Cytochrome P450 CYP1B1 is a recently cloned dioxin-inducible form of the cytochrome P450 family of xenobiotic metabolizing en zymes. An antibody raised against a peptide specific for CYP1B1 was found to recognize CYP1B1 expressed in human lymphoblastoid cells but not to recognize other forms of cytochrome P450, particularly CYP1A1 and CYP1A2. Using this antibody, the cellular distribution and l...

Cytochrome P450 1B1 (CYP1B1) and catechol-O-methyltransferase (COMT) enzymes play critical roles in estrogen metabolism. Alterations in the catalytic activity of CYP1B1 and COMT enzymes have been found associated with altered breast cancer risk in postmenopausal women in many populations. The substitution of leucine (Leu) to valine (Val) at codon 432 increases the catalytic activity of CYP1B1, ...

Estrogen unopposed by progestins is a key factor in endometrial cancer etiology. Cytochrome P450 1B1 (CYP1B1), responsible for the 4-hydroxylation of estrogen, may be important in endometrial carcinogenesis, either as a regulator of estrogen availability or as a producer of potentially genotoxic estrogen metabolites. We investigated the association of CYP1B1 genotype and endometrial cancer risk...

The cytochrome P450 family of enzymes is involved in the Phase I metabolism of a wide variety of compounds. Although generally involved with detoxification, overexpression of one family member, cytochrome P450 1B1 (CYP1B1), has been associated with human epithelial tumors. As such, CYP1B1 was hypothesized to be a novel target for the development of anticancer therapies. We investigated expressi...

AIMS Pulmonary arterial hypertension (PAH) occurs more frequently in women than men. Oestrogen and the oestrogen-metabolising enzyme cytochrome P450 1B1 (CYP1B1) play a role in the development of PAH. Anorectic drugs such as dexfenfluramine (Dfen) have been associated with the development of PAH. Dfen mediates PAH via a serotonergic mechanism and we have shown serotonin to up-regulate expressio...

PURPOSE CYP1B1 mutations cause autosomal recessive congenital glaucoma. Disease risk assessment for families with CYP1B1 mutations requires knowledge of the population mutation carrier frequency. The purpose of this study is to determine the CYP1B1 mutation carrier frequency in clinically normal individuals residing in the United States. Because CYP1B1 mutations can exhibit variable expressivit...

The cytochrome P450 1B1 (CYP1B1) is a heme-thiolate monooxygenase involved in both estrogen biosynthesis and metabolism. For instance, CYP1B1 catalyzes the hydroxylation of E2 leading to the production of 4-hydroxyestradiol that may act as a potent carcinogenic agent. In addition, CYP1B1 is overexpressed in different tumors including breast cancer. In this scenario, it is worth mentioning that ...

CYP1A1 and CYP1A2 exhibit catalytic activity predominantly for the 2-hydroxylation of estradiol, whereas CYP1B1 exhibits catalytic activity predominantly for 4-hydroxylation of estradiol. To understand why CYP1B1 predominantly hydroxylates the 4-position of estradiol, we constructed three-dimensional structures of CYP1A1 and CYP1B1 by homology modeling, using the crystal structure of CYP1A2, an...

Human cytochrome P450 (CYP) 1B1 is a key enzyme in the metabolism of 17beta-estradiol (E2). CYP1B1 is mainly expressed in endocrine-regulated tissues, such as mammary, uterus, and ovary. Because many CYP enzymes are likely to be induced by the substrates themselves, we examined whether the human CYP1B1 expression is regulated by E2 in the present study. Real-time reverse transcription-PCR analy...