In contrast to most human malignancies, epidemiologic studies have frequently reported a reduced risk of differentiated thyroid cancer in tobacco consumers. Cytochrome P4501A1 (CYP1A1) gene variants may be related to an increased capacity to activate polycyclic aromatic hydrocarbons, producing highly reactive electrophilic intermediates that might damage DNA. Hence, the germline inheritance of ...

There is concern that exposures to the environmental chemicals polychlorinated biphenyls (PCBs) may contribute to breast cancer risk. An individual's susceptibility to the effects of PCBs may be partially determined by polymorphisms in the gene encoding the biotransformation enzyme cytochrome P450 1A1 (CYP1A1). PCB exposure induces CYP1A1 activity, and PCBs themselves or other xenobiotics can b...

background: age-related differences in the ethoxyresorufin o-deethylase (erod) activity of cyp1a1 and its inducibility in rats may determine the toxic potential of acetaminophen.  this study was carried out to compare the effects of acetaminophen (apap) and β-naphthoflavone (βnf) on cyp1a1 activity in young and adult rats. methods: for this purpose, young and adult rats (n = four / group) were...

Prenatal exposures to polycyclic aromatic hydrocarbons (PAHs) are associated with adverse outcomes including small for gestational age infants. We have previously reported differential levels of PAHs in the placenta preterm delivery. found that a specific PAH, dibenzoanthracene (DBA), was significantly higher than either benzo[a]pyrene (BaP) or Benzo[b]fluoranthene (BbF). Furthermore, we placen...

Crossing the Cyp1a1/1a2(-/-) double-knockout mouse with the Cyp1b1(-/-) single-knockout mouse, we generated the Cyp1a1/1a2/1b1(-/-) triple-knockout mouse. In this triple-knockout mouse, statistically significant phenotypes (with incomplete penetrance) included slower weight gain and greater risk of embryolethality before gestational day 11, hydrocephalus, hermaphroditism, and cystic ovaries. Or...

Aims: This study examined whether genetic polymorphisms of tobacco and alcohol-related metabolic genes such as GSTM1, GSTT1, GSTP1, CYP1A1, CYP2E1 and DNA repair genes (XRCC1 194Trp, XRCC1 399Gln, and XRCC3 Met) contribute to the risk of developing OSCC. Methods: Patients eligible for inclusion were over 18 years, had pathologically confirmed OSCC and were followed prospectively for at least tw...

The cytochrome P450 (CYP1A1) enzyme metabolically activates many polycyclic aromatic hydrocarbons, including benzo[a]pyrene (BaP), to DNA- and protein-binding intermediates that are associated with toxicity, mutagenesis, and carcinogenesis. As a result, it is widely accepted that CYP1A1 potentiates the toxicity of this class of chemicals. In distinct contrast, we show here that CYP1A1 inducibil...