Fig. 1

The secondary sequencing information of differential circRNA profiles from the LSCC samples. a The percentage of significantly differentially expressed circRNAs arising from different genomic locus (exonic, intronic, antisense, intragenic, and intergenic). b Volcano plot. X-axis: the fold change expressed as log2; Y-axis: P value expressed as -log10. The vertical green lines corresponded to 2.0-fold up and down, and the horizontal green line represented a p-value of 0.05. The red points in the plot represented circRNAs that were expressed differentially with statistical significance. c Hierarchical clustering of the circRNA expression data according to ‘All Targets Value’. It classified the samples into different groups based on their expression levels. It revealed a distinguishable circRNA expression profiling among the samples used in this study. d & e The overlapping significantly changed circRNAs in LSCC versus the normal adjacent tissue. There were 20 significantly downregulated (d) and 9 upregulated (e) circRNAs in the LSCC versus the normal adjacent tissues (yellow area). There were 24 significantly downregulated (d) and 10 upregulated (e) circRNAs in moderately differentiated tumors versus the normal adjacent tissues (green area). There were 21 significantly downregulated (d) and 15 upregulated (e) circRNAs in well differentiated tumors versus the normal adjacent tissues (red area). Integrating these three comparisons, we found 18 overlapping significantly downregulated and 5 upregulated circRNAs in LSCC versus the normal adjacent tissues. These 23 significantly changed circRNAs were detailed in Additional file 1: Table S3