Fig. 1

CircNUP50 was upregulated in ovarian cancer (OC) platinum-resistant tissues/cells. A Heatmap of circular RNA (circRNA) sequencing of platinum-resistant and platinum-sensitive OC tissues. B Scatterplot showed hundreds of circRNA expression differences in platinum-resistant and -sensitive OC tissue. C Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis based on circRNA-seq data. D The circular structure of circNUP50 was confirmed by amplification with divergent primers, followed by Sanger sequencing, which showed that circNUP50 was generated from exon 6 of the NUP50 gene through back splicing. E The circular structure of circNUP50 and the absence of a poly(A) tail of circNUP50 were verified using oligo (dT) and random primers. F and H RNase R and actinomycin D expression suggested that circNUP50 was more stable than linear NUP50. G Fluorescence in situ hybridisation experiments demonstrated that circNUP50 was present in the nucleus and cytoplasm of cells. I and J The qRT-PCR results revealed circNUP50 overexpression in OC platinum-resistant tissues and cells