Fig. 1

Identification and characterization of circRHOBTB3 in CRC. (A) Heatmap of differentially expressed circRNAs in sera from CRC, HCC, and PAAD patients compared with healthy donors. (B) Venn diagram of significantly upregulated circRNAs in CRC, HCC, and PAAD serum samples. (C) Expression of hsa_circ_000744 and its host gene in serum samples from CRC, HCC, PAAD patients and healthy donors. (D) Sketch map and primers for circRHOBTB3. (E) Sanger sequencing for confirmation of the specific back-splicing site of circRHOBTB3. (F) RNase R treatment, RT-PCR and RT-qPCR for confirmation of circRHOBTB3. (G) Detection of circRHOBTB3 in serum samples from CRC patients by RT-qPCR (levels normalized to those of GAPDH). (H) Detection of circRHOBTB3 and RHOBTB3 in paired normal and CRC tissue in the verification cohort by RT-qPCR (levels normalized to those of GAPDH). (I) Kaplan-Meier survival analysis of CRC patients according to the expression level of circRHOBTB3 using the log-rank test (n = 69). All experiments were repeated for three times, data were shown as mean ± SD, * P < 0.05, ** P < 0.01, *** P < 0.001, NS P > 0.05, in Student’s test (C, F, G), or paired Student’s test (H)