Inhibits Tumor Growth and Metastasis in Papillary Thyroid Carcinoma Cell Lines by Targeting and .

Background: MicroRNA (miRNA) dysregulation was commonly seen in papillary thyroid carcinoma (PTC), and was verified to be downregulated in PTC by the large data set analysis from The Cancer Genome Atlas (TCGA). Our study aimed to explore the biological functions and the underlying molecular mechanisms of in PTC.

Methods: The relative expression of and its target genes were assessed by quantitative RT-PCR assay in 38 pairs of PTC and the adjacent thyroid tissues. Assays were performed to evaluate the effect of on the proliferation, migration, and invasion in PTC cell lines. Moreover, we searched for targets of and explored the possible molecular pathway of in PTC.

Results: We found that was downregulated in PTC cell lines and tissues. Overexpression of significantly inhibited cell proliferation, migration, and invasion in K1 and BCPAP cell lines. and , which had inverse correlations with in clinical specimens, were found to be the direct targets of . Furthermore, might be involved in PTC tumorigenesis by suppressing the Wnt/-catenin signaling pathway.

Conclusions: These results highlight an important role of in the initiation and progression of PTC and implicate the potential application of in PTC target therapy.