Circ_0049396 attenuates the progression of oral squamous cell carcinoma by miR-650 suppression to induce neurofilament heavy polypeptide enhancement

Objective. Circular RNAs regulate biological processes in various human tumors. We aimed to understand the regulatory function of circ_0049396 in the development of oral squamous cell carcinoma (OSCC). Study Design. We assessed miR-650, neurofilament heavy polypeptide (NEFH), and circ_0049396 expression levels in OSCC by quantitative reverse transcription polymerase chain reaction and validated their interactions using luciferase reporter and RNA-binding protein immunoprecipitation assays. We performed cell count kit-8, clone formation, and transwell migration assays to evaluate OSCC cell malignancy in vitro and established a mouse xenograft model to evaluate the tumor growth of OSCC cells in vivo. Results. Circ _0049396 and NEFH expression levels were reduced in OSCC, whereas miR-650 expression was elevated. Circ_0049396 upregulated NEFH expression by acting as a miR-650 sponge. Circ_0049396 overexpression inhibited the migra-tion and proliferation of OSCC cells and reduced tumor growth in vivo. The inhibitory effect of circ_0049396 overexpression on OSCC malignancy was attenuated by miR-650 enrichment. NEFH overexpression counteracted the promoting effect of miR-650 mimic transfection on OSCC progression. Conclusions. Circ_0049396 overexpression suppresses OSCC cell malignancy by suppressing miR-650 to regulate miR-650 target gene NEFH expression. Targeting this newly discovered mechanism for the circ_0049396/miR-650/NEFH axis in OSCC may be an effective treatment.