Abstract

P450 1B1, which preferentially forms carcinogenic metabolites from PAHs is selectively expressed in stromal fibroblasts. CYP1B1 is induced after binding or PAHs and TCDD to the AhR, but this response appears to very from cell to cell. The proposed research will elucidate mechanisms of regulation of CYP1B1 gene transcription and if the AhR is involved in this regulation. Key cis-regulatory elements will be identified with reporter gene constructs. Cis-elements regulating constitutive expression and TCDD/PAH activation of CYP1B1 will be deduced in the 1B1 upstream region. Associated in vivo changes in protein binding to cis-elements will be examined by PCR-enhanced footprinting. Protein complexes formed with key regulatory elements will be examined by gel shift mobility assays. The role of AhRin the regulation of 1B1 will be elucidated. Anomalies in the induction of 1B1 by PAH will be evaluated in terms of it localized intracellular depletion via metabolism at 1B1. In vivo expression will be analyzed in mouse tissue, where cell specificity of expression will be addressed. The role of the AhR in the expression of 1B1 will be dissected by use of AhR-deficient mice. The physiological function of 1B1 will be assessed by analysis of the effect of disruption of the 1B1 gene by homologous recombination in transgenic mice.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA016265-25
Application #
6172605
Study Section
Special Emphasis Panel (ZRG2-CPA (01))
Program Officer
Liu, Yung-Pin
Project Start
1977-04-01
Project End
2002-02-28
Budget Start
2000-07-01
Budget End
2002-02-28
Support Year
25
Fiscal Year
2000
Total Cost
$225,893
Indirect Cost

  Institution

Name
University of Wisconsin Madison
Department
Pharmacology
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715

  Publications

Halberg, Richard B; Larsen, Michele Campaigne; Elmergreen, Tammy L et al. (2008) Cyp1b1 exerts opposing effects on intestinal tumorigenesis via exogenous and endogenous substrates. Cancer Res 68:7394-402
Zheng, Wenchao; Jefcoate, Colin R (2005) Steroidogenic factor-1 interacts with cAMP response element-binding protein to mediate cAMP stimulation of CYP1B1 via a far upstream enhancer. Mol Pharmacol 67:499-512
Cho, Young C; Zheng, Wenchao; Yamamoto, Megumi et al. (2005) Differentiation of pluripotent C3H10T1/2 cells rapidly elevates CYP1B1 through a novel process that overcomes a loss of Ah Receptor. Arch Biochem Biophys 439:139-53
Cho, Young C; Zheng, Wenchao; Jefcoate, Colin R (2004) Disruption of cell-cell contact maximally but transiently activates AhR-mediated transcription in 10T1/2 fibroblasts. Toxicol Appl Pharmacol 199:220-38
Zheng, Wenchao; Brake, Paul B; Bhattacharyya, Kalyan K et al. (2003) Cell selective cAMP induction of rat CYP1B1 in adrenal and testis cells. Identification of a novel cAMP-responsive far upstream enhancer and a second Ah receptor-dependent mechanism. Arch Biochem Biophys 416:53-67
Zhang, Leying; Zheng, Wenchao; Jefcoate, Colin R (2003) Ah receptor regulation of mouse Cyp1B1 is additionally modulated by a second novel complex that forms at two AhR response elements. Toxicol Appl Pharmacol 192:174-90
Eltom, S E; Zhang, L; Jefcoate, C R (1999) Regulation of cytochrome P-450 (CYP) 1B1 in mouse Hepa-1 variant cell lines: A possible role for aryl hydrocarbon receptor nuclear translocator (ARNT) as a suppressor of CYP1B1 gene expression. Mol Pharmacol 55:594-604
Ikegwuonu, F I; Christou, M; Jefcoate, C R (1999) Regulation of cytochrome P4501B1 (CYP1B1) in mouse embryo fibroblast (C3H10T1/2) cells by protein kinase C (PKC). Biochem Pharmacol 57:619-30
Brake, P B; Arai, M; As-Sanie, S et al. (1999) Developmental expression and regulation of adrenocortical cytochrome P4501B1 in the rat. Endocrinology 140:1672-80
Alexander, D L; Zhang, L; Foroozesh, M et al. (1999) Metabolism-based polycyclic aromatic acetylene inhibition of CYP1B1 in 10T1/2 cells potentiates aryl hydrocarbon receptor activity. Toxicol Appl Pharmacol 161:123-39

Showing the most recent 10 out of 51 publications