Has_circ_0008274 promotes cell proliferation and invasion involving AMPK/mTOR signaling pathway in papillary thyroid carcinoma

OBJECTIVE: Circular RNAs (circRNAs) have been known as important regulators in tumorigenesis. Whether circRNAs are involved in papillary thyroid carcinoma (PTC) requires to be determined. In the present study, we aimed to investigate the expression and function of has_circ_0008274 in PTC. PATIENTS AND METHODS: Tissue expression of has circ 0008274 was evaluated in Gene Expression Omnibus datasets (GSE93522). Real-time PCR assays were used to detect the expression of has_circ_0008274 in human PTC tissues and cell lines. The correlation of has_circ_0008274 expression with clinicopathological factors was statistically analyzed. The MTT assay, colony formation assay, transwell assays were performed to analyze and compare cell viability and invasion. Western blot analysis was used to quantify the expression of AMPK/mTOR signaling pathway proteins. RESULTS: We found that has_circ_0008274 was significantly upregulated in PTC tissues, and the level of has_circ_0008274 was negatively associated with TNM stage and lymph node metastasis. Loss-of-function assay indicated that knockdown of has_circ_0008274 suppressed PTC cells proliferation and invasion in vitro. Mechanistically, has_circ_0008274 could inhibit the activation of AMPK/mTOR signaling pathway, which was demonstrated by measuring the expression levels of p-AMPK and p-mTOR. CONCLUSIONS: These results demonstrate that increased has_circ_0008274 expression modulates has_circ_0008274 to enhance PTC cells proliferation and invasion. Has_circ_0008274/ AMPK/mTOR axis may be a novel therapeutic candidate target in PTC treatment.