Estrogenic Activities of 517 Chemicals by Yeast Two-Hybrid Assay
01 Aug 2000-Journal of Health Science (The Pharmaceutical Society of Japan)-Vol. 46, Iss: 4, pp 282-298
TL;DR: A simple and rapid screening method using the yeast two-hybrid system based on the ligand-dependent interaction of nuclear hormone receptors with coactivators to test the estrogenic activity of chemicals.
Abstract: One of the urgent tasks in understanding endocrine disruptors (EDs) is to compile a list of suspected substances among the huge number of chemicals by using the screening test method. We developed a simple and rapid screening method using the yeast two-hybrid system based on the ligand-dependent interaction of nuclear hormone receptors with coactivators. To date, we have tested the estrogenic activity of more than 500 chemicals including natural substances, medicines, pesticides, and industrial chemicals. 64 compounds were evaluated as positive, and most of these demonstrated a common structure; phenol with a hydrophobic moiety at the para-position without bulky groups at the ortho-position. These results are expected to facilitate further risk assessment of chemicals.
Citations
More filters
01 Sep 2009
44 citations
Cites methods from "Estrogenic Activities of 517 Chemic..."
...TCEP, TnBP, and TBEP tested negative for estrogenic activity in a reporter gene expression assay using yeast cells (Nishihara et al. 2000)....
[...]
TL;DR: This work proposes a fast method for ligand detection for different vertebrate receptors in yeast, based on the use of fluorogenic substrates for the widely used reporter beta-galactosidase gene, which provides statistically rigorous procedures to distinguish between active and inactive compounds and to evaluate the fitness of the data to alternative models of dose/response mechanisms.
43 citations
TL;DR: The present microfluidic device can be used for highly sensitive detection of hormone active chemicals and the inhibitory effects of antagonists such as tamoxifen were detected electrochemically by using the device.
Abstract: Endocrine disruptors that act like hormones in the endocrine system might have toxic effects. Therefore, it is important to develop a portable device that can detect hormone active chemicals in samples rapidly and easily. In this study, a microfluidic device was developed for the detection of hormone active chemicals using genetically engineered yeast cells. The yeast cells were used as biosensors since they were genetically engineered to respond to the presence of hormone active chemicals by synthesizing beta-galactosidase (beta-gal). For achieving further sensitivity, we incorporated interdigitated array (IDA) electrodes (width, 1.2 microm; gap, 0.8 microm) with 40 electrode fingers into the analytical chamber of the microfluidic device. The yeast cells precultured with a hormone active chemical, 17beta-estradiol (E2), were trapped from the main channel of the device to the analytical camber by electrophoresis. After trapping in the analytical chamber, we performed electrochemical detection of beta-gal induced in the yeast cells with the IDA electrodes. Actually, electrochemical detection was performed on p-aminophenol that was converted from p-aminophenyl-beta-D-galactopyranoside with beta-gal. The electrochemical signals from the yeast cells precultured with 17beta-estradiol were successfully detected with the device. Furthermore, the inhibitory effects of antagonists such as tamoxifen were also detected electrochemically by using the device. Thus, the present microfluidic device can be used for highly sensitive detection of hormone active chemicals.
42 citations
TL;DR: To identify potential ligands, semiquantitative structure-activity relationships were developed for the complete set correlating the presence or lack of binding affinity to the estrogen receptor with structural features of the molecules.
Abstract: The main objective of this study was to evaluate the capability of 120 aromatic chemicals to bind to the human alpha estrogen receptor (hERα) by the use of quantum similarity methods. The experimental data were segregated into two categories, i.e., those compounds with and without estrogenicity activity (active and inactive). To identify potential ligands, semiquantitative structure−activity relationships were developed for the complete set correlating the presence or lack of binding affinity to the estrogen receptor with structural features of the molecules. The structure−activity relationships were based upon molecular similarity indices, which implicitly contain information related to changes in the electron distributions of the molecules, along with indicator variables, accounting for several structural features. In addition, the whole set was split into several chemical classes for modeling purposes. Models were validated by dividing the complete set into several training and test sets to allow for e...
42 citations
TL;DR: In this article, the authors used a DNA microarray containing estrogen responsive genes (EstrArray) to examine gene expression profiles in MCF-7 cells treated with 10 microM butylbenzyl phthalate (BBP), dibutyl phTHC (DBP), DEP and DIP along with the natural estrogen 17beta-estradiol ([E(2]], 10 nM), and found that BBP showed the highest correlation with E(2) (r = 0.85).
Abstract: Phthalates are used industrially as plasticizers and are known to contaminate natural environments, mostly as di-ester or mono-ester complexes. Because they are structurally similar to natural estrogens, they could act as endocrine disruptors. Here, we used a DNA microarray containing estrogen responsive genes (EstrArray) to examine gene expression profiles in MCF-7 cells treated with 10 microM butylbenzyl phthalate (BBP), dibutyl phthalate (DBP), diethyl phthalate (DEP), and diisopropyl phthalate (DIP) along with the natural estrogen 17beta-estradiol ([E(2)], 10 nM). The profiles for phthalate esters and E(2) were examined by correlation analysis using correlation coefficients (r-values) and cluster analysis. We found that BBP showed the highest correlation with E(2) (r = 0.85), and DEP and DIP showed moderate r-values (r = 0.52 and r = 0.49, respectively). Dibutyl phthalate exhibited the lowest (but still significant) correlation with E(2) (r = 0.36). Furthermore, among the pairs of chemicals, DEP-DIP and DIP-DBP showed very high correlations (r = 0.90 and r = 0.80, respectively), and the other pairs showed moderate relationships, which reflected how structurally close they are to each other. The analysis of six functional groups of genes (enzymes, signaling, proliferation, transcription, transport, and others) indicated that the genes belonging to the enzyme, transcription, and other functional groups showed common responses to phthalate esters and E(2). Although the effect of BBP was similar to that of E(2), the other phthalate esters showed different types of effects. These results indicate that the structure of estrogenic chemicals is strongly related to their estrogenic activity and can be evaluated by appropriate grouping of the responsive genes by focused microarray analysis.
42 citations
Cites background from "Estrogenic Activities of 517 Chemic..."
...phthalate (BBP), can induce estrogen receptor -mediated gene expression and proliferation of MCF-7 cells through their EDC activities [10,11]....
[...]
References
More filters
Book•
[...]
01 Jan 1996
TL;DR: The cause of disruptions in animal breeding cycles, accompanied by increases in birth defects, sexual abnormalities and reproductive failure, is traced to the pervasive presence in the environment of chemicals that mimic hormones and trick the reproductive system.
Abstract: For years, scientists have noticed disruptions in animal breeding cycles, accompanied by increases in birth defects, sexual abnormalities and reproductive failure. Humans are not immune either, with sperm counts dropping by as much as 50% in recent decades and with women seeing a rise in hormone-related cancers, endometriosis and other disorders. This book traces the cause of these aberrations and diseases to the pervasive presence in the environment of chemicals that mimic hormones and trick the reproductive system. The conclusions are as obvious as they are inescapable - unless we make vital changes in the way we manufacture and employ the artefacts of our "good life", there will be no life at all.
917 citations