The goal of the present study was to capture and characterize circulating tumor cells (CTC) from mouse models of triple-negative breast cancer (TNBC), a highly recalcitrant disease. CTCs were captured by size-based filtration from orthotopic nude-mouse models of the human MDA-MB-231-GFP cell line.
Subsequently, CTCs were cultured for a 3 months period in vitro. Cyto-morphological analysis with confocal microscopy demonstrated heterogeneity among the CTCs, which alternated between adherent in culture.
CTC gene-expression analysis was performed with qPCR for 20 tumor-associated markers from RNA derived from adherent/nonadherent CTCs in culture. Both Fox3p and TWIST1 were highly expressed in non-adherent CTCs.
The present study demonstrates the power of size-based CTC isolation from orthotopic mouse models of TNBC and GFP imaging of viable CTC cells in culture, to characterize highly-heterogeneous TNBC CTC.