A thorough DNA sequence analysis reveals that the mouse Cyp1a1 and Cyp1a2 loci are located with coding directions opposite to each other. The two genes are separated by approximately 13.9 kb of genomic DNA containing no open reading frames (mCyp1a1_1a2 junction). Within the mCyp1a1_1a2 junction, eight consensus dioxin responsive elements (DREs) are present and seven of the eight DREs located le...

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) carcinogenesis is initiated by N(2)-hydroxylation, mediated by several cytochromes P450, including CYP1A1. However, the role of CYP1A1 in PhIP metabolic activation in vivo is unclear. In this study, Cyp1a1-null and wild-type (WT) mice were used to investigate the potential role of CYP1A1 in PhIP metabolic activation in vivo. PhIP N(2)-hydro...

AIMS CYP1A1 and CYP1B1, members of the cytochrome P450 protein family, are regulated by fluid shear stress. This study describes the effects of duration, magnitude and pattern of shear stress on CYP1A1 and CYP1B1 expressions in human endothelial cells, towards the goal of understanding the role(s) of these genes in pro-atherogenic or anti-atherogenic endothelial cell functions. METHODS AND RE...

There are numerous conflicting epidemiological studies addressing correlations between cytochrome P450 1A1 (CYP1A1) genetic polymorphisms and lung cancer susceptibility, with associations plausibly linked to alterations in carcinogen bioactivation. Similarly, correlations between aryl hydrocarbon receptor gene (AHR) codon 554 genotype and CYP1A1 inducibility are controversial. The objective of ...

BACKGROUND A thymine/cytosine point mutation in the MSP I restriction site of cytochrome P450 1A1 (CYP1A1) has been linked to susceptibility to smoking-related cancers and is reported to result in increased enzyme activity. Therefore, we sought to determine whether allelic variation of CYP1A1 is associated with protein expression and protein activity in pterygium. METHODS We collected 150 pte...

The cytochrome P4501A1 (CYP1A1) enzyme is regulated at the transcriptional level and its expression is influenced by genetic factors, polymorphisms in the structural and regulatory genes, and by environmental factors such as exposure to polycyclic aromatic hydrocarbons (PAHs). To investigate the role of CYP1A1 in breast cancer, we studied CYP1A1 expression in breast tissue, thereby taking all p...

Many enzymes involved in xenobiotic metabolism, including cytochrome P450 (CYP) 1A1, are regulated by the aryl hydrocarbon receptor (AhR). 3,3',4,4',5-Penta chlorobiphenyl (PCB 126) is a potent ligand for AhR and can thus induce the expression of CYP1A1. Interestingly, we observed that human carcinoma cell lines derived from different types of epithelial cells displayed divergent degrees of CYP...

We conducted a meta-analysis to investigate the association of 2 single nucleotide polymorphisms in the cytochrome P450, family 1, subfamily 1A1 gene (CYP1A1), CYP1A1*2A and CYP1A1*2C, with the risk of developing different subtypes of leukemia in adults and children. A total of 26 studies published between 1999 and 2011 were identified by searching the PubMed, EMBASE, Medline, and Web of Scienc...

We recently demonstrated that heavy metals, Hg2+, Pb2+, and Cu2+ induced Cyp1a1 gene expression, yet the mechanisms involved remain unknown. To explore the molecular mechanisms involved in the modulation of Cyp1a1 by heavy metals, Hepa 1c1c7 cells were treated with the metals in the presence and absence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent Cyp1a1 inducer. Time-dependent effec...

The dioxin 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) induces phase I and II xenobiotic metabolizing enzymes (XME) which act sequentially to eliminate different classes of xenobiotics. The transcriptional effects of TCDD are generally mediated by the arylhydrocarbon receptor (AhR). We hypothesized that TCDD could also act indirectly, by increasing the activity of cytochrome P450 1A1 (CYP1A1)...