Circ_100395 impedes malignancy and glycolysis in papillary thyroid cancer: Involvement of PI3K/AKT/mTOR signaling pathway.

Circular RNAs (circRNAs) play critical roles in cancer procession, including papillary thyroid cancer (PTC). Despite of published reports regarding the abnormal downregulation of circ_100395 in PTC, the role and regulatory mechanism of which are still undiscovered. Circ_100395 expression was examined via qRT-PCR. Cell growth was detected by the CCK-8 and colony formation, BrdU incorporation and flow cytometry assays. Cell migration and invasion were measured using transwell assays. Aerobic glycolysis was analyzed by the glucose uptake and lactate production. Immunoblotting was performed to evaluate the associated proteins. Decreased circ_100395 expression was shown in PTC tissues and cell lines. Circ_100395 overexpression significantly reduced aerobic glycolysis and the survival, migration and invasion abilities and downregulated phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway, which were reversed by the PI3K activator 740Y-P. Our data demonstrated that circ_100395 may play an anti-oncogenic role in PTC cells through the inhibition of PI3K/AKT/mTOR signaling pathway.