MicroRNA-224Modulates Chemosensitivity Of Breast Cancer Cells To Docetaxel By API-5

Background and Aims.The view that microRNA-224(miR-224) may lead to tumorigenesis has been accepted in many studies. However, its role remains unclear in modulating the chemosensitivity of breast cancer cells to docetaxel (DOC). Then, the aim of this study was to estimate how miR-224plays in the chemosensitivity of breast cancer cells to DOC.Methods.The role of miR-224in breast cancer cells was analyzed using CCK-8assay, real-time PCR, flow cytometry assay and Western blot. Dual-luciferase reporter assay and API-5-siRNA technology were performed to analyze the association between miR-224and Apoptosis inhibitor5(API-5). Results.Overexpression of miR-224could significantly decrease the chemosensitivity of MCF-7breast cancer cells to DOC. The luciferase activity of MCF-7/DOC cells containing wild-type3’UTR of API-5could be inhibited by miR-224mimics. Similarly, the chemoresistance of MCF-7cells to DOC induced by miR-224mimics could be partially reversed by API-5-siRNA. Further, it had an inverse association between miR-224and API-5in breast cancer cells. Conclusion.Dysregulation of miR-224plays a vital role in the acquired DOC resistance of breast cancer and at least via targeting API-5partially.