Extracellular vesicles (EVs) are membrane-bound particles shed from nearly all cell types into the extracellular environment. This collective term includes vesicles ranging in size from 30 nm to 5 μm in diameter. Various isolation techniques are used in different studies to separate EVs with no consensus protocol. EVs are released from cells under normal physiological conditions as well as in stressful and pathological conditions. In malignancies, they have been shown to be useful circulating markers for risk assessment, early diagnosis, monitoring of therapeutic effectiveness and prognosis. In addition, they appear to influence cell death and growth, angiogenesis, immune surveillance, extracellular matrix degradation and metastasis. In this respect, EVs have generated considerable interest for their potential use in cancer therapeutics. Since they appear to be responsible for transference of cellular components between cells and thereby transfer of functional characteristics of the donor to the recipient, two strategies for their role in cancer therapeutics may be envisaged. The first would be to prevent formation and/or shedding of EVs to prevent communication to or from cancer cells. The second would be to utilize them as carriers to deliver inhibitory/toxic components into cancer cells to destroy or neutralize them. In this review, we discuss the current state of research on characterization of EVs and highlight possible strategies for their use in cancer therapy.
Part of the book: Tumor Metastasis