Cited by 258Pharmacogenetics and Drug MetabolismDrug Transport and Resistance MechanismsDrug-Induced Hepatotoxicity and Protection

Comparative analysis of CYP3A expression in human liver suggests only a minor role for CYP3A5 in drug metabolism

Westlind-Johnsson, Anna, Malmebo, Sarah, Johansson, Anna, Otter, Charlotta, Andersson, Tommy B., Johansson, Inger, Edwards, Robert J., Boobis, Alan R. +1 more·2003·Drug Metabolism and Disposition

Abstract

To study mechanisms behind the interindividual variability in CYP3A expression and the relative contribution of the different CYP3A enzymes to the overall CYP3A activity, we have analyzed CYP3A4, CYP3A5, CYP3A43, and PXR mRNA and CYP3A4 and CYP3A5 protein expression, catalytic activity, and polymorphism in the CYP3A5 gene in a panel of 46 Caucasian human livers. Protein quantification was performed by Western blotting using enzyme-specific antibodies directed to the C termini of CYP3A4 or CYP3A5, and carrier protein-coupled peptides as standards. The mRNA levels were determined by quantitative real-time PCR. CYP3A activity was measured by analysis of the rate of testosterone 6beta-hydroxylation. A correlation existed between all CYP3A and PXR mRNA transcripts measured. The interindividual variability in CYP3A4 and CYP3A5 mRNA expression was higher than that of CYP3A protein and activity. The CYP3A5 protein was expressed at quantifiable levels in 5 (10.9%) of the livers. Four of those were heterozygous for the CYP3A5*1 allele and had CYP3A5 protein at a mean level of 17% of that of total CYP3A, whereas one liver sample was from a CYP3A5*3 homozygote individual having lower amounts of CYP3A5. In total, CYP3A5 only contributed 2% of the overall CYP3A protein among all samples. In conclusion, our data indicate that CYP3A4, CYP3A5, CYP3A43, and PXR hepatic mRNA expression correlate, indicating common regulatory features, and that the contribution of CYP3A5 to hepatic drug metabolism in Caucasians is insignificant.

Integrity signals

Registry

Crossref · 10.1124/dmd.31.6.755

Cites

38 of 38 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Cites

Flagged first, then by citations

1 of the 39 references couldn’t be matched to a known paper.

Cited by

Sorted by citations

Authors
Westlind-Johnsson, A., Malmebo, S., Johansson, A., Otter, C., Andersson, T. B., Johansson, I., Edwards, R. J., Boobis, A. R., & Ingelman-Sundberg, M.
Affiliations
Karolinska Institutet (SE)
Venue
Drug Metabolism and Disposition
Publisher
Elsevier BV
Published
2003-06
Volume
31
Issue
6
Pages
755-761
ISSN
0090-9556 (ISSN-L)
OpenAlex
W2126772533
Cited by
258
References
39
Citations by year
2026: 2 · 2025: 7 · 2024: 7 · 2023: 3 · 2022: 6 · 2021: 5 · 2020: 5 · 2019: 13 · 2018: 6 · 2017: 6 · 2016: 8 · 2015: 3 · 2014: 9 · 2013: 23 · 2012: 8
FWCI
22.15
Type
journal article
Language
en
Open access
closed
Locations
  • Drug Metabolism and Disposition (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmacogenetics and Drug Metabolism
  • Health Sciences › Medicine › Oncology › Drug Transport and Resistance Mechanisms
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Drug-Induced Hepatotoxicity and Protection
Keywords
CYP3A4, CYP3A5, CYP3A43, pregnane X receptor, interindividual variability, drug metabolism, testosterone 6beta-hydroxylation, CYP3A5*3 allele, hepatic mRNA expression, human liver
MeSH terms
Pregnane X Receptor, Alleles, Aryl Hydrocarbon Hydroxylases, Cytochrome P-450 Enzyme System, Genotype, Humans, Hydroxylation, Microsomes, Liver, Polymorphism, Genetic, Receptors, Steroid, RNA, Messenger, Testosterone, Blotting, Western, Gene Expression, Polymerase Chain Reaction, Receptors, Cytoplasmic and Nuclear, White People, Cytochrome P-450 CYP3A

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review