Effect of miR-200c replacement in sensitization of breast cancer cells to Cytarabine

Abstract

Breast cancer is one of the most common cancers in women and discovering novel treatments for it is of high importance. One of the main obstacles in breast cancer treatment is acquired chemoresistance. miR-200c is associated with decreased chemoresistance in many cancers. In this study, we aimed to evaluate the effect of miR-200c restoration on sensitization of breast cancer cells to cytarabine. Methods: The human breast cancer cell line MDA-MB-468 was transfected with miR-200c through electroporation. MTT assay was conducted to measure the effect of cytarabine on cell viability and proliferation of miR-200c transfected cells. To evaluate the effect of miR-200c and cytarabine on cell cycle progression, flowcytometry was performed. In order to evaluate the gene expression of c-Myc, Cyclin-D1, and p21, the qRT-PCR (qRT-PCR) was carried out. Results: MTT assay results indicated that miR-200c restoration and its combination with cytarabine sensitized MDA-MB-468 cells to the drug, which resulted in inhibition of cell proliferation. Moreover, restoration of miR-200c led to the cell cycle arrest at sub-G1 phase. In addition, the data obtained from qRT-PCR manifested reduced c-Myc, Cyclin D1 exression, and enhanced p21 level, meaning that miR-200c inhibited MDA-MB-468 cells growth, through increasing cell's sensitivity to the chemotherapy drug and regulating cell cycle-related genes.