E-Screen assays

Soto AM, Sonnenschein C, Chung KL, et al. 1995. The E-SCREEN assay as a tool to identify estrogens An update on estrogenic environmental pollutants. Environ Health Perspect 103 (Supp. 

Soto, A.M., Sonnenschein, C., and Chung, K.L. et al. (1995). The E-screen assay as a tool to identify estrogens—an update on estrogenic environmental-pollutants. Environmental Health Perspectives 103, 113-122. 

Linear alcohols were studied using MCF7 cells in the proliferation assay and in the expression of estrogen-dependent genes (Table 7.3.4). The AS C12 i4, its ethoxylated derivative (ALFONIC 1214) and linear alcohols from nonanol to dodecanol increase cell proliferation in the E-Screen assay. This effect was seen at 10-100 xM concentrations and,... 

The natural female steroid hormone with the greatest estrogenic activity is 17C-estradiol. It is important to note that some synthetic estrogens, such as diethylstilbestrol (DES), moxestrol, and ll)8-chloromethyl estradiol show 10 times more estrogenic activity than 17)8-estradiol in the E-SCREEN assay [136]. Ethinylestradiol has the same estrogenic activity as 17/1-estradiol, whereas the activity of the synthetic EDCs is by some orders of magnitude lower [136]. In this context it is important to note that most, if not all, efflu-... 

In Table 6 the physico-chemical properties, chemical structures, and some other relevant data of some natural estrogens, synthetic estrogens, and of some environmental man-made EDCs are compiled, as is the estrogenic activity measured as the relative proHferative potency on human breast cancer MCE 7 cells in the E-SCREEN assay [136] and in the recombinant yeast cell estrogen screening assay (RCBA) [138b]. In the last column of Table 6 their occurrence in the aquatic environment and their bioconcentration factors in fish and mussels are presented also as far as these data were pubHshed. 

RPP Relative proliferative potency is the ratio between 17)0-estradiol and the xenobiotic doses needed to produce maximal cell yields x 100 (E-SCREEN assay of Soto et al.) [136]. All data from Ref. [136] as otherwise noted. 

JEPA examined the literature on SDs and STs to determine whether risk assessment was really necessary. Except for the estrogenic effects, it was decided that the assessment was not necessary. Additional examinations were performed on ER binding assay, proliferation of MCF-7 human breast cancer cells (E-screen assay), yeast two hybrid assay and yeast estrogen selective (YES) assay [12]. From the results of these examinations, it was judged that estimating the risk of SDs and STs is not necessary at the present time. JEPA officially announced a revised edition of SPEED 98 in 2000, in which SDs and STs had been deleted from the list of EDs along with n-butylbenzene. 

So far only two inter-laboratory exercises have been published by Andersen et al. (1999) and Dhooge et al. (2006). The first is comparing ten in-vitro assays and one in-vivo assay performed by ten different laboratories. The inter-laboratory consist of three laboratories performing the E-SCREEN assay, four laboratories performing... 

Vanparys C, Depiereux S, Nadzialek S, Robbens J, Blust R, Kestemont P, De CW (2010) Performance of the flow cytometric E-screen assay in screening estrogenicity of pure compounds and environmental samples. Sci Total Environ 408 (20 ) 4451 460... 

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