Figure 2. Characteristics and clinical significance of circ_0006332. (A) The diagram shows the structure and the splice junction of circ_0006332. Direct Sanger sequencing data shows that circ_0006332 is spliced out at the GC junction between exons 8 and 9 of the MYBL2 precursor mRNA transcript. (B) Agarose gel electrophoresis shows PCR products obtained from circRNA and linear mRNA samples after digestion with Ribonuclease R. The results show that the PCR primer was specific for the circRNAs and circRNAs were resistant to digestion by the exonuclease. (C) Representative FISH images show that circ_0006332 is located in the cytoplasm of bladder cancer cells. Scale bar: 50 μm. (D) Quantitative RT-PCR analysis of circ_0006332 expression in 32 paired specimens of bladder cancer and adjacent normal bladder tissues is shown. The expression is represented by the delta cycle threshold (ΔCT). Lower ΔCT value corresponds to high expression of circ_0006332. (E) Quantitative RT-PCR analysis shows MYBL2 mRNA expression in 32 coupled specimens of bladder cancer and adjacent normal bladder tissues. (F) Receiver operating characteristic (ROC) curve analysis of circ_0006332 expression in the clinical diagnosis of bladder cancer. The area under the curve (AUC) value: 0.860, sensitivity: 80.2%, specificity: 86.0%. (G) ROC curve analysis of MYBL2 expression in the clinical diagnosis of bladder cancer. The AUC value: 0.885, sensitivity: 81.3%, specificity: 84.6%. Note: Data were represented as mean ± SD; ***P < 0.001.