Plasmatic exosome-derived circRNAs panel act as fingerprint for glioblastoma

Circular RNAs (circRNAs) have recently emerged as a new class of RNAs, highly enriched in the brain and very stable within cells, exosomes and body fluids. In this study, we aimed to screen the exosome derived circRNAs in glioblastoma multiforme (GBM) and investigate whether these circRNAs could predict GBM as potential biomarkers. The exosome was extracted from the plasma of GBM patients and healthy volunteers and validated by immunoblotting. The circRNA microarray was employed with three samples in each group to screen the dysregulated circRNAs isolated from the exosome. Five circRNAs were first selected as candidates with the upregulated level in exosome isolated from the plasma of GBM. Further validation found that only hsa_circ_0055202, hsa_circ_0074920 and hsa_circ_0043722 were consistent with training set. The Receiver operating characteristic (ROC) curve also revealed a high diagnostic ability an area under ROC curve value (AUC) for single circRNA and combined. The AUC for hsa_circ_0055202, hsa_circ_0074920, hsa_circ_0043722 and the combined was 0.810, 0.670, 0.938 and 0.988 in training set. For the validation set, the AUC was 0.850, 0.625, 0.750 and 0.925. The three circRNAs were further investigated with stable expression in human plasma samples. In conclusion, the exosome derived hsa_circ_0055202, hsa_circ_0074920 and hsa_circ_0043722 might be the potential biomarker for predicting the GBM.