Fig. 1

Characterization of circESRP1 in EC. a CircRNAs with significant upregulation were selected based on the criteria of fold change > 2 and P value < 0.01 by using a heatmap and volcano plot. In the volcano plot, red dots indicate circRNAs with increased expression in EC, and green dots indicate circRNAs with decreased expression in EC. b The expression of the differentially highly expressed circRNAs was validated in EC and normal tissues by RT-qPCR. c The figure illustrates that circESRP1 is backspliced into a loop by exons 7–9 of ESRP1, and Sanger sequencing confirms the back-spliced junction sites. d The presence of circESRP1 was verified by qRT-PCR in Ishikawa cells and RL952 cells. Different primers amplified circESRP1 in cDNA rather than genomic DNA (gDNA). e The relative RNA levels of Ishikawa cells upon exposure to actinomycin D were analysed by qRT-PCR. f The relative RNA levels of Ishikawa cells and RL952 cells treated with or without RNase R were analysed by qRT-PCR. g Cytoplasmic and nuclear distribution of circESRP1 in Ishikawa cells was analysed by qRT-PCR. 18S and U6 served as positive controls for the cytoplasm and nucleus, respectively. h Identification of circESRP1 location by FISH in Ishikawa cells and RL952 cells. 18S and U6 were used as positive controls in the cytoplasm and nucleus, respectively. i qRT-PCR analysis of circESRP1 in tumour tissues and normal endometrial tissues. Scale bar: 10 μm. n = 3, *P < 0.05, **P < 0.01, ***P < 0.001