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

Abstract

Background: Circular RNAs (circRNAs) represent a class of broad and diversified endogenous RNAs that regulate gene expressions in eukaryotes. Hsa_circ_006675 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 hsa_circ_0066755 in NPC. Methods: We detected the expression levels of hsa_circ_0066755 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 hsa_circ_0066755 . Luciferase reporter assays were finally carried out to verify the binding sites. Results: We found significant increases of hsa_circ_0066755 in the plasma and tissues of the patients. Moreover, its levels were positively correlated with clinical staging ( P =0.019). The receiver operating characteristic (ROC) analysis showed that the area under the curves (AUCs) of tissue and plasma hsa_circ_0066755 for distinguishing NPC from non-cancerous controls were 0.8537 and 0.9044, respectively. Both tissue and plasma hsa_circ_0066755 testing presented a comparable diagnostic accuracy to the magnetic resonance imaging (MRI). Our in-vitro experiment showed that the overexpression of hsa_circ_0066755 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 hsa_circ_0066755 could significantly enhance the in-vivo tumorigenic ability of CNE-1 cells. Rescue assay further confirmed hsa_circ_0066755 as a tumor facilitator by sponging miR-651 . Conclusions: Collectively, this study reported for the first time that hsa_circ_0066755 played a role of oncogene in NPC and could be used as an effective diagnostic marker for NPC, and that hsa_circ_0066755 / miR-651 axis also involved in the progression of NPC.

Downregulation of circ_0000673 Promotes Cell Proliferation and Migration in Endometriosis via the Mir-616-3p/PTEN Axis

“…The proliferation and migration of endometrial tissue outside of the uterus is a defining characteristic of endometriosis, although the details of the pathological progression remain largely unknown 23 . CircRNAs have been recognized as important molecules in various biological processes, and abnormalities in their abundance or function may contribute to many diseases 3 , 24 , 25 . Studies have shown the abnormal expression of circRNAs in endometriosis and indicated their value in the diagnosis of diseases 26 , 27 .…”

Diagnostic and Prognostic Value of Circulating CircRNAs in Cancer

“…The AUC (area under the curve) value for differentiating radioresistant patients from radiosensitive patients was 0.945, with a sensitivity of 90.24% and a specificity of 94.51% ( 45 ). Wang et al ( 46 ) observed a significant increase of hsa_circ_0066755 in the NPC patients' plasma with an AUC value of 0.904. Meanwhile, plasma hsa_circ_0066755 testing presented a comparable diagnostic accuracy to the magnetic resonance imaging (MRI) ( 46 ).…”

“…Wang et al ( 46 ) observed a significant increase of hsa_circ_0066755 in the NPC patients' plasma with an AUC value of 0.904. Meanwhile, plasma hsa_circ_0066755 testing presented a comparable diagnostic accuracy to the magnetic resonance imaging (MRI) ( 46 ). Thus, circRNA_000285 and circMYC represent diagnostic and prognostic value for NPC, while hsa_circ_0066755 exhibits merely diagnostic characteristic.…”

Research Progress of circRNAs in Head and Neck Cancers

“…Multiple circRNAs have been demonstrated to be involved in HNC development through the regulation of the proliferation process ( Figure 1 ). CircATRNL1 ( 40 ), hsa_circ_0007059 ( 41 ), circRNA_002178 ( 42 ), hsa_circ_0046263 ( 43 ), hsa_circ_0005379 ( 44 ), circUHRF1 ( 45 ), circPVT1 ( 46 , 47 ), circHIPK3 ( 48 , 49 ), circRNA_0000140 ( 50 ), circRNA_100290 ( 51 ), circDOCK1 ( 52 ), hsa_circ_0055538 ( 53 ), circITCH ( 54 ), hsa_circRNA_101036 ( 55 ), circCCND1 ( 20 ), circMYLK ( 56 ), CDR1as ( 17 , 57 , 58 ), circPKD2 ( 59 ), circLARP4 ( 60 ), hsa_circ_0042666 ( 61 ), hsa_circRNA_100533 ( 62 ), circMDM2 ( 63 ), circ_0067934 ( 64 ), circRPMS1 ( 65 ), circ-ZNF609 ( 66 , 67 ), hsa_circ_0072387 ( 68 ), circRASSF2 ( 38 ), hsa_circ_0023028 ( 69 ), circCTDP1 ( 70 ), circ_0008450 ( 71 ), circMATR3 ( 72 ), hsa_circ_0057481 ( 73 ), circ_0001742 ( 74 ), circ_0000218 ( 75 ), circ_0001971 ( 76 ), circCORO1C ( 77 ), hsa_circ_0109291 ( 78 ), hsa_circ_0036722 ( 34 ), hsa_circ_0002203 ( 79 ) and hsa_circ_0066755 ( 80 ) are associated with tumor proliferation ( Table 1 ).…”

“…CircRNAs in HNC have important roles in HNC metastasis and invasion ( Figure 2 ). Hsa_circ_0007059 ( 41 ), circUHRF1 ( 45 ), circHIPK3 ( 48 ), circRNA_0000140 ( 50 ), circRNA_100290 ( 51 ), hsa_circ_0055538 ( 53 ), CDR1as ( 17 , 57 ), circPKD2 ( 59 ), circLARP4 ( 60 ), hsa_circ_0042666 ( 61 ), hsa_circRNA_100533 ( 62 ), circ_0067934 ( 64 ), circRPMS1 ( 65 ), circ-ZNF609 ( 66 ), hsa_circ_0072387 ( 68 ), circRASSF2 ( 38 ), hsa_circ_0023028 ( 69 ), circCTDP1 ( 70 ), circ_0008450 ( 71 ), circMATR3 ( 72 ), hsa_circ_0057481 ( 73 ), circ_0001742 ( 74 ), circCORO1C ( 77 ), hsa_circ_0004491 ( 37 ), circ_0001971 ( 33 ), circFLNA ( 99 ), hsa_circ_0001162 ( 100 ), circARHGAP12 ( 101 ), circCRIM1 ( 102 ), circEPSTI1 ( 103 ), hsa_circ_0109291 ( 78 ), circRNA_002178 ( 42 ), hsa_circ_0002203 ( 79 ) and hsa_circ_0066755 ( 80 ) are involved in the regulation of HNC invasion and metastasis ( Table 2 ).…”