Unveiling hsa_circ_0007439: a novel suppressor of nasopharyngeal carcinoma via miR-556-5p/PTEN Axis

There has been no explanation for the exact mechanism of circRNAs in nasopharyngeal carcinoma (NPC). Circ_0007439 was investigated in this study to determine its role and mechanism in NPC.

To identify circ_0007439, microRNA (miR)-556-5p, and PTEN mRNA in NPC tissues and cells, RT-qPCR was employed. PTEN protein was quantified using western blot analysis. The impact of circ_0007439 on cellular activities was assessed using CCK-8, colony formation, Transwell, and flow cytometry, in that order. The interaction of miR-556-5p with circ_0007439 or PTEN mRNA was confirmed through a dual luciferase reporter gene assay and RIP assay.

circ_0007439 and PTEN levels were low in NPC tissues and cells, while miR-556-5p was highly expressed. NPC cells were inhibited in proliferation, migration, invasion, and anti-apoptosis when circ_0007439 was upregulated or miR-556-5p was reduced. The circ_0007439 molecule acted as a molecular sponge that inhibited miR-556-5p’s suppression of PTEN expression. Additionally, reduction of PTEN weakened the inhibitive effects of elevating circ_0007439 or reducing miR-556-5p on NPC cells.

Circ_0007439 mediates miR-556-5p/PTEN axis to inhibit NPC progression as an potential target for NPC therapy.