MicroRNA-1225-5p inhibits the development and progression of thyroid cancer via targeting sirtuin 3.

The objective of this study was to grab the expression levels and biological function of microRNA-1225-5p in human thyroid cancer. The miR-1225-5p expression in thyroid cancer tissue and cell lines was detected, followed by detecting the effects of overexpression of miR-1225-5p on the proliferation, apoptosis, migration and invasion of thyroid cancer cells. Moreover, the target relationship between miR-1225-5p and sirtuin 3 (SIRT3) was investigated. Besides, the effect of miR-1225-5p on the activation of Wnt/β-catenin pathway was elucidated. The miR-1225-5p expression was downregulated in thyroid cancer tissues and cell lines. Overexpression of miR-1225-5p significantly inhibited TPC-1 cell proliferation, increased cell apoptosis, and suppressed migration and invasion. In addition, SIRT3 was verified as a functional target of miR-1225-5p. SIRT3 expression was overtly increased in thyroid cancer tissues and cell lines. Overexpression miR-1225-5p and SIRT3 at the same time could significantly reverse the effects of miR-1225-5p overexpression alone on the malignant phenotypes of thyroid cancer cells. Furthermore, overexpression of miR-1225-5p significantly inhibited the activation of the Wnt/β-catenin pathway, which was remarkably reversed after overexpression of SIRT3. Our data reveal that downregulation of miR-1225-5p may promote tumor cell proliferation and metastasis in thyroid cancer via a direct targeting of SIRT3. Activation of the Wnt/β-catenin pathway may be a key mechanism to mediate the role of miR-1225-5p/SIRT3 axis in thyroid cancer. miR-1225-5p may serve as a potential anti-cancer target for thyroid cancer treatment.