Murine Model for Triple Negative Breast Cancer

4T1 cells (American Type Culture Collection—ATCC), a widely used triple negative breast cancer cell line [18 (link),19 (link)] and a murine model for stage IV human breast cancer, were grown at 37°C with 5% CO₂ in RPMI-1640 supplemented with 10% fetal bovine serum (FBS), 100 units/mL penicillin and 50 g/mL streptomycin, all from GIBCO (Grand Island, NY). MDA-MB-231 and MDA-MB-468, also triple negative breast cancer cell lines, however, derived from human breast tumors, were purchased from ATCC and cultivated at 37°C with 5% CO₂ in DMEM medium supplemented with 10% FBS, 100 units/mL penicillin and 50 g/mL streptomycin. HEK293 cells, used for adenoviral expansion, were grown at 37°C with 5% CO₂ in DMEM supplemented with 10% FBS, 100 units/mL penicillin and 50 g/mL streptomycin, all from GIBCO (Grand Island, NY). Female Balb/C mice at 7–8 weeks (approximately 25-30g) were used for in vivo experiments. Animal care and experimental procedures were complied with Universidade Federal de Minas Gerais—Comissão de Ética no Uso de Animais (CEUA)—institutional animal welfare established guidelines (CEUA/UFMG/Approval 88/2013). Animals were maintained on a standard diet and water access ad libitum and housed under a 12-hour light–dark cycle.