Objective:To investigate the expression of microRNA (miRNA, miR)-4699-3p in ovarian cancer cell lines, and observe its ability to regulate the expression of mitochondrial ribosomal protein S23 (MRPS23) and its effect on the migration and proliferation of ovarian cancer cells.Methods:Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-4699-3p in ovarian cancer cell lines (OVCAR-3, SKOV-3, HO-8910, OC3, A2780) and normal ovarian epithelial cells (IOSE80). The liposome transfection method was used to transfect miR-4699-3p mimic or negative control miR-NC to the cell line with the lowest miR-4699-3p expression, which was defined as the experimental group and the control group. qRT-PCR was used to verify transfection efficiency. Bioinformatics technology predicted the candidate target gene of miR-4699-3p, and the dual luciferase reporter gene experiment identified its ability to regulate the target gene. qRT-PCR and Western blot were used to detect the expression of target genes at the mRNA and protein levels. Cell counting method (CCK-8) and transwell migration experiment were used to detect the effect of miR-4699-3p on the proliferation and migration of ovarian cancer cells.Results:The expression of miR-4699-3p in ovarian cancer cell lines was significantly lower than that of normal ovarian epithelial cells ( P<0.05), and the lowest expression in OVCAR-3 cells ( P<0.01). After transfection of miR-4699-3p, the expression of miR-4699-3p in OVCAR-3 cells in the experimental group was significantly increased ( P<0.01), which proved that the transfection was successful. Bioinformatics technology predicted that the candidate target gene of miR-4699-3p may be MRPS23. The dual luciferase reporter gene experiment confirmed that miR-4699-3p can directly target the 3′-UTR of MRPS23 gene mRNA ( P<0.01). Compared with the OVCAR-3 cells in the control group, the mRNA and protein expression levels of the MRPS23 gene were significantly reduced, while the expressions of Twist, Slug, CDK6 and Cyclin D3 were significantly decreased ( P<0.01) in the experimental group after up-regulating miR-4699-3p expression ( P<0.01). After up-regulating miR-4699-3p expression, the proliferation ability of OVCAR-3 cells decreased ( P<0.05) and the migration ability of OVCAR-3 cells was reduced ( P<0.01). Conclusions:miR-4699-3p is under-expressed in ovarian cancer cell lines. Up-regulation of miR-4699-3p expression in OVCAR-3 cells can inhibit ovarian cancer cell proliferation and migration by interfering with MRPS23 gene expression.