Fig. 3

Overexpression of miR-4532 increased adriamycin resistance in MCF-7 cells. a After transfection with miR-4532 negative control (red), the cells were washed three times with PBS and then observed under a fluorescence microscope with a ×400 lens. b qPCR results showed that the expression of miR-4532 was significantly increased in MCF-7 cells transfected with the miR-4532 mimic (***p < 0.01, Student’s t-tests). c After transfection with miR-4532 mimic or negative control (NC) for 48 h, MCF-7 cells were subsequently treated with various concentrations of adriamycin for 48 h. Cell viability was determined using CCK-8 assays, and the calculation of IC₅₀ was obtained by using Probit regression analysis in SPSS 18.0 software (IC₅₀ for mimic and negative control group was 3.457 ± 0.274 and 0.603 ± 0.108 μg/ml, respectively, p < 0.05). d Overexpression of miR-4532 in MCF-7 cells rescued adriamycin-induced apoptosis after 48 h of treatment with 1 μM adriamycin, the rate of early apoptosis of NC group and mimic group was 31.21% and 10.09%, respectively, p < 0.01