Extracellular vesicle-mediated suicide mRNA/protein delivery inhibits glioblastoma tumor growth in vivo

Extracellular vesicles (EVs) are considered as important mediators of intercellular communication, which carry a diverse repertoire Of genetic information between cells. This feature of EVs can be used and improved to advance their therapeutic potential. We have previously shown that genetically engineered EVs carrying the suicide gene mRNA and protein cytosine deaminase (CD) fused to uracil phosphoribosyltransferase (UPRT)-inhibited schwannoma tumor growth in vivo. To further examine whether this approach can be applied to other cancer types, we established a subcutaneous xenograft glioblastoma. tumor model in mice, as glioblastoma represents the most common primary brain tumor, which is highly aggressive compared with the original schwannoma tumor model U87-MG glioblastoma cells were implanted into the flanks of nude SCID mice, and the animals were intratumorally injected with the EVs isolated from the cells expressing EGFP or CD-UPRT. After the intraperitoneal administration of the prodrug 5-fluorocytosine, the tumor growth was assessed by regular caliper measurements. Our data revealed that the treatment with the CD-UPRT-enriched EVs significantly reduced the tumor growth in mice. taken together, our findings suggest that EVs uploaded with therapeutic CD-UPRT mRNA/protein may be a useful tool for glioblastoma treatment

Lymphatic exosomes promote dendritic cell migration along guidance cues

Lymphatic endothelial cells (LECs) release extracellular chemokines to guide the migration of dendritic cells. In this study, we report that LECs also release basolateral exosome-rich endothelial vesicles (EEVs) that are secreted in greater numbers in the presence of inflammatory cytokines and accumulate in the perivascular stroma of small lymphatic vessels in human chronic inflammatory diseases. Proteomic analyses of EEV fractions identified >1,700 cargo proteins and revealed a dominant motility-promoting protein signature. In vitro and ex vivo EEV fractions augmented cellular protrusion formation in a CX3CL1/fractalkine-dependent fashion and enhanced the directional migratory response of human dendritic cells along guidance cues. We conclude that perilymphatic LEC exosomes enhance exploratory behavior and thus promote directional migration of CX3CR1-expressing cells in complex tissue environments