MiR-381-3p inhibits proliferation, migration and invasion by targeting LRP6 in papillary thyroid carcinoma

OBJECTIVE: MiR-381-3p plays an essential role in the progression of a variety of cancers, but its expression and role in papillary thyroid carcinoma (PTC) progression have not been investigated. The aim of this study was to investigate the expression of miR-381-3p and its function in PTC. PATIENTS AND METHODS: The expression levels of miR-381-3p and low-density lipoprotein receptor-related protein 6 (LRP6) mRNA in PTC tissues and cell lines were measured using RT-PCR. Cell proliferation, migration and invasion were assessed by cell viability assay and transwell assay. Luciferase assays and Western blotting were performed to demonstrate miR-381-3p target gene. RESULTS: We found that miR-381-3p was significantly down-regulated in PTC tissues and cell lines. In vitro assay indicated that up-regulation of miR-381-3p significantly suppressed PTC cell proliferation, migration and invasion. Moreover, luciferase reporter gene assay demonstrated that miR-381-3p could target LRP6 by binding to the 3' UTR. Western blot and Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) showed that miR-381-3p overexpression suppressed the expression of LRP6 at both mRNA and proteins levels. In addition, functional experiment confirmed that LRP6 was involved in the suppressive effect of miR-381-3p-mediated PTC on cell proliferation, migration and invasion. CONCLUSIONS: Our findings suggested, for the first time, that miR-381-3p was lowly expressed in PTC tissues, and its up-regulation inhibited tumorigenesis of PTC by targeting LRP6.