Cellular landscaping of exosomal miRNAs in cancer metastasis: From chemoresistance to prognostic markers

Exosomes are cargos facilitating the transport of miRNAs across cancer cells. Exosomal miRNA has been an area of interest in recent times due to their triple role in cancer proliferation. The current review discusses the triple role of exosomal miRNAs and proposes its application in diagnosis as a prognostic marker. Exosomal miRNAs are miRNAs found inside the exosomal structure of 30–150 nm of an extracellular vesicle. The synthesis and biogenesis of these exosomal miRNA involve an endosomal sorting complex required for transport which releases miRNAs and relevant proteins to cause tumor heterogeneity, drug resistance, and cancer metastasis. Herein, we have highlighted the role of exosomal miRNAs in both drug resistance and cancer metastasis. Additionally, we have elucidated the impact of exosomal miRNAs upon host immunity, which will provide us with the idea of host immune rejection. Furthermore, we have elaborated the clinical importance of exosomal miRNAs as a prognostic marker.