Figure 7. Ethanol increases the mitochondrial activity in MCF7 cancer cells. (A) MCF7 cells were cultured in the presence or in the absence of 100 mM EtOH for 72 h. Western blot analysis using antibodies against subunits of the mitochondrial OXPHOS respiratory chain (complexes I–V). β-actin is shown as equal loading control. Note that ethanol significantly increases the expression of OXPHOS complex I (20 kDa subunit) and IV (COX-II) in MCF7 cancer cells. (B) Immunocytochemistry. MCF7 cell-fibroblast co-cultures were treated with 100 mM EtOH for 72 h. Cells were fixed and immunostained with antibodies against the mitochondrial membrane marker TOMM20 and K8/18. Nuclei were counterstained with DAPI (blue). The upper panels show the mitochondrial staining (red). The bottom panels show also the K8/18 staining (green), to identify the MCF7 cell population. Note that ethanol increases the mitochondrial mass specifically in MCF7 cells, as compared with untreated cells. However, ethanol does not promote mitochondrial biogenesis in fibroblasts. Original magnification, 40x.