Abstract: OBJECTIVE To investigate the relationship between the miR-182 and the cisplatin-resistance in breast cancer. METHODS MTT assay was performed to evaluate the role of miR-182 in cisplatin-induced cell death in MCF-7 cells. Bioinformatics, quantitative PCR and Western blot analysis was performed to determine whether the gene of BNIP3 was regulated by miR-182. JC-1 staining, Annexin V staining and Western blot analysis were performed to study the pathway of cell death induced by miR-182 inhibitors plus cisplatin in MCF-7. RESULTS MiR-182 mimics impaired the anti-tumor effect of cisplatin. In contrast, the anti-tumor effect of cisplatin was significantly enhanced when the miR-182 inhibitors were transfected into MCF-7 cells. The results of Western blot and RT-PCR indicated that the BNIP3 gene was the target of miR-182. Furthermore, the apoptosis caused by miR-182 inhibitors plus cisplatin was dependent on the decrease of mitochondrial membrane potential and the activation of caspase-3 in MCF-7 cells. CONCLUSION MiR-182 influences the anti-tumor effect of cisplatin in breast cancer by reducing the expression of BNIP3.