Open AccessIn vitro analysis of factors influencing CYP 1A2 expression as potential determinants of interindividual variation
Author(s) -
Xie ChengHui,
Pogribna Marta,
Word Beverly,
LynCook Lascelles,
LynCook Beverly D.,
Hammons George J.
Publication year - 2017
Publication title -
pharmacology research and perspectives
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.975
H-Index - 27
ISSN - 2052-1707
DOI - 10.1002/prp2.299
Subject(s) - cyp1a2 , cyp2a6 , gene expression , biology , tobacco smoke , nicotine , chemistry , pharmacology , metabolism , cytochrome p450 , biochemistry , gene , neuroscience , polymer chemistry
Abstract Individual differences in drug metabolism contribute to interindividual variation that characterizes responses to drugs and risk in exposure to foreign chemicals. Large individual differences are found in expression levels of CYP 1A2 , a major drug‐metabolizing enzyme. Underlying causes for this variation are not well understood. Several factors, including tobacco smoking, consumption of cruciferous vegetables, and sex, have been associated with modulating CYP 1A2 expression. To understand factors regulating expression of CYP 1A2 in establishing a causal relationship, this study examined effects of cigarette smoke condensate ( CSC ), indole‐3‐carbinol (I3C), and 17 β ‐estradiol (estradiol) on CYP 1A2 expression in in vitro systems using human liver and lung cells. Treatment with CSC (2–25 μ g/mL) significantly increased levels of CYP 1A2 in six cell lines examined, in a concentration‐ and time‐dependent manner. Fold changes in expression levels relative to controls varied among cell lines. CYP 1A2 enzymatic activity also increased with CSC exposure. Treatment of H1299 and HepB3 cells with dietary agent I3C (50 and 100 μ mol/L) increased CYP 1A2 expression. In human cell lines H1299 and H1395, treatment with estradiol (10 and 100 nmol/L) significantly reduced expression of CYP 1A2 . Using Ch IP assays, effects of CSC on histone modifications were analyzed. Increases in H3K4me3 and H4K16ac were observed at several segments in the CYP 1A2 gene, whereas H3K27me3 decreased, following CSC treatment. These results suggest that CYP 1A2 expression is affected epigenetically by CSC . Additional studies will be needed to further establish regulatory mechanisms underlying effects of various environmental, dietary, and endogenous factors on CYP 1A2 expression in better predicting individual variation.