*5.1. Cell Culture and Maintenance*

MCF7 and MDA-MB-231 breast cancer cell lines were previously acquired from ATCC (Manassas, VA, USA) and maintained at our laboratory cell bank. Cells were thawed and cultured at 37 ◦C in 5% CO2 in RPMI 1640 culture medium (Gibco, Life Technologies, Grand Island, NY, USA) supplemented with 10% inactivated fetal bovine serum (Cultilab, Campinas, Brazil) and 25 mg/mL ampicillin and 100 mg/mL streptomycin antibiotics. Cells were split when the confluence reached 80%.
