Figure 2.

Induction of HO‐1 expression mediated pharmorubicin resistance in breast cancer cells. A, MTT assay revealed that the cell survival of MDA‐MB‐231/EP1 and MCF‐7/EPI was higher than MDA‐MB‐231 and MCF‐7 cells after being treated with pharmorubicin. B, The mRNA level in MDA‐MB‐231, MDA‐MB‐231/EP1, MCF‐7 and MCF‐7/EPI cells increased significantly after being treated with pharmorubicin. C, The expression of HO‐1, LC3‐II/LC3‐I and Beclin‐1 was up‐regulated in four group of cells after pharmorubicin treatment. D, The increase in pharmorubicin‐induced autophagy in four cell lines was observed by cell autophagy analysis, scale bar: 20 μm. *P < 0.05, **P < 0.01, compared with pharmorubicin (‐) or MDA‐MB‐231/MCF‐7 groups