Physical and Molecular Landscapes of Mouse Glioma Extracellular Vesicles Define Heterogeneity

Abstract

Summary: Cancer extracellular vesicles (EVs) are highly heterogeneous, which impedes our understanding of their function as intercellular communication agents and biomarkers. To deconstruct this heterogeneity, we analyzed extracellular RNAs (exRNAs) and extracellular proteins (exPTNs) from size fractionation of large, medium, and small EVs and ribonucleoprotein complexes (RNPs) from mouse glioblastoma cells by RNA sequencing and quantitative proteomics. mRNA from medium-sized EVs most closely reflects the cellular transcriptome, whereas small EV exRNA is enriched in small non-coding RNAs and RNPs contain precisely processed tRNA fragments. The exPTN composition of EVs and RNPs reveals that they are closely related by vesicle type, independent of their cellular origin, and single EV analysis reveals that small EVs are less heterogeneous in their protein content than larger ones. We provide a foundation for better understanding of segregation of macromolecules in glioma EVs through a catalog of diverse exRNAs and exPTNs. : Extracellular vesicles (EVs) are highly heterogeneous. Using genetically defined mouse glioblastoma tumor cells, Gyuris et al. employ a differential filtration approach to isolate EVs based on size and establish the differential distribution of RNA and protein between EVs and ribonucleoprotein complexes in genetically distinct contexts. Keywords: extracellular RNA, proteome, extracellular vesicles, exosomes, glioblastoma, mouse model