miR-193b Modulates Resistance to Doxorubicin in Human Breast Cancer Cells by Downregulating MCL-1
Transfection of miR-193b sensitized MCF-7/DOXR cells to doxorubicin. (a) MCF-7 and MCF-7/DOXR cells were treated with different concentrations of doxorubicin, and cell viability was assayed by using MTT. The IC50 was determined according to the survival curves, which showed the MCF-7/DOXR cell line got a 17.0-fold acquired resistance to doxorubicin compared to the MCF-7 cell line (6.560 ± 0.412 versus 0.386 ± 0.051 μg/mL, ). (b) MCF-7/DOXR cells were seeded in 6-well plates and transfected with miR-193b mimic or NCO, and the miR-193b expression level was assayed by qPCR. versus NCO group. (c) MCF-7/DOXR cells were treated with different concentrations of doxorubicin plus miR-193b or NCO, and cell viability was assayed by using MTT. The IC50 was significantly lower in MCF-7/DOXR cells transfected with miR-193b as compared to the cells transfected with NCO, . (d) MCF-7/DOXR cells were treated with 1.2 μg/mL doxorubicin plus miR-193b or NCO, and cell apoptosis was detected by Annexin V/PI staining. Data are expressed as the means ± SE (). .