title: DRE-CALUX bioassay in comparison with HRGC/MS for measurement of toxic equivalence in environmental samples.
abstract: CALUX, Chemically Activated LUciferase gene eXpression bioassay, has proven valuable for screening for and assessing toxic equivalents of dioxin-like compounds, because it detects all AhR (arylhydrocarbon receptor) ligands in a variety of sample matrices. In this study, we tried to validate DRE (dioxin-response elements)-CALUX bioassay, which has been developed by cloning mouse cyp1a1 gene in front of luciferase reporter gene. We compared DRE-CALUX bioassay with high resolution gas chromatography/mass spectrometry (HRGC/MS) for assessing environmental samples from Korea. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) dose response study showed high correlation (r2=0.89) between DRE-CALUX bioassay and EROD (ethoxyresorufin O-deethylase) bioassay, a commonly used bioassay method. The mean TEQ value of water samples was 0.57 pg-TEQ(HRGC/MS)/L and 4.97 pg-TEQ(CALUX)/L. For soil samples, HRGC/MS-TEQ values ranged from 0 to 47.18 pg-TEQ/g (dry) and correlated well (r2=0.98) with values obtained by CALUX-TEQ which ranged from 0.92 to 649.97 pg-TEQ/g (dry). The difference between the absolute TEQ values might be due to the presence of dioxin-like compounds without WHO-TEQ values rather than the difference between CALUX-REP and WHO-TEQ. Based on this study, we suggest that DRE-CALUX bioassay can serve as an alternative bioassay method for high-throughput analysis of large number of environmental samples.
authors.affiliation: College of Pharmacy, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-ku, Seoul 120-750, South Korea.
authors.forename: K E
authors.initials: KE
authors.lastname: Joung
authors.forename: Y H
authors.initials: YH
authors.lastname: Chung
authors.forename: Y Y
authors.initials: YY
authors.lastname: Sheen
mesh_terms: D001681:Biological Assay / Q000191:economics / Q000379:methods; D002460:Cell Line; D003001:Cloning, Molecular; D019363:Cytochrome P-450 CYP1A1 / Q000187:drug effects / Q000235:genetics; D004147:Dioxins / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D017930:Genes, Reporter; D007723:Korea; D008156:Luciferases / Q000187:drug effects / Q000235:genetics; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity; D018336:Receptors, Aryl Hydrocarbon / Q000187:drug effects / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis; D018675:Toxicity Tests / Q000191:economics / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D008156:Luciferases; D019363:Cytochrome P-450 CYP1A1