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(059) The ER-CALUX reporter gene assay as biomarker of estrogenic activity in environmental and biological matrices. Legler, Juliette1,2, Jonas, Arjen2,4, Lahr, Joost3, Brouwer, Abraham4, Vethaak, Dick5, Vanderburg, Bart1, Murk, Tinka2, 1 2 4 3 5 ABSTRACT- The recently developed estrogen receptor-mediated chemical activated luciferase reporter gene expression(ER-CALUX)assay in stably transfected T47D human breast cancer cells was studied as a biomarker for exposure to (xeno-)estrogens in environmental matrices, as well as a biomarker for internal dose of (xeno-)estrogens using biological samples. Complex mixtures of compounds present in sediments from various marine locations in The Netherlands were tested. More polar fractions of acetone-hexane sediment extracts obtained from industrialized areas such as the Port of Rotterdam showed the highest estrogenic potency of the sediments tested (up to 40 pmol estradiol equivalents (EEQ) per gram sediment). In testing biological samples in the ER-CALUX assay, estrogen glucuronides in urine obtained from human males and females, as well as in male fish bile, were converted to active forms following incubation with B-glucuronidase or live E. coli cells. These results indicate that bacterial hydrolysis may form a major contribution to the levels of estrogenic substances found in the environment. The highest estrogenic activity was found in deconjugated metabolites from urine of a pregnant woman, in which levels up to 3000 nmol EEQ/l urine were found following overnight incubation with E. coli. In bile from male fish sampled from various freshwater and marine locations, high estrogenic activity of deconjugated bile metabolites correlated with elevated EEQs in surface water samples as well as vitellogenin induction. Measurement of (deconjugated) bile and urine metabolites may form a useful biomarker for internal dose of (xeno-)estrogens in males. Key words: (xeno-)estrogens, sediments, urine, bile |
