CYP3A4 probably has the broadest catalytic activity of any cytochrome P450. It is a crucial task to test new drug candidates in a reliable system for their ability to induce expression of this enzyme. Firstly, a total of 300 bp core distal enhancer of CYP3A4 XREM region (-7972/-7673) were amplified from human genomic DNA. The PCR product was then ligated into a human secretory alkaline phosphat...

cyp3a4 probably has the broadest catalytic activity of any cytochrome p450. it is a crucial task to test new drug candidates in a reliable system for their ability to induce expression of this enzyme. firstly, a total of 300 bp core distal enhancer of cyp3a4 xrem region (-7972/-7673) were amplified from human genomic dna. the pcr product was then ligated into a human secretory alkaline phosphat...

CYP3A4 probably has the broadest catalytic activity of any cytochrome P450. It is a crucial task to test new drug candidates in a reliable system for their ability to induce expression of this enzyme. Firstly, a total of 300 bp core distal enhancer of CYP3A4 XREM region (-7972/-7673) were amplified from human genomic DNA. The PCR product was then ligated into a human secretory alkaline phosphat...

CYP3A4 is one of the major drug-metabolizing enzymes in human and is responsible for the metabolism of 60% of clinically used drugs. Many drugs are able to induce the expression of CYP3A4, which usually causes drug-drug interactions and adverse drug reactions. This study aims to explore the role of histone modifications in rifampicin-induced expression of CYP3A4 in LS174T cells. We found that t...

Two vital enzymes of the CYP3A subfamily, CYP3A4 and CYP3A5, are differentially expressed in the human lung. However, the molecular mechanisms that regulate tissue-selective expression of the genes are poorly understood. The ability of the 5' upstream promoter region of these two genes to drive luciferase reporter activities in human lung A549 cells was dramatically different. The CYP3A5 promot...

CYP3A4 (cytochrome P450 3A4) is involved in the metabolism of more than 50% of drugs and other xenobiotics. The expression of CYP3A4 is induced by many structurally dissimilar compounds. The PXR (pregnane X receptor) is recognized as a key regulator for the induction, and the PXR-directed transactivation of the CYP3A4 gene is achieved through a co-ordinated mechanism of the distal module with t...

Farnesoid X receptor (FXR) functions as a regulator of bile acid and lipid homeostasis and is recognized as a promising therapeutic target for metabolic diseases. The biologic function of FXR is mediated in part by a small heterodimer partner (SHP); ligandactivated FXR enhances SHP expression, and SHP in turn represses the activity of multiple transcription factors. This study aimed to investig...

CYP3A4, the predominant cytochrome P450 (P450) expressed in human liver and intestine, contributes to the metabolism of approximately half the drugs in clinical use today. CYP3A4 catalyzes the 6beta-hydroxylation of a number of steroid hormones and is involved in the bioactivation of environmental procarcinogens. The expression of CYP3A4 is affected by several stimuli, including environmental f...

Pregnane X receptor (PXR) has been reported to regulate the expression of drug-metabolizing enzymes, such as the cytochrome P450 3A (CYP3A) family and transporters, such as multiple drug resistance 1 (MDR1). Fucoxanthin, the major carotenoid in brown sea algae, is a putative chemopreventive agent. In this study, we determined whether fucoxanthin could overcome drug resistance through attenuatio...

Despite the established interindividual variability and ontogeny of the CYP3A enzymes, the most abundant phase I drug-metabolizing enzymes in human liver and intestine, the mechanisms that regulate basal expression remain poorly understood. Electrophoretic mobility shift assays using nuclear proteins extracted from human prenatal and postnatal liver samples identified multiple, developmentally ...