MicroRNA-137 suppresses the proliferation, migration and invasion of cholangiocarcinoma cells by targeting WNT2B

It is widely known that abnormal regulation of microRNAs (miRNAs/miRs) may contribute to the occurrence or development of tumors. The objective of the present study was to elucidate the function and underlying mechanism of miR-137 in the progression of cholangiocarcinoma (CCA). The expression levels of miR-137 in CCA tissues and cell lines were measured using reverse transcription-quantitative PCR. The role of miR-137 in the proliferation of CCA cells was assessed using the Cell Counting Kit-8 assay, colony formation assay and cell cycle distribution analysis, while its effects on the migration and invasion of CCA cells were evaluated using Transwell assays. The function of miR-137 on CCA growth in vivo was also investigated using a xenograft mouse model. Furthermore, the association between miR-137 and Wnt family member 2B (WNT2B) was analyzed using bioinformatics, double luciferase assay and western blotting. It was verified that the expression of miR-137 was low in CCA tissues and cell lines, whereas increased expression of miR-137 significantly suppressed cell proliferation, decreased colony formation ability and induced G1 phase arrest. miR-137 overexpression suppressed the migration and invasion ability of TFK-1 and HuCCT1 cells. Furthermore, the results of the xenograft mouse model assays revealed that miR-137 overexpression decreased tumor growth in vivo. The results of bioinformatics analysis and dual luciferase reporter assays demonstrated that WNT2B is directly regulated by miR-137. The expression of WNT2B and Wnt-pathway-related proteins was decreased when miR-137 was overexpressed. Restoring the expression of WNT2B notably reversed the inhibitory effect of miR-137 on CCA cells. Therefore, the findings of the present study demonstrated that miR-137 acts as a suppressor in CCA and inhibits CCA cell proliferation, migration and invasion through suppressing the expression of WNT2B.