Establishment of a bioluminescent MDA-MB-231 cell line for human triple-negative breast cancer research

The aim of this study was to establish a bioluminescent MDA-MB-231 cell line stably expressing luciferase and green fluorescent protein for the generation of a xenografted model of human triple-negative breast cancer (TNBC) in nude mice. Lentivirus vectors carrying eGFP, firefly luc2 and neo fusion genes were used to transduce the MDA-MB-231 human TNBC cells in vitro. After 8 weeks of G418 selection, eGFP and luc2 expression was determined using a fluorescence microscope and a Xenogen IVIS200 bioluminescent imaging system, respectively. The MTT, transwell invasion and wound healing assays were performed to confirm whether cellular proliferation, invasion and migration were altered by lentiviral infection. Cells were orthotopically implanted into female BALB/c nude mice to test the sensitivity and stability of reporter gene expression. Growth of the tumors was monitored with the in vivo imaging system once a week until they were large enough for experiments. The tumor tissues were resected for histology, and cancer cells were harvested for culture. The lentivirus-transduced MDA-MB-231 cells could stably express luc2 and eGFP, and the luciferase activity reached 9689 photons/sec/cell. Meanwhile, no significant difference in biological activities was observed between the lentivirus-transduced MDA-MB-231 cells and parental cells. An orthotopically implanted tumor model of human TNBCs was successfully established in BALB/c nude mice. Lentiviruses may be ideal carriers for luciferase genes due to their highly efficient infectivity and stable transgene expression. The modified MDA-MB-231 cell line stably expressing luciferase could be detected, allowing for immediate and sensitive detection of metastasis sites in nude mice. As the eGFP and luc2 combination are superior to single reporter genes in their ability to mark cells in vivo and in vitro, these cells may provide a visualizable, convenient and sensitive platform for research on the mechanisms of metastasis and the development of new antitumor drugs for human TNBC.