miR-200c increases the sensitivity of breast cancer cells to Doxorubicin through downregulating MDR1 gene

Background: Breast cancer (BC) has been known as the most common type of cancer worldwide and resulted in death among women. BC is usually resistant to standard therapies that are significant problems in managing BC patients. miR-200c belongs to the miRNA family, which is considered as a tumor suppressor with reduced expression levels in various kinds of cancer like BC. Increased expression of miR-200c has been reported as a potent inhibitor of drug resistance and tumor advancement. The purpose of this paper is to examine the outcome of miR-200c restoring on enhancing the BC cells' sensitivity to Doxorubicin through downregulating the MDR1 expression. Methods: Initially, MDA-MB-231 cells were transfected with miR-200c to perform functional analyses. After that, MTT assay was performed to investigate the viability of the cell. Finally, qRT-PCR was used to assess gene expression. Results: According to the results, the miR-200c expression was downregulated in BC cells compared to control. Moreover, the cell viability was reduced in transfected cells via regulation in gene expression associated with apoptosis. Furthermore, miR-200c could increase the BC cells' sensitivity to Doxorubicin by reducing the MDR1 gene expression. Conclusion: Hence, this study's findings recommend that miR-200c can consider as a method of therapy for the treatment of BC.