Gene and protein expression levels of doxorubicin to doxorubicinol metabolizing enzymes. (A) Relative changes in expression between MCF-7CC12 and MCF-7DOX2-12 cells were assessed by RTqPCR. Each sample was normalized first to RPS28 for loading and then to the average expression of MCF-7CC12 cells to determine fold change. * p ≤ 0.05, ** p ≤ 0.01. (B) Western blot analysis of AKR1C3 expression in MCF-7DOX2-12 and MCF-7CC12 whole cell lysates.