Extracellular vesicle sampling and small RNA analysis from high grade glioma patient plasma for the identification of novel biomarkers and development of organotypic cultures as an ex vivo model for extracellular vesicle production

Abstract

High grade glioma (HGG) tumours secrete extracellular vesicles (EVs) for paracrine signaling into plasma or growth media (in the case of cultured tissues). Isolation of these EVs and their cargo could help to better understand HGG biology, and aid to inform on diagnosis and disease course. Plasma-EVs were captured utilizing a peptide affinity method from HGG patients and normal controls followed by next generation sequencing and in silico analyses to define and characterize a HGG small RNA (sRNA) signature. Over 750 differentially expressed sRNA were identified between HGG and controls. The sRNA signature included lncRNA RPPH1 (Ribonuclease P Component H1), which informed on surgical resection and clinical progression. Additionally, organotypic slice cultures were generated from matched study patients from which conditioned culture media (CCM) EVs could be subsequently isolated and analyzed. The present study supports the role of plasma-EV sRNA sampling in a multi-pronged approach to HGG disease course surveillance.