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