Overexpression of circFNDC3B promotes the progression of oral tongue squamous cell carcinoma through the miR-1322/MED1 axis.

Background: The potential role of circFNDC3B in regulating oral tongue squamous cell carcinoma development (OTSCC) remains unknown.

Methods: The level of circFNDC3B in OTSCC tissues or cell lines was measured and its function in vitro and in vivo was analyzed. Interactions among circFNDC3B, miR-1322, and MED1 were verified by luciferase reporter and RNA pull-down assays.

Results: The level of circFNDC3B in tissues or cell lines of OTSCC was higher than that in control groups. siRNA-mediated circFNDC3B inhibition resulted in weakened proliferation, migration, and invasion, which was reversed by miR-1322. Overexpression of MED1 in OTSCC cells partially reversed the tumor suppression functions of si-circFNDC3B or miR-1322 mimics in vitro. circFNDC3B overexpression dramatically promoted tumor growth in vivo. circFNDC3B directly bound with miR-1322 and consequently promoted the MED1 expression in OTSCC cells.

Conclusions: The circFNDC3B/miR-1322/MED1 axis participates in OTSCC progression, which may provide novel therapeutic targets for OTSCC.