Exosomes in melanoma: a role in tumor progression, metastasis and impaired immune system activity.

Exosomes in melanoma: a role in tumor progression, metastasis and impaired immune system activity. Oncotarget. 2018 Apr 17;9(29):20826-20837 Authors: Tucci M, Mannavola F, Passarelli A, Stucci LS, Cives M, Silvestris F Abstract Exosomes (Exo) are small vesicles produced by melanoma cells and the accessory cells of the tumor microenvironment. They emerge via both classical and direct pathways and actively participate in tumor colonisation of distant tissues. The proteins, nucleic acids, cytokines and growth factors engulfed by Exo are transferred to recipient cells, where they drive numerous functions required for the tumor escape from immune system control and tumor progression. By positively or negatively modulating immune cell properties, Exo provoke immune suppression and, in turn, defective dendritic cell (DC) functions. Together, these effects limit the cytotoxicity of T-cells and expand both T-regulatory and myeloid-derived suppressor populations. They also hinder perforin and granzyme production by natural killer cells. Finally, Exo also control the organotropism of melanoma cells. The distinct phenotypic properties of Exo can be exploited both for diagnostic purposes and in the early identification of melanoma patients likely to respond to immunotherapy. The potential therapeutic application of Exo derived from DCs has been demonstrated in vaccination trials, which showed an increase in anti-melanoma activity with respect to ...
Source: Oncotarget - Category: Cancer & Oncology Tags: Oncotarget Source Type: research