Fig. 2
Expression and methylation status of ZNF331 in primary CRC. a Representative results of MSP for ZNF331 in primary CRC samples and matched adjacent tissue samples. N normal colorectal mucosa. b, c Kaplan–Meier curves show the association between ZNF331 methylation and OS and DFS in CRC patients. Blue: ZNF331 unmethylated CRC patients (n = 48); red: ZNF331 methylated CRC patients (n = 98) (p = 0.001, p = 0.024, log-rank test). d Representative IHC results show the expression of ZNF331 in CRC samples and matched adjacent tissue samples (upper, ×100; lower, ×400). e ZNF331 expression scores are shown as box plots, and the horizontal lines represent the median score; the bottom and top of the boxes represent the 25th and 75th percentiles, respectively; vertical bars represent the range of data (**p < 0.01). f The bar diagram shows the expression and DNA methylation status of ZNF331 in different cancer samples. Reduced expression of ZNF331 was significantly associated with promoter region methylation (**p < 0.01). g TCGA data and GTEx data show ZNF331 mRNA expression levels in CRC tissues (n = 383) and normal colorectal mucosa (n = 359) according to RNA-seq results. Box plots: the levels of ZNF331 expression. Horizontal lines: counts of log2 (TPM + 1). TPM Transcripts Per Million (reads) (***p < 0.001). h Methylation status of 14 CpG sites in promoter region of human primary CRC tissue samples (T, shown in red) (n = 356) compared to adjacent normal colorectal tissues (A, shown in green) (n = 21) (***p < 0.001). i The correlation between expression level of ZNF331 and methylation status of CpG sites in the vicinity of the TSS. j Methylation status of top three CpG sites in promoter region (shown in red in i) are correlated with loss of/reduced ZNF331 expression in 356 cases of CRC (all p < 0.0001)