MiR-200b-5p inhibits proliferation of ovarian cancer cells by targeting ATAD2 and regulating PI3K/AKT signaling pathway.

OBJECTIVE: The purpose of this study was to investigate the influences of micro ribonucleic acid (miR)-200b-5p on proliferation and apoptosis of ovarian cancer (OC) cells, and to explore its correlations with the target gene ATPase family, AAA domain containing 2 (ATAD2), and the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. MATERIALS AND METHODS: Human ovarian fibroblasts (HOFs) or human OC cell lines (A2780) were cultured in vitro, and then, A2780 cells were separately transfected with miR-200b mimics or miR-NC or cultured with ATAD2-specific inhibitor BAY-850. Thereafter, the expression levels of miR-200b and ATAD2 messenger RNA (mRNA) were measured via qRT-PCR, and the proliferative capacity of cells was detected by CCK-8 assay. Next, the cell apoptosis was determined by means of flow cytometry and one-step TUNEL assay. Finally, the targeted regulatory relationship between miR-200b and ATAD2 was examined using a Luciferase reporter assay system, and the protein expressions were detected through Western blot (WB) assay. RESULTS: It was found that the expression level of miR-200b was remarkably lower (p<0.05), while the mRNA expression level of ATAD2 was notably higher (p<0.05) in A2780 cells than those in HOFs. The transfection with miR-200b mimics markedly reduced the mRNA expression level of ATAD2 (p<0.05) and the proliferative capacity (p<0.05) and increased the apoptosis rate (p<0.05) of A2780 cells. Besides, it was detected via the Luciferase reporter assay system that miR-200b inhibited ATAD2. BAY-850 significantly decreased the expression level of ATAD2 protein (p<0.05) and the proliferative capacity (p<0.05) but improved the apoptosis rate (p<0.05) of cells. Moreover, both miR-200b mimics and BAY-850 could distinctly repress the protein expression levels of PI3K and p-Akt of the PI3K/Akt signaling pathway (p<0.05) and enhance the expression of suppressor gene p53 (p<0.05). CONCLUSIONS: MiR-200b-5p can inhibit the proliferation and promote the apoptosis of OC cells through targeted inhibition of ATAD2 expression and regulation of the PI3K/Akt signaling pathway.