Cell culture experiments. Cell lines were obtained from the Rio de Janeiro Cell Bank that certified their identity and quality (Inmetro, Rio de Janeiro, RJ, Brazil). Human breast adenocarcinoma cell lines (MCF-7, MDA-MB-231 and MDA-MB-235) were plated in 25 cm2 cell culture flasks at a density of 5.0×106 cells/flask, and maintained in DMEM supplemented with 10% fetal bovine serum (FBS)