Fig. 1

circCCDC134 was significantly upregulated in CC tissues. A and B Heatmap and scatterplot results showed that there were hundreds of circRNA expression differences in CC tissue. C The circular structure of circCCDC134 was confirmed by amplification with divergent primers, followed by Sanger sequencing, which showed that circCCDC134 was generated from exon 2 to exon 6 of the CCDC134 gene through back splicing. D We verified the circular feature of circCCDC134 and conducted qRT–PCR using oligo (dT) and random primers, and the results suggested that compared with the random primers, circCCDC134 expression was noticeably reduced, while CCDC134 expression did not change when using the oligo (dT) primers, revealing that circCCDC134 contained no poly-A tail. E and F RNase R and G: actinomycin D suggested that circCCDC134 was more stable than linear CCDC134. H and I circCCDC134 was found in both the nucleus and cytoplasm via FISH and RNA fractionation assays. J and K The qRT–PCR results revealed circCCDC134 overexpression in 24 tumour and 10 metastatic tissues and CC cells