MiR-20b-5p Targets KIF23 to Suppress Cell Proliferation and Migration in Osteosarcoma

Background: MicroRNAs (miRNAs) are closely correlated with the development of cancer. Here, the main goal of this study was to analyze the biological function of miR-20b-5p in osteosarcoma (OS). Methods: : The expression of miR-20b-5p and kinesin family member 23 (KIF23) was determined using quantitative real time PCR and western blot analysis, respectively. The correlation between miR-20b-5p or KIF23 expression and the clinicopathological characteristics of OS was evaluated using Chi-square test. Functional experiments, including CCK-8, flow cytometry and transwell assay were performed to analyze cell proliferation, cell cycle distribution and apoptosis, and migration. The association between miR-20b-5p and KIF23 was confirmed by luciferase reporter assay. Results: : Firstly, we observed that miR-20b-5p expression was significantly decreased, while kinesin family member 23 (KIF23) expression was increased in OS tissues. Moreover, miR-20b-5p expression was inversely correlated with KIF23 expression in OS tissues. Clinically, decreased miR-20b-5p expression was significantly associated with increased metastasis and increased KIF23 mRNA expression level was remarkedly correlated with increased tumor size. Overexpression of miR-20b-5p significantly suppressed cell proliferation and migration, as well as caused G0/G1 phase arrest and apoptosis in OS cells (U2OS and MG-63). Mechanistically, miR-20b-5p directly targeted to the 3’-UTR of KIF23 and negatively regulated its expression in OS cells. Moreover, KIF23 knockdown imitated, while overexpression abolished the effects on U2OS cell proliferation, G1/S transition, apoptosis and migration induced by miR-20b-5p overexpression. Furthermore, KIF23 overexpression reversed the miR-20b-5p-induced downregulation of CDK4, Cyclin D1, Bcl-2, PCNA, Ki-67 and N-cadherin, as well as upregulation of Bad and E-cadherin in U2OS cells. Conclusions: : In conclusion, miR-20b-5p directly targeted the 3'UTR of KIF23 mRNA to inhibit the proliferation and migration of human OS cells in vitro , which might be a promising candidate target for OS treatment.