Protein expression changes of ERα and two epigenetic modulators, HDAC1 and DNMT1 in mice breast tumors. Left panel, MDA-MB-231 breast tumor xenografts (Protocol 1); right panel, C3(1)-SV40 Tag transgenic mouse tumors (Protocol 2). A) Protein levels of ERα, DNMT1 and HDAC1 in breast tumors using western blot analysis. GE and/or TAM treatments were described in Materials and methods. Representative blots are presented from the independent experiments from all tumors per group with identical results. All the analyses in tumor samples were performed at the termination of the experiment. B) Histogram of quantification of the protein levels. Data are in triplicate from three independent experiments and were normalized to actin and calibrated to levels in control samples. Columns, mean; Bars, SD; *, P < 0.01, * * P < 0.001, significantly different from control.