Abstract
Circular RNAs (circRNAs) have been shown to regulate the development and progression of various cancers. However, the expression and function of circRNAs in papillary thyroid cancer (PTC) remain largely unknown. This study is aimed to investigate the potential roles of circEIF3I in PTC and elucidate the functional mechanism. We found that the expression of circEIF3I was significantly upregulated in PTC tissues compared to adjacent normal tissues. CircEIF3I expression was positively associated with tumor size, TNM stage and metastasis. CircEIF3I knockdown remarkably suppressed the proliferation, migration and invasion of PTC cells. Mechanistically, circEIF3I promoted KIF2A expression through competitively interacting with miR-149. In conclusion, circEIF3I upregulation in PTC tissues facilitates KIF2A expression by inhibiting miR-149, leading to malignant progression of PTC. This study suggested circEIF3I/miR-149/KIF2A axis might be a potential therapeutic target.