Variants in the CYP2B6 3′UTR Alter In Vitro and In Vivo CYP2B6 Activity: Potential Role of MicroRNAs

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

CYP2B6*6 and CYP2B6*18 are the most clinically important variants causing reduced CYP2B6 protein expression and activity. However, these variants do not account for all variability in CYP2B6 activity. Emerging evidence has shown that genetic variants in the 3'UTR may explain variable drug response by altering microRNA regulation. Five 3'UTR variants were associated with significantly altered efavirenz AUC0-48 (8-OH-EFV/EFV) ratios in healthy human volunteers. The rs70950385 (AG>CA) variant, predicted to create a microRNA binding site for miR-1275, was associated with a 33% decreased CYP2B6 activity among normal metabolizers (AG/AG vs. CA/CA (P < 0.05)). In vitro luciferase assays were used to confirm that the CA on the variant allele created a microRNA binding site causing an 11.3% decrease in activity compared to the AG allele when treated with miR-1275 (P = 0.0035). Our results show that a 3'UTR variant contributes to variability in CYP2B6 activity.

Related collections

Most cited references 23

Record: found
Abstract: found
Article: not found

MicroRNA-directed cleavage of HOXB8 mRNA.

Soraya Yekta, I-Hung Shih, David Bartel (2004)

MicroRNAs (miRNAs) are endogenous approximately 22-nucleotide RNAs, some of which are known to play important regulatory roles in animals by targeting the messages of protein-coding genes for translational repression. We find that miR-196, a miRNA encoded at three paralogous locations in the A, B, and C mammalian HOX clusters, has extensive, evolutionarily conserved complementarity to messages of HOXB8, HOXC8, and HOXD8. RNA fragments diagnostic of miR-196-directed cleavage of HOXB8 were detected in mouse embryos. Cell culture experiments demonstrated down-regulation of HOXB8, HOXC8, HOXD8, and HOXA7 and supported the cleavage mechanism for miR-196-directed repression of HOXB8. These results point to a miRNA-mediated mechanism for the posttranscriptional restriction of HOX gene expression during vertebrate development and demonstrate that metazoan miRNAs can repress expression of their natural targets through mRNA cleavage in addition to inhibiting productive translation.

0 comments Cited 442 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: found

Is Open Access

PolymiRTS Database 3.0: linking polymorphisms in microRNAs and their target sites with human diseases and biological pathways

Anindya Bhattacharya, Jesse D. Ziebarth, Yan-Yan Cui (2013)

Polymorphisms in microRNAs (miRNAs) and their target sites (PolymiRTS) are known to disrupt miRNA function, leading to the development of disease and variation in physiological and behavioral phenotypes. Here, we describe recent updates to the PolymiRTS database (http://compbio.uthsc.edu/miRSNP), an integrated platform for analyzing the functional impact of genetic polymorphisms in miRNA seed regions and miRNA target sites. Recent advances in genomic technologies have made it possible to identify miRNA–mRNA binding sites from direct mapping experiments such as CLASH (cross linking, ligation and sequencing of hybrids). We have integrated data from CLASH experiments in the PolymiRTS database to provide more complete and accurate miRNA–mRNA interactions. Other significant new features include (i) small insertions and deletions in miRNA seed regions and miRNA target sites, (ii) TargetScan context + score differences for assessing the impact of polymorphic miRNA–mRNA interactions and (iii) biological pathways. The browse and search pages of PolymiRTS allow users to explore the relations between the PolymiRTSs and gene expression traits, physiological and behavioral phenotypes, human diseases and biological pathways.

0 comments Cited 125 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Efavirenz plasma levels can predict treatment failure and central nervous system side effects in HIV-1-infected patients.

Catia Marzolini, Amalio Telenti, Laurent Decosterd … (2001)

Limited information exists on the clinical usefulness of drug level monitoring for efavirenz, a once-daily non-nucleoside reverse transcriptase inhibitor (NNRTI). The aim of this study was to determine whether efavirenz plasma concentration monitoring could predict treatment failure and central nervous system (CNS) tolerability. Blood samples were obtained from 130 HIV-infected patients receiving efavirenz in combination with other antiretroviral agents for more than 3 months. Efavirenz plasma concentrations were measured by high-performance liquid chromatography. An evaluation of CNS side-effects was performed and the viral load, CD4 cell count and other clinical and laboratory data were assessed. In 85 patients, these measures were repeated at 3 month intervals. Efavirenz plasma levels (n = 226) were measured at an average of 14 h after drug intake. Drug concentrations ranged from 125 to 15230 microg/l (median 2188). Large inter-patient (CV 118%) and limited intra-patient (CV 30%) variabilities were observed in efavirenz levels. Virological failure was observed in 50% of patients with low efavirenz levels ( 4000 microg/l) compared with patients with 1000-4000 microg/l. Treatment failure and CNS side-effects are associated with low and high efavirenz plasma levels, respectively. The important inter-individual variability in efavirenz levels strongly argues for dose adjustment on the basis of therapeutic drug monitoring to optimize treatment.