title: Application of statistical experimental design and multivariate data analysis for evaluation of mixtures using cytochrome P4501A induction.
abstract: Cytochrome P4501A (CYP1A) induction was evaluated in the rat hepatoma cell line H4IIE as a biomarker of exposure to organic compounds. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay was performed to assess the viability of cells exposed to environmentally relevant concentrations of cadmium. Cadmium concentrations greater than approximately 0.7 microM were found to affect cell viability. Cells were exposed to environmentally relevant concentrations of 3,3',4,4'-tetrachlorobiphenyl (PCB 77) or benzo[a]pyrene (BaP) and to combinations of PCB 77, BaP, and cadmium based on a statistical experimental design. Quantification of CYP1A proteins using Western blot analysis showed that both BaP and PCB 77 induced CYP1A in a concentration-dependent manner up to 5 microM. Response surface modeling for evaluation of the combined effect of compounds was conducted using the multivariate regression model projection to latent structures (PLS). Analysis of response surface models for the ternary mixtures indicated antagonistic interactions between BaP and PCB 77 and a possible inhibitory effect of cadmium on PCB 77- induced CYP1A. Use of CYP1A induction in the H4IIE cell line with immunodetection of CYP1A proteins, combined with the application of response surface design and PLS, is shown to be a suitable strategy for evaluating combined effects in pollutant mixtures.
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors.forename: Maria Helene Steinnes
authors.initials: MH
authors.lastname: Jensen
authors.forename: Ase
authors.initials: A
authors.lastname: Krøkje
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity; D001681:Biological Assay; D002104:Cadmium / Q000032:analysis / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D019363:Cytochrome P-450 CYP1A1 / Q000032:analysis* / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D015233:Models, Statistical; D015999:Multivariate Analysis; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D051381:Rats; D012044:Regression Analysis; D012107:Research Design
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D002104:Cadmium; D001564:Benzo(a)pyrene; D011078:Polychlorinated Biphenyls; D019363:Cytochrome P-450 CYP1A1; C028451:3,4,3',4'-tetrachlorobiphenyl