Fig. 1: circWDR62 expression is upregulated in TMZ-resistant glioma and expression is significantly correlated with poor prognosis.

A Representative electron micrograph images of exosomes secreted by U343-R and U343 cells. B NTA analysis of the concentration and size distribution of exosomes secreted by U343-R and U343 cells. C WB analysis showing the expression levels of the exosome markers CD63 and TSG101 in exosomes secreted by U343-R and U343 cells. D Volcano plot showing thousands of differentially expressed circRNAs in U343-R-exos compared to U343-exos. E Heatmap showing differentially expressed circRNAs in U343-R-exos vs. U343-exos. hsa_circ_0050688 was one of the most upregulated circRNAs (red arrow). F The structure of hsa_circ_0050688 and the genomic position and chromosomal localization of the host gene WDR62 according to the UCSC genome browser (http://genome.ucsc.edu/). G Schematic representation of circWDR62. H qRT–PCR was conducted to determine the relative expression of circWDR62 and WDR62 upon RNase R treatment. I qRT–PCR was conducted to determine the expression of circWDR62 within serum exosomes in patients with primary tumours and recurrent tumours after TMZ-based chemotherapy and normal controls. J qRT–PCR was conducted to determine the expression of circWDR62 within tissues in patients with primary tumours and recurrent tumours. K Kaplan–Meier survival analysis of patients with recurrent glioma was conducted according to the expression of circWDR62 using the log-rank test. L qRT–PCR assay was conducted to verify the expression of circWDR62 in U343-R and U251-R cells after with shRNA-circWDR62. M The mRNA expression of WDR62 after transfection of shRNA-circWDR62.