Figure 1. Characterization and validation of circSPIDR expression in CADC. (A) Violin plot showing the distribution of the RNA sequencing reads of circSPIDR in normal cervical tissues (Norm) and CADC tissues. (B) The genomic locus and generation of circSPIDR. CircSPIDR is produced from exons 6 and 7 of the human SPIDR gene. The back-splice junction sequence of circSPIDR was detected using Sanger sequencing. (C) qRT-PCR analysis of circSPIDR expression in 20 normal cervical tissues and 20 CADC tissues. (D) Northern blot of circSPIDR. Hybridization was performed with exon 6–7 junction probes. M, RNA marker; 1–3, HeLa cell repeats; 4, CADC tissue; 5, Normal cervical tissue; 6, RT-PCR products of probes. (E) qRT–PCR analysis of circSPIDR expression and SPIDR mRNA expression in HeLa cells with or without RNase R treatment. (F) RT-PCR products of circSPIDR and its linear isoform (SPIDR) in cDNA and gDNA from HeLa cells. GAPDH was used as a control. NS, not significant; *P < 0.05; **P < 0.01; ***P < 0.001.