Fig. 1

circPTN was upregulated in glioma tissues and glioma cell lines. a. The heat map of circRNAs in 27 glioma tissues vs. 19 NBT. b. The volcano plot of circRNAs expressed in glioma tissues vs. NBT; red plots represent circRNAs, which were at least 1.5-fold higher expression in glioma tissues than NBT (*p < 0.05). c. The heat map of 15 circRNAs, which were significantly upregulated in glioma tissues than NBT (> 1.5 fold, *p < 0.05). d. CircRNA expression in glioma cell lines and astrocyte-HEB cells. Compared with that in HEB cells, circCLIP2, circFANCL and circPTN were significantly upregulated in all glioma cell lines. (n = 3, *p < 0.05, ANOVA). e. circPTN was significantly upregulated in glioma tissues compared with NBT in both Song et al. cohort and Zhujiang Hospital cohort (30 glioma tissues vs. 7 NBT, *p < 0.05, t test); f. Schematic illustration showed that the circularization of PTN exons 2–4 formed circPTN. g. circPTN was resistant to RNase R treatment, whereas linear RNA-PTN and GADPH were not. (n = 3, mean ± SEM). h. qPCR for the abundance of circPTN and PTN in U251 cells treated with actinomycin D (2 μg/mL) at indicated time points. (n = 3, mean ± SEM). i. Nuclear-cytoplasm separation qPCR data suggested that circPTN was primarily localized in the cytoplasm. U6 almost located in the nucleus. (n = 3, mean ± SEM). j. By performing FISH, the images showed that circPTN existed in both cytoplasm and nucleus, but primarily localized in the cytoplasm in U251 cells; scale bar