1.1.1.2. Exosomal miRNAs and Epithelial-mesenchymal transition (EMT):
Epithelial-mesenchymal transition (EMT) is a process in which cancer cells acquire increased motility and tremendous plasticity, caused by loss of cell junctions and apical-basal polarity and acquisition of mesenchymal characteristics [72, 73]. EMT cells are directly related to metastasis, cancer progression, and drug resistance in various cancers because they have an extremely invasive phenotype [74]. There is ample evidence to demonstrate that the EMT process in the TME can be modulated by exosomes released from cancer cells [41, 75, 76]. Xiao et al. showed that exosomal miRNAs involved in regulating EMT, such as miR-191 and let-7a derived from melanoma, induced EMT in primary melanocytes [77]. Additionally, studies have shown that exosomal miRNAs are involved in activating or stabilizing EMT in primary tumor cells [36].