miR-199a-5p inhibits the progression of papillary thyroid carcinoma by targeting SNAI1

Highlights: • miR-199a-5p expression is downregulated in PTC tissues and cells. • miR-199a-5p overexpression suppressed the progression of PTC cells. • SNAI1 is a target of miR-199a-5p and miR-199a-5p suppressed SNAI1 expression in PTC cells. • SNAI1 knockdown inhibited the progression of PTC cells. • miR-199a-5p overexpression hindered tumor growth in PTC in vivo. Increasing evidence has emphasized the important roles of differentially expressed miRNAs in papillary thyroid cancer (PTC) development. miR-199a-5p was previously documented to be downregulated in PTCs compared with normal thyroids. However, the role of miR-199a-5p in the progression of PTC and the underlying mechanism remain to be further addressed.