Mass cytometric and transcriptomic profiling of epithelial-mesenchymal transitions in human mammary cell lines
Epithelial-mesenchymal transition (EMT) equips breast cancer cells for metastasis and treatment resistance. Detection, inhibition, and elimination of cells that are undergoing EMT is challenging due to the intrinsic heterogeneity of cancer cells and the phenotypic diversity of EMT programs. We comprehensively profiled EMT transition phenotypes in four non-cancerous human mammary epithelial cell lines using a FACS surface-marker screen, RNA sequencing, and mass cytometry. EMT was induced in the HMLE and MCF10A cell lines and in the HMLE-Twist-ER and HMLE-Snail-ER cell lines by prolonged exposure to TGFβ1 or 4-hydroxytamoxifen, respectively. Each cell line exhibited a spectrum of EMT transition phenotypes, which were compared to steady-state phenotypes of fifteen luminal and basal breast cancer cell lines. Our data provide multiparametric insights at the single-cell level into the phenotypic diversity of EMT at different time points for the four human cellular models, shedding light on the complexity of EMT and enabling comparisons of EMT transitions between cellular models and design of EMT time course experiments.