Dawson J R, Adams D J, Wolf C R
FEBS Lett. 1985 Apr 22;183(2):219-22. doi: 10.1016/0014-5793(85)80780-8.
Human cytochrome P-450, UDP-glucuronosyltransferase and sulphotransferase activities have been measured in the cell line Hep G2 following treatment of cells with 3-methylcholanthrene or phenobarbital. 3-Methylcholanthrene treatment caused a 20-30-fold increase in the O-deethylation of 7-ethoxycoumarin. The glucuronidation and sulphation of the product 7-hydroxycoumarin were increased 36 and 7 fold, respectively. In comparison, phenobarbital treatment did not increase these activities significantly. However, phenobarbital-inducible proteins were identified on "Western blots' using antibodies to a rat liver phenobarbital inducible P-450 form. The molecular masses of the proteins did not coincide with those expected for cytochromes P-450. However, characteristic of P-450 forms, the synthesis of these proteins was suppressed by 3-methylcholanthrene treatment. The Hep G2 cell line represents a potentially useful model for studying the regulation of human P-450 genes.
在用3-甲基胆蒽或苯巴比妥处理细胞后，已在Hep G2细胞系中测定了人细胞色素P-450、UDP-葡糖醛酸基转移酶和磺基转移酶的活性。3-甲基胆蒽处理使7-乙氧基香豆素的O-脱乙基作用增加了20至30倍。产物7-羟基香豆素的葡糖醛酸化和硫酸化分别增加了36倍和7倍。相比之下，苯巴比妥处理并未显著增加这些活性。然而，使用针对大鼠肝苯巴比妥诱导型P-450形式的抗体，在“蛋白质免疫印迹”上鉴定出了苯巴比妥诱导型蛋白。这些蛋白的分子量与细胞色素P-450预期的分子量不一致。然而，作为P-450形式的特征，这些蛋白的合成受到3-甲基胆蒽处理的抑制。Hep G2细胞系是研究人P-450基因调控的一个潜在有用模型。
