Fig. 1

Identification and characterisation of circEMB in OSA cells. a Cluster heatmap demonstrating the expression levels of circRNA based on sequencing results. b qRT-PCR analysis of candidate genes correlated with tumour invasion and metastasis. c Sanger sequencing showing the circEMB loop formation characteristics. The circEMB sequence in the circBASE database was verified to contain seven exons (954) from the EMB gene. d Relative expression levels of circEMB in OSA cell lines and normal osteoblasts were determined via qRT-PCR. e After treatment with or without RNase R in 143B and U2OS cells, resistance exonuclease digestion of circEMB and EMB were determined by qRT-PCR. f The presence of circEMB in 143B and U2OS cells was determined via agarose gel electrophoresis. circEMB was amplified in cDNA instead of gDNA. GAPDH was used as the negative control. g-h The expression of circEMB and reference genes (GAPDH and U6) in the cytoplasm and nucleus was verified via nuclear plasma separation assay. circEMB was highly abundant in the cytoplasm. i circEMB localisation was analysed via FISH using a Cy3-labelled oligonucleotide. Scale bar, 50 μm. Data are expressed as mean ± SD (n = 3) (*, p < 0.05; **, p < 0.01; ***, p < 0.001)