DNA methylation determines the regulation of pregnane X receptor on CYP3A4 expression.

The expression and activity of CYP3A4 vary among individuals. With the development of epigenetics, it is now possible to elucidate interindividual differences in drug-metabolizing enzymes. Here, we aimed to explore the potential relationship between DNA methylation and CYP3A4 expression.

Effects of UGT1A1*6, UGT1A1*28, and ABCB1-3435C>T polymorphisms on irinotecan induced toxicity in Chinese cancer patients.

Object: The aim of this study was to investigate whether UGT1A1*6/*28 or ABCB1-3435C>T polymorphisms affect irinotecan-induced severe diarrhea and neutropenia in Chinese cancer patients.

Methods: A total of 157 cancer patients was enrolled in this study and the genotypes of UGT1A1*6/*28 and ABCB1-3435C>T polymorphisms were analyzed by PCRSanger sequence. The relationship between UGT1A1*6/*28 and ABCB1-3435C>T polymorphisms and irinotecan induced severe diarrhea and neutropenia were analyzed.

Effect of CYP3A4*1G, CYP3A5*3, POR*28, and ABCB1 C3435T on the pharmacokinetics of nifedipine in healthy Chinese volunteers.

Objective: Nifedipine is a calcium channel blocker that is widely used in the treatment of cardiovascular disease. However, significant individual variances in the disposition of nifedipine have been reported, and genetic factors are considered to play an important role. The aim of the present study was to investigate the effect of CYP3A4*1G, CYP3A5*3, ABCB1-C3435T, and POR*28 genetic polymorphisms on nifedipine pharmacokinetics in healthy Chinese volunteers.