ObjectiveTo investigate the effects of circ_0005379 on the proliferation, apoptosis, migration, and invasion of oral squamous cell carcinoma (OSCC) cells and its mechanism.
MethodsReal-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of circ_0005379 and miR-17-5p in OSCC tissues and SCC15 cell lines. Western blot was used to detect the expression levels of acyl-CoA oxidase 1 (ACOX1). The circ_0005379 overexpression vector was transfected into SCC15 cells. Methyl thiazolyl tetrazolium blue staining, flow cytometry, Transwell, and Western blot were used to detect the effects of circ_0005379 overexpression on the proliferation, apoptosis, migration, and invasion of SCC15 cells and the expression of E-cadherin, β-catenin, and Snail proteins. Dual luciferase reporter assay and RNA immunoprecipitation were used to examine the regulation of circ_0005379, miR-17-5p, miR-17-5p, and ACOX1 in SCC15 cells. A nude mouse xenograft model of SCC15 cells stably overexpressing circ_0005379 was established, and the effect of circ_0005379 overexpression on the growth of xenografts in nude mice was observed.
ResultsCompared with adjacent cancer tissues, the expression levels of circ_0005379 and ACOX1 proteins in OSCC tissues were decreased (P<0 .05), and the expression level of mir-17-5p was increased (P<0 .05). compared with hok-16a cells, the expression levels of circ_0005379 and acox1 proteins in scc15 cell lines were decreased (P<0 .05), and the expression level of mir-17-5p was increased (P<0 .05). after overexpressing circ_0005379, the activity and number of migrating and invading scc15 cells and the expression levels of β-catenin and snail proteins were decreased (P<0 .05); however, the apoptosis rate and expression level of e-cadherin protein were increased (P<0 .05). in scc15 cells, circ_0005379 targeted the negative regulation of mir-17-5p expression, and mir-17-5p targeted the negative regulation of acox1 expression. overexpressing mir-17-5p or silencing acox1 could reverse the effects of circ_0005379 overexpression on the proliferation, apoptosis, migration, and invasion of oscc cell lines. the tumor volume and weight of nude mice overexpressing circ_0005379 were decreased (P<0 .05), the expression levels of circ_0005379 and acox1 protein in tumor tissues were increased (P<0 .05), and the expression level of mir-17-5p was decreased (P<0 .05).
Conclusioncirc_0005379 may inhibit the proliferation, migration, and invasion of OSCC cells by downregulating the expression of miR-17-5p and upregulating ACOX1, which promote apoptosis and inhibit tumor growthin vivo. circ_0005379 may be a potential target for OSCC treatment.
