Methylation of the KEAP1 promoter in CRC tissue samples. (A) MSP for the KEAP1 promoter was performed using bisulfite-modified DNA from 40 CRC tissues and adjacent normal colorectal tissues. MSP results from 10 patients are shown. M: MSP of methylation-specific primers; U: MSP of non-methylation-specific primers; P: positive methylated DNA control; N: negative unmethylated DNA control. (B) Representative results of MSP sequence analysis of tumor tissues. The methylation status of the KEAP1 promoter region in patient tumor tissues was determined using methylation-specific primers (upper), and non-methylation-specific primers (lower). Methylation is indicated in red. (C) Expression and subcellular localization of Nrf2. Nrf2 was more highly expressed in HT29 cells (a) and a methylated tissue sample (c) compared with Colo320 cells (b) and a non-methylated tissue sample (d). Expression and localization of Nrf2 was studied using an anti-human Nrf2 antibody.