Culturing Breast Cancer Cell Lines

The human breast adenocarcinoma cell lines MCF-7 (ATCC® HTB-22) and MDA-MB-231 (ATCC® HTB-26) and the breast epithelial cells MCF-10A (ATCC® CRL-10317) were acquired from the American Type Culture Collection (ATCC). MCF7 cells were cultured in Eagle's Minimum Essential Medium (EMEM; ATCC) and MDA-MB-231 cells were cultured in high glucose Dulbecco's Modified Eagle's Medium (DMEM; Sigma-Aldrich), whereas MCF-10A cells were cultured in 1 : 1 mixture DMEM: F-12 medium (ATCC) supplemented with 20 ng/mL epidermal growth factor (EGF; Gibco, Thermo Fisher Scientific), 0.01 ng/mL insulin (Sigma-Aldrich), 500 ng/mL hydrocortisone (Sigma-Aldrich), and 5% fetal bovine serum (FBS; Gibco, Thermo Fisher Scientific). Tumorigenic cell lines were supplemented with 10% FCS. 1% penicillin/streptomycin mixture (Pen/Strep, 10,000 IU/ml; Sigma-Aldrich) was added in each cell culture medium to avoid a possible fungal/microbial contamination. Standard conditions were used for cell culture—37°C and humidified atmosphere containing 5% CO₂, as previously described before [34 (link), 35 (link)].