MiR-200c Sensitizes Breast Cancer Cells to Carboplatin Treatment by Decreasing MDR1 Expression

Abstract Background: Breast cancer (BC) is one of the most common cancers worldwide and is associated with a high rate of cancer mortality in women. Resistance to chemotherapy is considered a significant problem and a major challenge for the treatment of patients with BC. miR-200c belongs to a family of miRNAs that act as tumor inhibitors. The expression level of miR-200c has been reported to be decreased in cancers, especially in BC. The increased miR-200c expression can be considered as a potent inhibitor of drug resistance and tumor progression. Methods and Results: The current study examined the effect of miR-200c on enhancing the BC cells' sensitivity to Carboplatin through targeting MDR1 expression. To perform functional analyses, mimic miR-200c transfected to MCF7 cells. Then, the viability of the cells was investigated via MTT assay. Finally, the expression of associated genes assessed using qRT-PCR. The results indicated that downregulation of miR-200c was occurred in MCF7 cells in comparison to control. Besides, restoring miR-200c expression by regulating the expression level of the apoptotic gene reduces the viability of cancer cells. Moreover, miR-200c increased the sensitivity of MCF7 cells to Carboplatin via reducing the MDR1 gene expression. Conclusions: This study provided valuable data showing that miR-200c enhances the effect of carboplatin as a clinically approved chemotherapeutic agent, and restoring its expression could be considered as a promising targeted adjuvant therapy for BC management.