Circular RNA Hsa_circ_0066755 as an Oncogene via sponging miR-651 and as a Promising Diagnostic Biomarker for Nasopharyngeal Carcinoma.

Circular RNAs (circRNAs) represent a class of broad and diversified endogenous RNAs that regulate gene expressions in eukaryotes. has been proven as an important circRNA molecule in nasopharyngeal carcinoma (NPC), however, its function still remains elusive. This study aims to discuss the biofunctions of in NPC. We detected the expression levels of in NPC patients by quantitative real-time polymerase chain reaction (qRT-PCR), and the corresponding ROC curves were plotted. Functional experiments including CCK-8, colony formation, Transwell assay and Xenograft experiment were conducted. Bioinformatics analysis was performed to seek miRNAs which might have binding sites with . Luciferase reporter assays were finally carried out to verify the binding sites. We found significant increases of in the plasma and tissues of the patients. Moreover, its levels were positively correlated with clinical staging (=0.019). The receiver operating characteristic (ROC) analysis showed that the area under the curves (AUCs) of tissue and plasma for distinguishing NPC from non-cancerous controls were 0.8537 and 0.9044, respectively. Both tissue and plasma testing presented a comparable diagnostic accuracy to the magnetic resonance imaging (MRI). Our in-vitro experiment showed that the overexpression of facilitated the growth, proliferation, clone formation, invasion and migration of CNE-1 NPC cells, while its down-regulation showed completely opposite effects. The xenograft experiment showed that exogenous could significantly enhance the in-vivo tumorigenic ability of CNE-1 cells. Rescue assay further confirmed as a tumor facilitator by sponging . Collectively, this study reported for the first time that played a role of oncogene in NPC and could be used as an effective diagnostic marker for NPC, and that / axis also involved in the progression of NPC.