Mda mb 231

The human breast cancer cell lines MCF-7 and MDA-MB-231 were obtained from the Korea Cell Line Bank (KCLB, Seoul, Korea). Both cell lines were grown in Dulbecco’s Modified Essential Medium (DMEM; HyClone, Logan, UT, USA) supplemented with 10% fetal bovine serum (FBS; HyClone), 100 U/mL of penicillin, and 100 μg/mL of streptomycin (HyClone), and were maintained at 37 °C in a humidified incubator containing 5% CO₂. We used breast cancer cell lines up to 15 passages after purchasing cell lines from KCLB and the cell lines were authenticated by the KCLB and showed >90% similarity in a short tandem repeats (STR) DNA fingerprint profile when compared with the American Type Culture Collection (ATCC) and Korean Cell Line Bank (KCLB) databases. Cells were plated at a density of 1 × 10⁶ cells in 10-cm culture dishes. To establish primary mammospheres, single-cell suspensions of MCF-7 and MDA-MB-231 cells were seeded at a density of (3.5∼4) × 10⁴ and (0.5∼1) × 10⁴ cells/well, respectively, in ultralow attachment six-well plates containing 2 mL of complete MammoCult^TM medium (StemCell Technologies; Vancouver, BC, Canada), which was supplemented with 4 μg/mL of heparin, 0.48 μg/mL of hydrocortisone, 100 U/mL of penicillin, and 100 μg/mL of streptomycin. The cells were incubated for seven days in a 5% CO₂ incubator at 37 °C.

Two cancer cell lines, MCF-7 and MDA-MB-231, were purchased from the American Type Culture Collection (ATCC; Manassas, VA, USA). We followed the method of [32 (link)]. Two cancer cell lines were grown in Dulbecco's modified essential medium (DMEM; HyClone, Logan, UT, USA) with 10% fetal bovine serum (FBS; HyClone), 100 U/mL penicillin, and 100 μg/mL streptomycin (HyClone). Two breast cancer cell lines were maintained at 37°C in a humidified incubator with 5% CO₂. Cells were plated at a density of 1 × 10⁶ cells in T75 culture flasks. For mammosphere formation, single cell-suspended cancer cell lines were seeded at a density of 4 × 10⁴ (MCF-7) and 1 × 10⁴ cells (MDA-MB-231)/well in ultralow-attachment 6-well plates containing 2.5 mL of complete MammoCult™ Medium (Stemcell Technologies). Two breast cancer cell lines were incubated in a 5% CO₂ incubator at 37°C for 7 days.