GENETICALLY-ENGINEERED CELLS STABLY EXPRESSING CYTOCHROME-P450 AND THEIR APPLICATION TO MUTAGEN ASSAYS

Citation
M. Sawada et T. Kamataki, GENETICALLY-ENGINEERED CELLS STABLY EXPRESSING CYTOCHROME-P450 AND THEIR APPLICATION TO MUTAGEN ASSAYS, Mutation research. Reviews in mutation research, 411(1), 1998, pp. 19-43
Citations number
152
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Genetics & Heredity",Toxicology,"Biothechnology & Applied Migrobiology
ISSN journal
1383-5742
Volume
411
Issue
1
Year of publication
1998
Pages
19 - 43
Database
ISI
SICI code
1383-5742(1998)411:1<19:GCSECA>2.0.ZU;2-1
Abstract
Genetically engineered cells transiently and stably expressing cytochr ome P450 (P450), a key enzyme for biotransformation of a wide variety of compounds, have provided new tools for investigation of P450 functi ons such as P450-mediated metabolic activation of chemicals. This revi ew will focus on the development of mammalian cell lines stably expres sing P450s and application to toxicology testings. Stable expression s ystems have an advantage over transient ones in that a series of the p rocess from metabolic activation of test compounds to the appearance o f toxicological consequences occurs entirely in the same intact cells. Indeed, many cell lines stably expressing a single form of mammalian P450 have been established so far and applied to cytotoxic or genotoxi c assays, the endpoints of which contained mutations at hprt and other gene loci, chromosomal aberrations, sister chromatid exchanges, micro nuclei, morphological transformation, and P-32-postlabeling. Analyses of metabolites of toxic substances have also been carried out, using t he intact cells or microsomal fractions prepared from the cells. The s table expression systems clearly indicate the form of P450 enzyme capa ble of activating a certain chemical. More recently, coexpression of P 450 together with other components of microsomal electron transfer sys tems such as NADPH-cytochrome P450 reductase has been successfully per formed to increase the metabolic capacity of the heterologously expres sed P450. In addition, to reconstruct the entire metabolic activation system for certain heterocyclic amines, cell lines which simultaneousl y express a form of human P450 and a phase II enzyme, N-acetyltransfer ase, were established. These cells were highly sensitive to some carci nogenic heterocyclic amines. In genetic toxicology, such a coexpressio n system for two or more enzymes will provide useful materials which m imic in vivo activation systems. (C) 1998 Elsevier Science B.V. All ri ghts reserved.