Effects of CLA, Tam and E
on cell proliferation and apoptosis of ERα negative human breast epithelial cells. (A) and histogram in (C) are MTS assay for the effects of CLA, Tam and E2 for 3 days of treatment on cell proliferation of MDA-MB-231 and ERα negative normal human breast epithelial cells (ERα(-) NEC), respectively. (C) Western blot analysis of basal ERα protein expression in MCF-7 and primary cultured ERα negative normal human breast epithelial cells (ERα(-) NEC). Equal amounts of isolated protein from both cell extracts were subjected to immunoblot with anti-ERα antibodies. β-actin was used as loading control. Hoechst staining of (B) MDA-MB-231 and (E) ERα(-) NEC, and (D) Apo-ONE® homogeneous caspase-3/7 assay of ERα(-) NEC after 3 days of CLA, Tam and E2 treatment. CLA stands for 40 μM t10, c12-CLA. Tam stands for 1 μM 4-Hydroxytamoxifen; E2 stands for 10 nM 17β-estradiol. *p < 0.05 versus control. Docetaxel, the commonly used anti-cancer drug, was used as the positive control in the assay of cell proliferation and apoptotic activity.