Figure 3

Cumulative promoter hypermethylation of WIF1, PENK, and NPY in adjacent normal and colorectal carcinoma tissues. A, cumulative methylation levels in tumor tissues and homologous adjacent normal tissues in an independent experiment, paired samples (n = 15) of adjacent normal and tumor tissue were quantified by using QM-MSP. Samples were scored for cumulative methylation index (CMI) of three genes. Results are plotted as stacked bar graphs. Differences of CMI between homologous adjacent normal tissues (Norm) versus tumor tissues (Tumor) were significant (P < 0.0001, Student-test). Plotted is the mean (± SD; bars) amount of CMI in Norm (mean = 15.07 ± 16.60) and in Tumor tissues (mean = 190.57 ± 77.65). Actual percentage of methylation values are listed in the table for tumor (T), adjacent normal (N), and control (Ctrl). B, Cumulative methylation of target genes by QM-MSP of DNA tissue samples from CRC patients. Mean cumulative methylation in stage I / II and in stage III / IV are shown. Differences between tumor stages were not significant (P > 0.09, Student-test). Plotted is the mean (± SD; bars) amount of cumulative methylation in Stages I / II (mean = 156.74 ± 83.96) versus Stages III / IV (mean = 213.14 ± 68.66).