LAUSR

BACKGROUND Accumulating articles have suggested the important regulatory roles of circular RNAs (circRNAs) in human cancers, including oral squamous cell carcinoma (OSCC). However, the role of circ_0001971 in OSCC progression remains to be determined. METHODS 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays were conducted to analyze cell proliferation ability. Cell migration and invasion abilities were assessed by transwell assays. Dual-luciferase reporter assay was conducted to confirm the target relation between miR-107 and circ_0001971 or FZD4. Xenograft tumor model was established to analyze the biological role of circ_0001971 in regulating tumor growth in vivo. RESULTS Circ_0001971 was markedly up-regulated in OSCC tissues and cell lines. Circ_0001971 knockdown inhibited the growth of xenograft tumors in vivo. miR-107 was confirmed as a direct target of circ_0001971, and circ_0001971 depletion-mediated anti-tumor effects in OSCC cells could be largely alleviated by silencing miR-107. miR-107 directly targeted the 3' untranslated region (3'UTR) of FZD4, and FZD4 overexpression largely reversed the anti-tumor effects of circ_0001971 in OSCC cells. Circ_0001971 could positively regulate FZD4 expression by targeting miR-107 in OSCC cells. CONCLUSION Circ_0001971 promoted the proliferation, migration, and glycolysis of OSCC cells through mediating miR-107/FZD4 axis. Circ_0001971 might be a new effective target for OSCC treatment in future.