BACKGROUND: Circular RNA (circRNA) plays an important role in regulating cell 
biological function and has been shown to be involved in cancer progression, 
including oral squamous cell carcinoma (OSCC). Circ-KIAA0907 has been found to 
play an anti-cancer role in OSCC, so it is worth exploring more functions and 
new mechanisms of circ-KIAA0907 in OSCC progression.
METHODS: Quantitative real-time PCR (qRT-PCR) was used to detect the expression 
of circ-KIAA0907, microRNA (miR)-96-5p, and unc-13 homolog C (UNC13C). Transwell 
assay, flow cytometry, and colony formation assay were employed to measure the 
migration, invasion, apoptosis, and radiosensitivity of cells. Besides, glucose 
uptake, lactate production, and extracellular acidification rate (ECAR) were 
determined to evaluate the glycolysis ability of cells. Dual-luciferase reporter 
assay and RIP assay were performed to confirm the interactions among 
circ-KIAA0907, miR-96-5p, and UNC13C. And RNA pull-down assay was used to verify 
the binding degree of miR-96-5p to its targets. Moreover, UNC13C protein level 
was examined using western blot (WB) analysis. OSCC xenograft models were 
constructed to perform in vivo experiments.
RESULTS: Circ-KIAA0907 was a stability circRNA with lowly expression in OSCC. 
Overexpressed circ-KIAA0907 could inhibit migration, invasion, and glycolysis, 
while promoting apoptosis and radiosensitivity in OSCC cells. In the terms of 
mechanism, circ-KIAA0907 could sponge miR-96-5p to regulate UNC13C expression. 
MiR-96-5p overexpression could reverse the inhibitory effect of circ-KIAA0907 on 
OSCC progression, and UNC13C knockdown also could overturn the suppressive 
effect of miR-96-5p inhibitor on OSCC progression. Animal experiments revealed 
that circ-KIAA0907 could reduce the tumor growth of OSCC by regulating the 
miR-96-5p/UNC13C axis.
CONCLUSION: Our study suggests that circ-KIAA0907 restrains OSCC progression via 
the miR-96-5p/UNC13C axis, indicating that it may be a potential target for OSCC 
treatment.