-188-5p promoted the proliferation, migration, and invasion of GBC cells, while its overexpression inhibited cell invasion and induced cell apoptosis, and arrested GBC growth in vivo. Importantly, miR-188-5p-dependent tumorigenesis was correlated with Wnt/β-catenin signaling and p-38/JNK signaling. In conclusion, miR-188-5p plays a direct role in GBC tumorigenesis. Our study suggests that miR-188-5p could serve as a novel diagnosis marker and therapeutic target in GBC.