Extracellular vesicles (EVs):roles in cell proliferation and transcriptomic analysis of HUVEC receiving cancerderived EVs

Abstract:  Extracellular vesicles (EVs) are released by almost  all types of cells. EVs play an    important role in cell-to-cell communication by sending biomolecules such as mRNAs to    other cells via endocytosis. This project aims to understand the roles of EVs and their    potential application as mRNA delivery vehicles by completing two objectives. One       objective was to investigate the EVs’ roles in cell proliferation by routinely removing EVs    from cell-conditioned media, transferring stress-induced EVs to recipient epithelial cells, and examining their cell number. Another objective was to analyzethe transcriptomic expression of HUVEC cells treated with breast-cancer-derived EVs. EVs were routinely removed from the cell culture using 100 kDa filters, 15 kDa filters, or by changing to new media. The result showed that the epithelial cancer cell line grows at a lower growth rate when EVs are removed using 100 kDa filters and 15 kDa filters compared to the control. The stressinduced EV transfer experiment showed no significant difference in cell number among different stress conditions and stress-EV treatment. The transcriptomic analysis revealed 765 differentially expressed genes, which were mapped onto pathways using the IPA software. The majority of the top 10 significant pathways were associated with cancer progression. IPA’s Biomarker Filter function revealed 35 cancer biomarkers, as well as 33 putative angiogenesis biomarkers. VEGFAtargeted genes were identified, and the ones that are upregulated and located in the extracellular matrix or plasma membrane were identified as putative biomarkers for VEGFA-induced angiogenesis. The top 10-pathways suggest that the recipient HUVEC may receive cancer-related messages from the EVs. It is important to evaluate the content of EVs derived from different origins thoroughly. Cancer-derived EVs may induced angiogenesis in HUVEC, as shownpreviously, but cancer EVs might also communicate cancer signals that can cause pathological effects. Extensive studies and validation are needed to fully understand the role of EVs and their application as an mRNA delivering system.