Evaluation of a Recombinant Yeast Cell Estrogen Screening Assay

Coldham, N. G.; Dave, Mehul; Sivapathasundaram, Susila; McDonnell, Donald P.; Connor, Caroline M.; Sauer, Maurice J.

doi:10.2307/3433729

Cited by 138 publications

(195 citation statements)

References 31 publications

Supporting

Mentioning

180

Contrasting

Unclassified

Order By: Relevance

“…A significant aspect of our study is that the estrogenic effects of BPA were found at much lower dose levels than would have been expected from previous studies (Coldham et al, 1997;Ashby and Tinwell, 1998). This is particularly true of the rat uterotrophic assays conducted in this study for 3 consecutive daily administrations of the test chemicals.…”

Section: Discussioncontrasting

confidence: 38%

Potential estrogenic effects of bisphenol-A estimated by in vitro and in vivo combination assays.

et al. 2001

View full text Add to dashboard Cite

The potential estrogenic activities of bisphenol-A were investigated in vitro (E-screen and estrogen receptor competitive binding bioassays) and in vivo (uterotrophic assay). Uterotrophic responses were evaluated using mature ovariectomized Sprague-Dawley female rats treated subcutaneously with bisphenol A (1, 5, 10, 50, and 100 mg/kg/day), E2 (0.3 /kg), and DES (0.3 /kg) for 3 consecutive days. In a MCF-7 cell proliferation assay, E2 and DES used as positive estrogens induced maximum proliferation of MCF-7 cells at 1.0 nM, whereas BPA slightly induced MCF-7 cell proliferation at a higher level of 0.1 M and maximum proliferation at 10 M. In a competitive binding assay, E2 and DES showed inhibition of 17 -[ 3 H]estradiol binding to the rat uterus ER with an IC50 of 1.0 nM and 0.5 M, respectively. However, BPA had an IC50 of 5 M, which was approximately 5,000 or 10,000-fold greater than the IC50 of E2 and DES. In uterotrophic assays, uterus (wet and blotted) and vagina weights were significantly increased at the dose of BPA 100 mg/kg/day in OVX Sprague-Dawley rats. These studies demonstrate that BPA exhibits weak estrogenic activity in all experimental systems, and thus its migration from epoxy resins or polycarbonate products should be controlled not to exceed a safety levels for humans.

show abstract

Section: Discussioncontrasting

confidence: 38%

Potential estrogenic effects of bisphenol-A estimated by in vitro and in vivo combination assays.

et al. 2001

View full text Add to dashboard Cite

show abstract

“…First, the in vivo activity of DES in altering gene expression is much higher than that of E2. This correlates with the estrogenic activities of E2 and DES estimated by the prepubertal mouse (Coldham et al 1997), although the extent of the difference was greater than the result in prepubertal mouse. The difference between the two systems may be due to the presence in vivo of binding proteins such as steroid hormone-binding globulin, which binds to DES more weakly than it binds to E2 (Sheehan & Young 1979), causing more DES to be available for ER binding.…”

Section: Dose-dependent Activation Of Genes By Physiological and Non-mentioning

confidence: 86%

“…1). This suggests that E2 and DES are not identical in their gene activation behavior despite a study with yeast reporter assays that revealed the two estrogens had a very similar effect on the genes examined (Korach et al 1985, Coldham et al 1997.…”

Section: Different Effects Of Physiological and Non-physiological Estmentioning

confidence: 99%

Similarities and differences in uterine gene expression patterns caused by treatment with physiological and non-physiological estrogens

Watanabe¹,

Suzuki²,

Kobayashi³

et al. 2003

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

Administration of physiological and non-physiological estrogens during pregnancy or after birth is known to have adverse effects on the development of the reproductive tract and other organs. Although it is believed that both estrogens have similar effects on gene expression, this view has not been tested systematically. To compare the effects of physiological (estradiol; E2) and non-physiological (diethylstilbestrol; DES) estrogens, we used DNA microarray analysis to examine the uterine gene expression patterns induced by the two estrogens. Although E2 and DES induced many genes to respond in the same way, different groups of genes showed varying levels of maximal activities to each estrogen, resulting in different dose-response patterns. Thus, each estrogen has a distinct effect on uterine gene expression. The genes were classified into clusters according to their dose-responses to the two estrogens. Of the eight clusters, only two correlated well with the uterotropic effect of different doses of E2. One of these clusters contained genes that were upregulated by E2, which included genes encoding several stress proteins and transcription factors. The other cluster contained genes that were downregulated by E2, including genes related to metabolism, transcription and detoxification processes. The expression of these genes in estrogen receptor-deficient mice was not affected by E2 treatment, indicating that these genes are affected by the E2-bound estrogen receptor. Thus, of the many genes that are affected by estrogen, it was suggested that only a small number are directly involved in the uterotropic effects of estrogen treatment.

show abstract

“…Animal cell-based and yeast-based transactivation systems have been used (13). One of the most widely applied in vitro assays uses genetically modified yeast strains that harbor an estrogen receptor expression cassette and a reporter construct (6,14,15). Interaction of an estrogenic substance with the estrogen receptor causes a conformational change in the receptor, enabling the estrogen-estrogen receptor complex to bind to estrogen-responsive elements.…”

mentioning

confidence: 99%

Optimization of a yeast estrogen screen and its applicability to study the release of estrogenic isoflavones from a soygerm powder.

Boever

Demaré

Vanderperren

et al. 2001

Environ Health Perspect

View full text Add to dashboard Cite

Here we describe a redesigned protocol of the yeast estrogen screen developed by Routledge and Sumpter. The redesigned test comprises two steps. First, a large amount of yeast with estrogenic compounds is incubated for 24 hr. Subsequently, a mixture of cycloheximide and the chromogenic substrate chlorophenol red-beta-d-galactopyranoside (CPRG) is added. The cycloheximide stops protein synthesis and allows for an end-point measurement of beta-galactosidase activity generated during the first 24 hr. CPRG is converted to chlorophenol red and reflects beta-galactosidase activity, which is indicative of the estrogenic activity. The modifications shorten the duration of the assay at least 1 day and avoid interference of the estrogenic CPRG or chlorophenol red. The redesigned and the original protocol were used to study the estrogenic activity of bisphenol A, methoxychlor, p,p'-DDT, and isoflavones (genistein, daidzein, and glycitein). Bisphenol A, methoxychlor, and genistein triggered higher levels of beta-galactosidase activity in the redesigned protocol. Estrogenic activity of p,p'-DDT could only be demonstrated with the redesigned protocol. Glycitein and daidzein failed to give a response with both protocols. We also studied deconjugation of beta-glycosidic isoflavones present in soygerm powder. Treatment of the soygerm powder with beta-glycosidase released isoflavones. The estrogenic response of the samples was confirmed with the redesigned protocol and correlated with the amount of genistein present. The release of isoflavones under conditions prevailing in the intestines was studied. Bacterial beta-glycosidase present in the large intestine released isoflavones, and moderate estrogenic activity could be demonstrated.

show abstract

Evaluation of a Recombinant Yeast Cell Estrogen Screening Assay

Cited by 138 publications

References 31 publications

Potential estrogenic effects of bisphenol-A estimated by in vitro and in vivo combination assays.

Potential estrogenic effects of bisphenol-A estimated by in vitro and in vivo combination assays.

Similarities and differences in uterine gene expression patterns caused by treatment with physiological and non-physiological estrogens

Optimization of a yeast estrogen screen and its applicability to study the release of estrogenic isoflavones from a soygerm powder.

Contact Info

Product

Resources

About