Poster Session - Abstract # 1

Characterization of Circulating Extracellular Vesicles Released in Plasma from Colorectal Cancer Mouse Model

Luis A. Arteaga-Blanco and Dan A. Dixon

Department of Molecular Biosciences, University of Kansas Cancer Center, University of Kansas, Lawrence, Kansas, USA

Colorectal cancer (CRC) is in the top 10 cancers most prevalent worldwide, affecting men and women. Current research on tumor-derived extracellular vesicles (EVs) suggests that populations of EVs (large EVs, LEV and Small EVs, SEV) play an important role in cellular communication through the transport of bioactive molecules to recipient cells and thus potentially modulate cancer progression via multiple pathways.  In this study, we isolated and characterized circulating LEV and SEV released by plasma from wild type or the CRC mouse model ApcMin/+.  EVs were separated by differential centrifugation and then were described using nanoparticle tracking analysis (NTA), scanning electron microscopy (SEM) and western blot.  Mice-derived plasma secreted LEV with size ranging from 70-550 nm, peaking at 240 nm and SEV with size ranging from 50–150 nm, peaking at 120 nm, as evaluated by NTA and SEM.  The markers CD63 and CD81 were detected by immunoblotting in the preparations indicating the presence of EVs in the samples.  Our results showed that pellets enriched with LEV and SEV from Apc^Min/+ mice presented higher particle concentration (4 and 3 orders of magnitudes, respectively) and protein concentration compared with vesicles from normal mice.  These initial findings provide relevant information for further studies to explore the role of tumor-derived EVs from CRC mice models and their ability to modulate cancer progression.  We believe that an in-depth analysis and omics characterization of these EV subtypes from cancer mice models may be useful to identify proteins or molecules associated with tumor development and candidate biomarkers for CRC diagnosis.

Keywords: CRC, Extracellular vesicles, cellular communication.