Extracellular Vesicles Carrying miR-887-3p Promote Breast Cancer Cell Drug Resistance by Targeting BTBD7 and Activating the Notch1/Hes1 Signaling Pathway

Figure 2

MDA-MB-231-derived EVs promoted BC cell drug resistance. (a) The survival of MCF-7, HCC1937, and BT474 cells in different concentrations of doxorubicin (Dox), cisplatin (Cis), and fulvestrant (Ful) was detected using CCK-8 assay. Then, the BC cells were treated with 15 μg/mL MDA-MB-231-derived EVs (EV-group) or MDA-MB-231 supernatant supplemented with GW4869 (NC group), or PBS as a negative control (blank group). (c) Fluorescence microscope showed the uptake of EVs (15 μg/mL) labeled with the red fluorescent dye PKH26 by MCF-7, BT474, and HCC1937 cells after 24 h of stimulation. Next, MDA-MB-231-derived EV-treated parental or drug-resistant BC cells were exposed to 0.5 μM doxorubicin, 2.5 μM cisplatin, and 0.5 μM fulvestrant, respectively. Then, CCK-8 assay (c), colony formation assay (d), and flow cytometry (e) were performed to determine the effect of MDA-MB-231-derived EVs on BC cell drug resistance. Data are expressed as the ; one-way ANOVA and Tukey’s multiple comparison test were used to determine statistical significance. . Three independent experiments were performed. BC: breast cancer; CCK-8: cell counting kit-8; ANOVA: analysis of variance.

(a)

(b)

(c)

(d)

(e)