WP2 Chemical and Biological Analysis of Endocrine Disrupting Compounds
255 Portland Ballroom
1:20 PM - 4:40 PM, Wednesday
() A Cell Culture Based Assay for the Measurement of Xenobiotic Effects on Steroid Production.
Jones, P1, Hecker, M1, Gracia, T1, Zhang, X1, 4, Sanderson, J2, Giesy, J1, 4, Newsted, J3, 1 Zoology Dept & Nat.Food Safety and Toxicology Center, Michigan State University, East Lansing, MI, USA4 City University of Hong Kong, Hong Kong, SAR, China2 Institute for Risk Assessment Sciences (IRAS), University of Utrecht, Utrecht, The Netherlands3 ENTRIX Inc., East Lansing, MI, USA
ABSTRACT- ′Endocrine disruption′ may not solely be produced by receptor mediated processes but may also occur through indirect mechanisms. Here we report the development of a method for the evaluation of potential effects of environmental chemicals on steroidogenesis. Production of steroid hormones was quantified in a steroid producing human cell line (H295R). To ensure ′portability′ of the assay system steroid production was quantified using commercially available ELISA systems. ELISA results were confirmed by GC/MS techniques. After 72 hours culture H295R culture media contained an average of 26 ng/ml testosterone (T) (n=3) and 5.6 ng/ml estradiol (E2) (n=3). The H295R cells contained only 5-6% of the T and E2 present in the culture system. The effects of exposure to model chemicals known to affect expression of steroidogenic genes were investigated. When measured by GC/MS, treatment with aminoglutethimide reduced the T concentration in the culture medium to 45% of control levels while treatment with progesterone decreased T concentrations to 35% of control levels. Previous results have demonstrated that inducers of steroidogenesis altered the expression of a range of enzymes. Expression of CYP11B2 and 3-
-HSD were increased in excess of 10 fold by treatment with 8-Br-cAMP and forskolin. While Phorbol-12-myristate-13-acetate increased CYP19 expression over 10-fold it decreased CYP17 expression by almost 90%. Alterations in steroid production were correlated to alterations in steroid production. The assay system developed provides a means for assessing the impacts of chemical contaminants on the production of steroid hormones.
Key words: bioassay, hormones, steroidogenesis, gene expression