MiR-509-5p improves the proliferative and invasive abilities of papillary thyroid carcinoma cells by inhibiting SFRP1

Introduction: Our study was conducted to prove that miR-509-5p improved the proliferative and invasive abilities of papillary thyroid carcinoma (PTC) cells through inhibiting SFRP1 expression. Material and methods: QRT-PCR was conducted in order to detect the miR-509-5p expression levels in PTC and normal tissues. The miR-509-5p and SFRP1 mRNA expression levels in PTC cell lines K1, TPC-1, BCPAP and the human normal thyroid cell line HT-ori3 were also detected by qRT-PCR. The transfection was performed using Lipofectamine and lentiviral vectors. Pgc-sil-008 was used as the SFRP1 gene vector. Western blot and dual luciferase reporter gene assay were conducted to investigate miR-509-5p's direct regulation on SFRP1. MTT, clone formation, and Transwell assays were adopted to investigate the biological behaviors of PTC cells. TCF/LEF luciferase assays were used to prove that miR-509-5p influenced the Wnt/beta-catenin signaling pathway by regulating SFRP1. Results: MiR-509-5p was overexpressed in PTC cells and tissues in which SFRP1 was down-regulated. MiR-509-5p bound to the 3'-UTR of SFRP1 and therefore partially weakened the proliferative, migrating and invasive activities of PTC cells. MiR-509-5p promoted activation of the Wnt/beta-catenin signaling pathway through down-regulating SFRP1. Conclusions: MiR-509-5p improved the proliferative, migrating and invasive abilities of PTC cells through inhibiting SFRP1 expression.