Exosomes, the extracellular vesicles produced in the endosomal compartments, facilitate the transportation of
proteins as well as
nucleic acids. Epigenetic modifications are now considered important for fine-tuning the response of
cancer cells to various
therapies, and the acquired resistance against targeted
therapies often involves dysregulated epigenetic modifications. Depending on the constitution of their cargo, exosomes can affect several epigenetic events, thus impacting post-transcriptional regulations. Thus, a role of exosomes as facilitators of epigenetic modifications has come under increased scrutiny in recent years. Exosomes can deliver
methyltransferases to recipient cells and, more importantly, non-coding RNAs, particularly
microRNAs (
miRNAs), represent an important exosome cargo that can affect the expression of several oncogenes and
tumor suppressors, with a resulting impact on
cancer therapy resistance. Exosomes often harbor other non-coding RNAs, such as long non-coding RNAs and
circular RNAs that support resistance. The exosome-mediated transfer of all this cargo between
cancer cells and their surrounding cells, especially tumor-associated macrophages and cancer-associated fibroblasts, has a profound effect on the sensitivity of
cancer cells to several chemotherapeutics. This review focuses on the exosome-induced modulation of epigenetic events with resulting impact on sensitivity of
cancer cells to various
therapies, such as,
tamoxifen,
cisplatin,
gemcitabine and
tyrosine kinase inhibitors. A better understanding of the mechanisms by which exosomes can modulate response to
therapy in
cancer cells is critical for the development of novel therapeutic strategies to target
cancer drug resistance.