Breast Cancer Cell Line Analyses with Fatty Acids and EVOO Compounds

For in vitro analyses, we used the MCF-7 cell line, representing the molecular subtype of human breast cancer Luminal A, and MDA-MB-231 cells, representing the triple-negative subtype. Cell lines were obtained from the American Type Culture Collection (ATCC; LGC Standards, Middlesex, UK). MCF-7 cells were grown in EMEM (Gibco, Thermo Fisher Scientific, Waltham, MA, USA) and supplemented with 10% fetal bovine serum (FBS; Gibco) and 0.01 mg/mL of insulin. MDA-MB-231 cells were grown in DMEM (Gibco) and supplemented with 10% FBS. Cells were maintained at 37 °C in a humidified atmosphere of 95% air and 5% CO₂. The cell cultures were subjected to Mycoplasma screen tests periodically.
For fatty acid treatments, oleic acid- or linoleic acid-albumin from bovine serum (Sigma-Aldrich, Merck KGaA, Darmstadt, Germany) were used at 0 µM (control), 1 µM, 10 µM, 100 µM, or 1 mM concentration. All the solutions contained 0.1 mg/mL of BSA (Sigma-Aldrich).
For treatments with EVOO minor compounds, we used hydroxytyrosol (PHL80152, Sigma Aldrich) at 0 µM (control), 100 µM, 250 µM, and 400 µM; oleuropein (12,247, Sigma Aldrich) at 0 µM (control), 10 µM, 30 µM, and 50 µM; and lutein (L9283, Sigma-Aldrich) at 0 µM (control), 5 µM, 10 µM, and 30 µM [25 (link),26 (link),27 (link)]. All the solutions contained 0.1% of DMSO.