To observe the expression of microRNA-221 (miR-221) in ovarian cancer tissues and its effect and associated mechanism on proliferation and apoptosis in the ovarian cancer SKOV3 cell line. The expression of miR-221 and B-cell lymphoma 2 modifying factor (BMF) mRNA in ovarian cancer and para-carcinoma tissues was detected by reverse transcription-quantitative polymerase chain reaction, the expression of BMF was detected by western blot. MicroRNA.org online predicted that BMF was the possible target gene of miR-221, and the regulatory association was validated by a dual-luciferase reporter gene assay. SKOV3 cells were divided into 8 transfection groups: Anti-miR-negative control (NC); anti-miR-221; phosphorylated internal ribosome entry site 2 (pIRES2)-blank, pIRES2-BMF, small interfering (si)-NC, si-BMF, anti-miR-221+si-BMF and anti-miR-221+pIRES2-BMF groups. Cell proliferation was detected by EdU staining flow cytometry. The effect of transfection on cell apoptosis was detected by Annexin V/PI double staining, and the activity of caspase-3 was detected by spectrophotometry. The effect of anti-miR-221 or pIRES2-BMF transfection on SKOV3 cell proliferation was detected by MTT assay and flow cytometry, and the effect on apoptosis was detected by the Annexin V/PI double staining. Compared with para-cancer tissues, the miR-221 expression was significantly upregulated (P<0.001), the BMF mRNA expression was significantly downregulated (P<0.001), and the expression of BMF proteins was significantly downregulated in the ovarian cancer tissues. Dual-luciferase reporter gene assay confirmed a targeted regulatory association between miR-221 and BMF. The anti-miR-221 or pIRES2-BMF transfection significantly upregulated BMF expression in SKOV3 cells, significantly decreased cell proliferation and significantly increased cell apoptosis. The overexpression of BMF may enhance the proapoptotic and proliferation-inhibition effect of anti-miR-221 on SKOV3 cells. The transfection of si-BMF significantly promoted cell proliferation, reduced cell apoptosis and attenuated the proapoptotic and proliferation-inhibition effect of anti-miR-221 on cells. The expression of miR-221 was significantly upregulated and the expression of BMF was significantly down-regulated in ovarian cancer tissues. The overexpression of miR-221 antagonized the apoptosis of ovarian cancer SKOV3 cell and promoted the cell proliferation by targeted inhibition of the expression of BMF, which may serve a role in the pathogenesis of ovarian cancer.
Keywords: B-cell lymphoma 2 modifying factor; apoptosis; ovarian cancer; proliferation.