MicroRNA-424 serves an anti-oncogenic role by targeting cyclin-dependent kinase 1 in breast cancer cells

The aim of the present study was to define the function of microRNA-424-5p (miR-424) in breast cancer cells. The present study investigated the level and the potential function of miR-424 in breast cancer by reverse transcription-quantitative polymerase chain reaction assays. miR-424 expression was decreased in the majority of human breast cancer specimens and cell lines used in the present study. The MTT assay, plate colony formation assay and flow cytometry analyses were used to characterize the function of miR-424 in two types of breast cancer cell lines. Upregulation of miR-424 inhibited cellular proliferation and regulated the cell cycle by arresting cells in the G2/M cell phase. The dual-luciferase reporter assay was used to confirm the direct association between miR-424 and cyclin-dependent kinase 1 (CDK1). Silencing of CDK1 expression by CDK1 short interfering RNA also significantly suppressed cell proliferation and arrested cells in the G2/M cell phase. The results of the present study indicated that miR-424 can suppress cell proliferation and arrest cells in G2/M cell phase by negatively regulating CDK1 mRNA in human breast cancer, possibly through the Hippo pathway and the extracellular signal-regulated kinase pathway. The results of the present study provided novel evidence for the role of miR-424 in breast cancer.