Expression profile of circRNAs within extracellular vesicles (EVs) and their corresponding back-splicing ratio profile.

We identified 136,327 EV-circRNAs from various human body fluids. Significantly, a considerable amount of circRNAs with a high back-splicing ratio are highly enriched in EVs compared to linear RNAs. Notably, circSMARCA5 was among those with elevated expression levels, hinting at its utility as an EV molecular marker. Additionally, we discovered brain-specific circRNAs enriched in plasma EVs and cancer-associated EV-circRNAs linked to clinical outcomes. Importantly, we identified the involvement of RBPs, particularly YBX1, in the sorting mechanism of circRNAs into EVs.