Insulin

Human MCF7, T47D, and MDA-MB-231 BC cell lines were purchased from American Type Culture Collection (Manassas, VA). Human SUM159PT BC cell lines were purchased from Asterand (Detroit, MI). SUM159PT-ZsGreen-cODC, MCF7-ZsGreen-cODC, T47D-ZsGreen-cODC, and MDA-MB-231-ZsGreen-cODC were obtained as described by Vlashi et al.^{7 (link)} SUM159PT cells were cultured in log-growth phase in F12 Medium (Invitrogen, Carlsbad, CA) supplemented with 5% fetal bovine serum (Sigma-Aldrich, St. Louis, MO) and penicillin (100 units/mL) and streptomycin (100 μg/mL) cocktail (Invitrogen), 5 μg/mL insulin (Eli Lilly, Indianapolis, IN), 0.5% 1M hydroxyethyl piperazineethanesulfonic acid (Invitrogen), and 1 μg/mL hydrocortisone (Pfizer, New York, NY). T47D and MDA-MD-231 cells were cultured in log-growth phase in Dulbecco’s Modified Eagle Medium (Invitrogen) supplemented with 10% fetal bovine serum and penicillin (100 U/mL) and streptomycin (100 μg/mL) cocktail. MCF7 cells were cultured in log-growth phase in Minimum Essential Media Alpha (Invitrogen) supplemented with 10% fetal bovine serum and penicillin (100 U/mL) and streptomycin (100 μg/mL) cocktail, nonessential amino acids (1 ×; NEAA, Invitrogen), 1 mM sodium pyruvate (Invitrogen), and 5 μg/mL insulin (Eli Lilly). All cells were grown in a humidified incubator at 37°C with 5% CO₂.