Vorce R L, Goodman J I
Biochem Biophys Res Commun. 1985 Jan 31;126(2):879-83. doi: 10.1016/0006-291x(85)90267-0.
The extent of methylation of a gene, i.e. percent of cytosine present as 5-methylcytosine, is correlated with its activity. Hypermethylation is associated with non-expression, whereas hypomethylation is a necessary but not sufficient condition for expression. In this study, the methylation state of the serum albumin gene as compared to the Kirsten-ras (Ki-ras) oncogene was assessed in hepatocytes and non-parenchymal cells (NPC) isolated from rat liver. The results of this investigation indicate that the serum albumin gene is hypomethylated in hepatocytes and hypermethylated in NPC. This is consistent with expression of the gene in the former cell type, and non-expression in the latter. In contrast, the Ki-ras oncogene is hypermethylated in both hepatocytes and NPC, suggesting that it is, at most, minimally expressed in normal rat liver.
一个基因的甲基化程度，即作为5-甲基胞嘧啶存在的胞嘧啶百分比，与其活性相关。高甲基化与不表达相关，而低甲基化是表达的必要但不充分条件。在本研究中，对从大鼠肝脏分离的肝细胞和非实质细胞（NPC）中血清白蛋白基因与 Kirsten-ras（Ki-ras）癌基因相比的甲基化状态进行了评估。该研究结果表明，血清白蛋白基因在肝细胞中低甲基化，而在NPC中高甲基化。这与该基因在前者细胞类型中的表达以及在后者中的不表达相一致。相反，Ki-ras癌基因在肝细胞和NPC中均高甲基化，表明它在正常大鼠肝脏中至多是最低限度地表达。
