Epigenetic analysis of MUC1 expression in human colonic normal and neoplastic crypts. (A) Expression of MUC1 mRNA examined by quantitative real time RT-PCR. The bar graphs show gene expression levels relative to those in Panc1 cells. (B) DNA methylation of the MUC1 promoter region examined by MSE in Caco2 cells (high methylation control) and LS174T cells (low methylation control). (C). Expression of MUC1 protein examined by immunohistochemical staining. N: normal tissue. T: tumor tissue. All isolated crypt samples showed high expression levels of MUC1 mRNA and protein, and hypomethylation of the promoter region.