MiR-200c promotes proliferation of papillary thyroid cancer cells via Wnt/β-catenin signaling pathway.

OBJECTIVE To investigate the potential effects of miR-200c on proliferation and apoptosis of papillary thyroid cancer (PTC) cells. MATERIALS AND METHODS Micro ribonucleic acid-200c (miR-200c) inhibitor was transfected to down-regulate miR-200c expression. Cell counting kit-8 (CCK-8), colony formation experiment, and flow cytometry were used to detect the effects of miR-200c knockdown on proliferation and apoptosis of Butylated Hydroxytoluene 101 (BHT101) cells. The dual-luciferase reporter gene assay was conducted to detect whether miR-200c directly binds to the target gene. After knocking down miR-200c, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting analysis were performed to detect changes of target genes regarding messenger RNA (mRNA) and protein. Western blotting analysis was also adopted to detect gene expression of Wnt/β-catenin signaling pathway-related proteins. RESULTS Compared with those in control group, the proliferation and clone formation ability of BHT101 cells in miR-200c knockdown group were significantly inhibited (p<0.05), while the apoptosis rate increased markedly (p<0.05). Dachshund Family Transcription Factor 1 (DACH1) was the direct target gene of miR-200c. After miR-200c knockdown, the expression levels of Wnt/β-catenin signaling pathway members (including c-Myc, β catenin and cyclin D1) all decreased. CONCLUSIONS MiR-200c is a tumor suppressor miRNA, which promotes proliferation of PTC cells and activates Wnt/β-catenin signaling pathway by directly regulating the corresponding target protein, DACH1.