Abstract
Lidocaine can inhibit the malignant development of various human cancers. Circular RNA (circRNA) dynein 1 heavy chain gene (circ_DYNC1H1) acted as a pro-cancer molecule in hepatocellular carcinoma (HCC). This study aimed to explore whether the function of lidocaine was related to the oncogenic circ_DYNC1H1 in HCC. Colony formation assay and 3-(4,5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay were used for proliferation detection. Cell apoptosis was assessed by flow cytometry, and migration or invasion was determined by the transwell assay. The levels of circ_DYNC1H1, microRNA-520a-3p (miR-520a-3p), and ubiquitin-specific protease 14 (USP14) were examined using the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Protein levels were measured using western blot. The binding between miR-520a-3p and circ_DYNC1H1 or USP14 was confirmed by the dual-luciferase reporter assay. In vivo assay was conducted by a xenograft model in mice. Lidocaine reduced proliferation, migration, and invasion but promoted apoptosis in HCC cells. The circ_DYNC1H1 expression was downregulated in lidocaine-treated HCC cells. The inhibitory effect of lidocaine on HCC progression was weakened after circ_DYNC1H1 overexpression. miR-520a-3p was a target of circ_DYNC1H1, and the function of lidocaine was related to the regulation of circ_DYNC1H1/miR-520a-3p axis. USP14 served as a target for miR-520a-3p, and circ_DYNC1H1 could sponge miR-520a-3p to regulate the USP14 expression. The lidocaine-induced suppression of HCC development was also achieved by mediating the miR-520a-3p/USP14 axis. In vivo assay revealed that lidocaine suppressed the tumor growth of HCC by reducing the expression of circ_DYNC1H1 to affect the levels of miR-520a-3p and USP14. Our results clarified that lidocaine impeded tumor progression via targeting the circ_DYNC1H1/miR-520a-3p/USP14 axis in HCC cells.