Transcriptomic Characterization, Chemosensitivity and Regulatory Effects of Exosomes in Spontaneous EMT/MET Transitions of Breast Cancer Cells

Background/Aim: We examined the gene expression changes of breast cancer cells spontaneously undergoing epithelial–mesenchymal transition (EMT) and its reverse process mesenchymal–epithelial transition (MET) and the role of exosomes in these transitions. Materials and Methods: Highly invasive mesenchymal-like breast cancer cells, MDA-MB-231 (basal cells), EMT and MET variants, were characterized by microarray gene expression profiling, immunocytochemistry and chemo-sensitivity. Results: Spontaneously disseminated cells were anoikis resistant, exhibited a dissociative, EMT-like phenotype and underwent MET when reseeded in cell-free plates. MET was inhibited by exosomes secreted by basal cells. Chemo-sensitivity to doxorubicin, vincristine and paclitaxel decreased in the order EMT