Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Benzene metabolism in human lung cell lines BEAS-2B and A549 cells overexpressing CYP2F1.

Authors
Sheets-PL; Yost-GS; Carlson-GP
Source
J Biochem Mol Toxicol 2004 Jan; 18(2):92-99
NIOSHTIC No.
20031166
Abstract
Benzene is an occupational and environmental toxicant. The main human health concern associated with benzene exposure is leukemia. The toxic effects of benzene are dependent on its metabolism by the cytochrome P450 enzyme system. The cytochrome P450 enzymes CYP2E1 and CYP2F2 are the major contributors to the bioactivation of benzene in rats and mice. Although benzene metabolism has been shown to occur with mouse and human lung microsomal preparations, little is known about the ability of human CYP2F to metabolize benzene or the lung cell types that might activate this toxicant. Our studies compared bronchiolar derived (BEAS-2B) and alveolar derived (A549) human cell lines for benzene metabolizing ability by evaluating the roles of CYP2E1 and CYP2F1. BEAS-2B cells that overexpressed CYP2F1 and recombinant CYP2F1 were also evaluated. BEAS-2B cells overexpressing the enzyme CYP2F1 produced 47.4 +/- 14.7 pmols hydroxylated metabolite/106 cells/45 min. The use of the CYP2E1-selective inhibitor diethyldithiocarbamate and the CYP2F2-selective inhibitor 5-phenyl-1-pentyne demonstrated that both CYP2E1 and CYP2F1 are important in benzene metabolism in the BEAS-2B and A549 human lung cell lines. The recombinant expressed human CYP2F1 enzyme had a Km value of 3.83 M and a Vmax value of 0.01 pmol/pmol P450 enzyme/min demonstrating a reasonably efficient catalysis of benzene metabolism (Vmax/Km = 2.6). Thus, these studies have demonstrated in human lung cell lines that benzene is bioactivated by two lung-expressed P450 enzymes.
Keywords
Environmental-health; Toxicology; Toxins; Toxic-effects; Metabolism; Benzenes; Lung; Lung-disorders; Liver; Liver-disorders; Pulmonary-system-disorders; Occupational-health; Occupational-hazards; Environmental-hazards
CODEN
JBMTFQ
CAS No.
71-43-2
Publication Date
20040101
Document Type
Journal Article
Email Address
gcarlson@purdue.edu
Funding Type
Grant
Fiscal Year
2004
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-T01-OH-008615
Issue of Publication
2
ISSN
1095-6670
Source Name
Journal of Biochemical and Molecular Toxicology
State
IN; UT
Performing Organization
Purdue University, School of Health Sciences, West Lafayette, Indiana
TOP