Fig. 1

The characteristics of circMTCL1 in LSCC cells and tissues. a, The flowchart illustrating the selecting processes of circMTCL1 based on the sequencing data. b, A circular diagrams from the most inner circle to the most outer circle represent the log2 fold change value of up-regulated or down-regulated differentially expressed circRNAs of the LSCC compared with matched adjacent-tumor control tissues (n = 4, P < 0.05), the gene expression value of matched adjacent-tumor control tissues, the gene expression value of LSCC, the different chromosome location of the genes in different colors, and the ruler of chromosome. c, The scatter plots of circRNAs expression among included 4 pairs of LSCC tissues and their matched tumour-adjacent normal samples. The dashed lines represent 2.0-fold change. d, The volcanic plot of circRNAs expression among included 4 pairs of LSCC tissues and adjacent-tumor control tissues (n = 4, Log 2 FC = 2.0, P < 0.05). e, The hierarchical clustering heat map showing the most differentially expressed circRNAs in LSCC and corresponding paired adjacent-tumor control tissues, selected top 10 up-regulated or down-regulated genes (n = 4, P < 0.05). Red in heat map represents upregulation. Blue represents downregulation. f, The ideograph illustrating the genomic location and splicing mode of circMTCL1. The splicing junction site was confirmed by sanger sequencing. g, The RNA enzyme digestion test was performed to validate the stability of circMTCL1 in TU212 and LCC cells. h, The expression level of circMTCL1 in 67 pairs of LSCC tissues and their ANM samples was assessed by qRT-PCR assays. Values are the mean ± s.d. of n = 3 independent experiments. i, The expression level of circMTCL1 in normal control HaCaT cell and LSCC cells including TU212, LCC, LLN was detected by qRT-PCR assays. Values are the mean ± s.d. of n = 3 independent experiments. j, Localization of circMTCL1 detected by FISH assay in TU212 and LCC cells. Scale bar = 50 μm. k, The expression level of circMTCL1 within the TU212 and LCC cells amplifying with isolated RNA from the cytoplasmic contents and cell nuclei was detected by qRT-PCR assays. Values are the mean ± s.d. of n = 3 independent experiments. l, The receiver operating characteristic (ROC) curve showing the diagnostic cut-off value of circMTCL1 expression. m, The log-rank test was explored to investigate the impact of the circMTCL1 expression level on the survival of patients with LSCC. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001