Fig. 1
SOX17 mRNA expression, DNA methylation and protein expression correlate with CCRT response in 70 ESCC patients. a Concordance analysis of low SOX17 mRNA expression and high SOX17 methylation in non-responders ESCC patients. The percentage of ESCC cases is indicated in the plot. P-value was calculated by Pearson χ2-test. b Inverse correlation between DNA methylation and mRNA expression in SOX17 gene. DNA methylation level of tumor (Log10(T)) tissues is indicated in the Y-axis, while tumor mRNA expression (Log10(T)) is plotted as the X-axis. One circle symbolizes one patient sample. Correlation coefficients (r) and P value were calculated by Pearson correlation coefficient analysis and are shown at the top. c Representative IHC of SOX17 protein in endoscopic biopsy sample from four ESCC patients. SOX17 nuclear immunoreactivity (+) was found in responder patients 1 and 2, whereas non-responder patients 3 and 4 showed SOX17 expression (−) in nuclei of tumor tissue. A 4-fold enlarged image of tumor area indicated by black box is shown in lower left inset for each patient (Original magnification: 100X). d IHC staining results showed higher SOX17 expression in CCRT responders than CCRT non-responders. The SOX17 IHC staining level is indicated in the Y-axis. One dots represented one patient slides. P values were calculated by 2-tailed t test and are shown as indicated. e Inverse correlation between DNA methylation and protein expression in SOX17. f ROC curve showing the performance of SOX17 protein expression in predicting the CCRT response, with the area under curve (AUC) being 0.664 and P values being 0.048