Long non-coding RNA TUG1 promotes cell proliferation and metastasis by negatively regulating miR-300 in gallbladder carcinoma.

BACKGROUND: As we all know, long non-coding RNAs (lncRNAs) have been reported to play vital roles in various human cancers. In this study, we aimed to explore the role of lncRNA TUG1 in gallbladder carcinoma (GBC) development.

METHODS: Total RNA was extracted from the tissues of thirty GBC patients, four GBC cell lines. We detected the expression levels of TUG1 using quantitative real-time PCR. We performed CCK8, colony formation, transwell invasion and apoptosis assays to study the effects of TUG1 on GBC cell proliferation and invasion. Western blot assay was performed to assess to the expression level of epithelial-mesenchymal transition (EMT) markers in transforming growth factor-β1 (TGF-β1) treated and TUG1 knockdown GBC cell. Lastly, dual-luciferase reporter assay and quantitative real-time PCR were performed to verify the potential target microRNAs (miRNAs) of TUG1.

RESULTS: TUG1 expression was significantly overexpressed in GBC tissues. Functionally, this study demonstrated that knockdown of TUG1 significantly inhibited GBC cell proliferation, metastasis. Mechanically, we found that TUG1 is upregulated by TGF-β1, and knockdown of TUG1 inhibited GBC cell EMT. Furthermore, we identified that miR-300, which has been reported as a suppressor in other types of cancer, is negatively regulated by TUG1.

CONCLUSIONS: LncRNA TUG1 promotes GBC cell proliferation, metastasis and EMT progression by functioning as a miRNA sponge to abrogate the endogenous effect of miR-300.