TISSUE-SPECIFIC EXPRESSION AND METHYLATION OF THE HUMAN CYP2E1 GENE

The level and number of CYP2E1 gene transcripts were investigated by n orthern blot analysis in various human adult tissues including liver, lung, placenta, skin and neurinoma. Three transcripts of 1.8, 2.6 and 4 Kb were expressed in a tissue-specific manner. The origin of the var ious transcripts was studied and showed that both 4 and 2.6 Kb mRNAs c ontained sequences from the 3' non-translated region of the gene and t hat the 4 Kb also contained region localized in the 5' non-translated region. Furthermore, it clearly appeared that a catalytically active C YP2E1 enzyme (as proved by NDMA demethylase activity) was only detecte d in tissues expressing the 1.8 Kb. The human CYP2E1 was also identifi ed through immunohistochemical techniques. Finally, we observed a rela tion between the hypomethylation of the human CYP2E1 gene and the hypo expression of the corresponding protein.