Identification and characterization of novel alternative splice variants of human constitutive androstane receptor in liver samples of Koreans and Caucasians.

Human constitutive androstane receptor (hCAR, NR1I3) is a member of the orphan nuclear receptor family and regulates the transcription of many drug-metabolizing enzymes and drug transporters. Previous studies have shown that the hCAR gene produces a number of different kinds of mRNA splicing variants (SVs) in non-Asian ethnicities. In the present study, we identified 18 hCAR SVs (SV1-SV18), including four novel SVs in Korean human livers.

Capsaicin induces CYP3A4 expression via pregnane X receptor and CCAAT/enhancer-binding protein β activation.

Scope: Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is the principal pungent ingredient in hot red and chili peppers. Many studies have focused on the anticarcinogenic or chemopreventive activities of capsaicin. However, the influence of capsaicin on CYP3A4, its involvement in drug metabolism, and the underlying mechanisms remain unclear.

A haplotype of CYP2C9 associated with warfarin sensitivity in mechanical heart valve replacement patients.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT * CYP2C9 single nucleotide polymorphisms (SNPs) are important in safe and effective oral anticoagulation with warfarin use. * Although CYP2C9*2 and *3 are important genetic factors for the warfarin dose, one of the CYP2C9 SNPs, IVS-65G>C, has been suggested to be associated with warfarin sensitivity. However, as of yet, there has been no explanation about the possible mechanism and linkage analysis.

Effect of CYP2C9 and VKORC1 genotypes on early-phase and steady-state warfarin dosing in Korean patients with mechanical heart valve replacement.

Objectives: The effect of CYP2C9 and vitamin K epoxide reductase complex subunit 1 (VKORC1) genotypes was evaluated for the early-phase and steady-state warfarin dosing in Korean patients with mechanical heart valve replacement.

Methods: The genotypes of CYP2C9 variants including CYP2C9*3, CYP2C9*13, and CYP2C9*14, and VKORC1 1173C>T were assessed for the association with warfarin dosing in 265 patients whose data were collected for warfarin dose; international normalized ratio (INR), comedication, comorbidity, and other clinical characteristics.

Results: In the early phase of warfarin therapy, the combined genotypes of CYP2C9 and VKORC1 caused statistically significant difference in warfarin dose from day 7 of warfarin dosing and the subsequent time course of dose increase showed significant difference among the three different genotypes (P<0.

Duplex pyrosequencing of the TPMT*3C and TPMT*6 alleles in Korean and Vietnamese populations.

Background: Thiopurine S-methyltransferase (TPMT) genetic polymorphisms have been studied intensively in relation to thiopurine toxicity. In the present study, an improved pyrosequencing method was developed for TPMT genotyping and used to investigate the genotype frequency in Korean and Vietnamese populations.

Methods: Four-hundred Korean and 159 Vietnamese subjects were genotyped by pyrosequencing for TPMT 238G>C, 460G>A, 539A>T, and 719A>G variants, in order to determine the TPMT*2, *3A, *3B, *3C, and *6 alleles.

CYP2S1 gene polymorphisms in a Korean population.

Cytochrome P450 2S1 (CYP2S1) is a drug-metabolizing enzyme that shows interindividual variations in response to treatments for psoriasis and is regarded as a putative prognostic marker for colorectal cancer treatment. To gain insight into the genetic basis for the interindividual variations, CYP2S1 gene polymorphisms were analyzed in Korean subjects. Using direct sequencing of the CYP2S1 gene, 12 genetic variations, which included the two novel nonsynonymous mutations CYP2S1 S61N (0.