Figure 7.

Several potential anticancer drugs (dihydroartemisinin and artesunate) in reversing the doxorubicin resistance of breast cancer in vitro. (A) The effect of dihydroartemisinin, artesunate, and doxorubicin on the proliferation inhibition rate of MCF-7 parental and its doxorubicin-resistant cell, MCF-7/ADM, was quantified by the CCK-8 method. Inhibition rate was calculated as the difference in optical density (OD) at 450 nm between the control and experimental group (OD₄₅₀) divided by OD₄₅₀ in the control group and then multiplied by 100%. (B) RT-qPCR analysis of the levels in cells, and corresponding quantification of the ATG7 and LC3B mRNA levels. (C–E) An immunofluorescence assay was used to detect ABCG2, ATG7, and LC3B proteins in MCF-7/ADM cells. MCF-7/ADM was untreated or treated with ADM (2 μmol/L)/ART (20μmol/L)/DHA (20 μmol/L) and combined group (ART+ADM) for 48 h Proteins were stained green, and nuclei were stained blue with 4,6-diamidino-2-phenylindole (DAPI). The images were captured at 200× magnification. (F) The immunofluorescence results (using mean fluorescence intensity) to reflect the changes in protein expression levels. (G) Western blot analysis of the ATG7 protein levels in MCF-7/ADM, and corresponding quantification of the ATG7 protein. *p < 0.05, **p < 0.01 vs. the control group.