Cytochrome P450-1A1 (CYP1A1) is an extrahepatic phase I metabolizing enzyme whose expression is suppressed under physiologic conditions but can be induced by substrates via the aryl hydrocarbon receptor (AhR). Recent studies have shown that the majority of breast cancer tumors constitutively express CYP1A1. These findings led us to test the hypothesis that CYP1A1 promotes breast cancer progress...

Cytochrome P450 1A1 (CYP1A1) is a member of the cytochrome p450 enzyme family, which is involved in the metabolisms of carcinogenic metabolites, such as benzo(a) pyrene. In this study, we identified miR-892a as a negative regulator of CYP1A1 expression. Luciferase assays revealed a sequence in the 3'-untranslated region of CYP1A1 that displayed a perfect match with miR-892a, and revealed that t...

Regulation of the CYP1A1 gene has been shown to involve the aryl hydrocarbon receptor and the CYP1A1 gene expression is induced by AhR ligands. Primaquine is an antimalarial agent that does not exhibit the structural properties of a classical AhR ligand. We have evaluated the mechanisms by which this compound induces CYP1A1 expression using rat hepatoma H4IIE cells and V79 cells stably expressi...

The present study examined modifications of β-naphthoflavone (β-NF)-induced cytochrome P450 1A1 (CYP1A1) expression by flavonoids in mouse hepatocytes in primary culture. Some flavonoids (apigenin, chrysin, flavone, flavanone, galangin, luteolin, and naringenin) by themselves induced CYP1A1 mRNA expression, especially flavone which was even more effective than β-NF. The effect on β-NF-induced C...

Cytochrome P450-1A1 (CYP1A1) is an extrahepatic phase I metabolizing enzyme whose expression is suppressed under physiologic conditions but can be induced by substrates via the aryl hydrocarbon receptor (AhR). Recent studies have shown that the majority of breast cancer tumors constitutively express CYP1A1. These findings led us to test the hypothesis that CYP1A1 promotes breast cancer progress...

Recent studies have examined the relationship between genetic polymorphisms of the human cytochrome P-4501A1 (CYP1A1) gene and lung cancer susceptibility. We have quantified genotypic frequencies and measured gene expression in the CYP1A1 gene within racially diverse groups in order to determine the relationship between genotype and transcriptional regulation of the CYP1A1 gene. Lymphocytes wer...

Cytochrome CYP1A1 gene expression, induced by polycyclic aromatic hydrocarbons and dioxins, eg. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is regulated mainly at the level of transcription. Inducible activation of the CYP1A1 promotor is mediated by a ligand-dependent transcription factor dimer complex including the aryl hydrocarbon receptor (AHR) and the AHR nuclear translocator (ARNT) protein...

Cytochrome P450 1A1 (CYP1A1) is induced by exposure to polycyclic aromatic hydrocarbons (PAHs) and planar halogenated aromatic hydrocarbons (PHAHs) such as non-ortho polychlorinated biphenyls (PCBs). In this study, we examined CYP1A1 protein expression immunohistochemically in multiple organs of beluga whales from two locations in the Arctic and from the St. Lawrence estuary. These beluga popul...

Cytochrome P4501A1 (CYP1A1) has been implicated in the conversion of numerous polycyclic aromatic hydrocarbons into electrophilic species capable of binding covalently to DNA and has therefore been postulated to be involved in the initiation of carcinogenesis. The expression of CYP1A1 protein appears not to be constitutive, but is readily inducible by aryl hydrocarbon (Ah) receptor ligands in a...

The human CYP1A1 gene is regulated by the aryl hydrocarbon receptor (AhR), and induction of CYP1A1 is known to play an important role in xenobiotic metabolism. To examine the regulation of human CYP1A1 in vivo, we created a transgenic mouse strain (Tg-CYP1A1(GFP)) expressing a chimeric gene consisting of the entire human CYP1A1 gene (15 kb) fused with a GFP reporter gene. The treatment of Tg-CY...