Melina Christou

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The levels of expression of cytochromes P-450b and P-450e (both inducible by phenobarbital (PB) and differing by only 14 of 491 amino acids) in liver microsomes from untreated male rats were separately quantitated by Western blotting with a polyclonal antibody raised against P-450b that is equally effective against P-450e (anti P-450b/e). A protein with(More)
A novel benz[a]anthracene and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible cytochrome P-450 (P450EF), which is very active in polycyclic aromatic hydrocarbon metabolism, has been purified from C3H10T1/2 mouse embryo fibroblasts (Pottenger, L. H., Christou, M., and Jefcoate, C. R. (1991) Arch. Biochem. Biophys. 286, 488-497). P450EF was shown to be(More)
Rates of microsomal 17 beta-estradiol (E2) hydroxylation at the C-2, -4, -6 alpha, and -15 alpha positions are each induced greater than 10-fold by treating MCF-7 breast cancer cells with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The TCDD-induced activities at the C-2, -6 alpha and -15 alpha positions have been attributed to cytochrome P450 1A1 (CYP1A1);(More)
Cultured human mammary carcinoma (MCF-7) cells exhibited constitutive cytochrome P450-dependent metabolism of 7,12-dimethylbenz[a]anthracene (DMBA) (45-75 pmol/mg microsomal protein). Exposure of the cells to 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD), which is known to induce CYP1A1, not only resulted in a 30-fold increase in the total microsomal(More)
Cultured rat mammary cells express both CYP1A1 and CYP1B1 in response to polycyclic aromatic hydrocarbons (PAH) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in a cell type-specific manner. The expression of each P450 was determined functionally (regioselective PAH metabolism), as apoprotein (immunoblots) and as mRNA (Northern hybridization). The(More)
We have previously demonstrated the anticarcinogenic effects of monocyclic monoterpenes such as limonene when given during the initiation phase of 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary cancer in Wistar-Furth (WF) rats. Here we investigated the possible mechanisms for this chemoprevention activity including limonene's effects on DMBA-DNA(More)
Hypoxic-ischaemic encephalopathy is a leading cause of child death, with high mortality and morbidity, including cerebral palsy, epilepsy and cognitive disabilities. Hypoxia-ischaemia (HI) strongly up-regulates Signal Transducer and Activator of Transcription 3 (STAT3) in the immature brain. Our aim was to establish whether STAT3 up-regulation is associated(More)
Stromal cells from mouse endometrium, E041 cells, at passages 21, 23 and 26 were metabolically active towards 7,12-dimethylbenz[a]anthracene (DMBA). The total DMBA-metabolizing activity of E041 cells was preferentially increased by benz[a]anthracene (BA) relative to 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) treatment (7-fold by BA and 4-fold by TCDD), but(More)
The major polycyclic aromatic hydrocarbon-metabolizing cytochrome P450 in the mouse embryo fibroblast-derived C3H/10T1/2 CL8 cell line (P450-EF) has been partially purified from benz[a]anthracene (BA)-induced 10T1/2 cells (40 pmol P450/mg). The purification of P450-EF was carried out by sequential chromatography of solubilized microsomes over hydrophobic(More)
Seven different forms of cytochrome P-450 have been purified from rat liver microsomes. The major 3-methylcholanthrene (MC) inducible cytochrome P-450 (form c) exhibits the greatest activity toward both benzo[a]pyrene (BP) (58 min-1) and 7,12-dimethylbenz[a]anthracene (DMBA) (29 min-1) and forms substantially high spin, high affinity complexes (Kd = 10 nM)(More)