Fig. 1

a Circos plot showed the locations of cricRNA on human chromosomes. The outermost layer was a chromosome map of the human genome. The inner 8 circles represented all circRNAs of each sample detected by RNA-seq. The inner circles from outside to inside corresponded to sample N3, N4, N5, N6, T3, T4, T5, and T6, respectively. The bar chart presented the expression levels of circRNA. b The scatter plot presented the circRNA expression variations between CRC and control groups. The values of the X and Y axes represented the normalized circRNA signal values (log2 scaled). The circRNAs above the top black line and below the bottom black line displayed greater than two-fold change of up- and down-regulation. c Heatmap of inter-sample correlation showed there was an obvious difference of significantly dysregulated circRNA expression levels between CRC and control groups, but the difference was slight within each group. The Pearson’s correlation coefficient was represented by a color scale. The intensity increased from blue (relatively lower correlation) to red (relatively higher correlation). Correlation was evaluated by Pearson’s correlation coefficient of significantly dysregulated circRNA expression levels. d Volcano plot displayed the dysregulated circRNAs between CRC and control groups. The vertical gray lines corresponded to two-fold up- and down-regulation (log2 scaled), and the horizontal gray line represented a p value of 0.05. The red points represented significantly up-regulated circRNAs in CRC, and the green points represented significantly down-regulated circRNAs in CRC. e Classification of the significantly dysregulated circRNAs based on genomic origin. f Hierarchical clustering of the dysregulated circRNAs in CRC. The expression values were represented by a color scale. The intensity increased from green (relatively lower expression) to red (relatively higher expression). Each column represented one tissue sample, and each row represented a single circRNA. T, CRC tumor tissues; N, adjacent normal mucosa tissues