Epithermal growth factor

The human breast cancer cell line JIMT-1 (ACC589) was purchased from the German Collection of Microorganisms and Cell Cultures (DSMZ) and was routinely maintained in Dulbecco's modified Eagle's medium/nutrient mixture Ham's F12 medium (VWR, Lund, Sweden). The human breast cancer cell lines MCF-7 (HTB-22), HCC1937, and human normal-like breast epithelial cell line MCF-10A (CRL-10317) were obtained from American Type Culture Collection (Manassas, VA, USA) and were cultured in RPMI1640 medium (VWR). The JIMT-1, MCF-7, and HCC1937 cell lines were cultured with the addition of 10% fetal calf serum (FCS) (VWR), nonessential amino acids (1 mM) (VWR), insulin (10 μg mL⁻¹) (Sigma-Aldrich), penicillin (100 U mL⁻¹) (VWR), and streptomycin (100 μg mL⁻¹) (VWR). In addition, HCC1937 cell line was also supplemented with epidermal growth factor (20 ng mL⁻¹) (Sigma-Aldrich). The MCF-10A cells were cultured with the addition of 10% heat-inactivated FCS, nonessential amino acids (1 mM), insulin (10 μg mL⁻¹), penicillin (100 U mL⁻¹), streptomycin (100 μg mL⁻¹), epithermal growth factor (20 ng mL⁻¹), cholera toxin (50 ng mL⁻¹) (Sigma-Aldrich), and hydrocortisol (250 ng mL⁻¹) (Sigma-Aldrich). All cell lines were maintained at 37 °C in a humidified incubator with 5% CO₂.