Introduction : Gallbladder carcinoma (GBC), the most common malignant tumour of the bile duct, is highly aggressive and has a poor prognosis. MicroRNA-30a-5p (miR-30a-5p) is an important tumour suppressor that participates in many aspects of carcinogenesis and cancer development. However, the role of miR-30a-5p in GBC development remains to be determined, as do the mechanisms underlying its effects in GBC.

Methods : In vitro and in vivo studies revealed that miR-30a-5p inhibited GBC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro and in vivo.

Results : In this study, we identified miR-30a-5p as a tumour suppressor and its expression levels were significantly downregulated in GBC and were closely associated with overall survival (OS) and disease-free survival (DFS) in 42 patients with GBC. E2F transcription factor 7 (E2F7) was a direct target of miR-30a-5p and antagonized the effects induced by miR-30a-5pdown-regulation in GBC cells.

Conclusions : MiR-30a-5p attenuates the EMT and metastasis in GBC cells by targeting E2F7, suggesting miR-30a-5p is a tumour suppressor that may serve as a novel potential prognostic biomarker or molecular therapeutic target for GBC.