Exosomes: Pros and cons for fighting cancer

Exosomes (Exo) are extracellular vesicles involved in intercellular communication. These nanovesicles are a mini reflection of the cell of origin, carrying several bioactive molecules, also reflecting the conditions of the extracellular environment. Exo can be a double-edged sword depending on their origin, so that tumor cell-derived Exo may be loaded with important tumor antigens to be presented to the immune system, but may also decrease the immunotherapeutic action of monoclonal antibodies. Moreover, tumor Exo carry many molecules with suppressive potential, subverting the immune response. Alternatively, Exo originating from antigen-presenting cells (APCs) such as dendritic cells (DCs) may directly or indirectly induce tumor-specific T lymphocyte response, both in vitro and in vivo, being clinically safe. Another clinically attractive factor of Exo is its use as a noninvasive liquid biopsy, which may facilitate diagnosis in the early phase of the disease. In addition, they can be used as biotechnological tools for loading bioactive drugs.