Engineered Retinal Pigment Epithelial Cells

The hTERT-immortalized human retinal pigment epithelial cells (hTERT-RPE-1) were obtained from ATCC (Manassas, VA) and grown in DMEM/F12, 1:1 (Gibco, Thermo Fisher Scientific Inc., Waltham, MA, USA) medium supplemented with 10% foetal bovine serum (Gibco, Thermo Fisher Scientific Inc., Waltham, MA, USA), penicillin/streptomycin (Gibco, Thermo Fisher Scientific Inc., Waltham, MA, USA), and 0.01 mg/ml hygromycin-B (Millipore Sigma, Darmstadt, Germany). The cells were tagged with mEmerald-vimentin using the TALEN genome editing approach, which has been previously described^{29 (link)}. For imaging, the cells were placed into collagen as previously described^{21 (link)}. MV3 cells were obtained from Peter Friedl (MD Anderson Cancer Center, Houston TX). The MV3 cells were cultured in DMEM (Gibco, Thermo Fisher Scientific Inc., Waltham, MA, USA) supplemented with 10% foetal bovine serum (Thermo Fisher Scientific Inc., Waltham, MA, USA) at 37 °C and 5% CO₂. The cells were infected to express GEMs using a lentiviral construct from Addgene (Plasmid #116934^{22 (link)}). The cells were sorted by fluorescence activated cell sorting to purify the population of cells expressing GEMs.