Klotz D M, Beckman B S, Hill S M, McLachlan J A, Walters M R, Arnold S F
Tulane-Xavier Center for Bioenvironmental Research, Tulane University Medical Center, New Orleans, LA, USA.
Environ Health Perspect. 1996 Oct;104(10):1084-9. doi: 10.1289/ehp.961041084.
Environmental chemicals that function as estrogens have been suggested to be associated with an increase in disease and dysfunctions in animals and humans. To characterize chemicals that may act as estrogens in humans, we have compared three in vitro assays which measure aspects of human estrogen receptor (hER)-mediated estrogenicity. Chemicals were first tested for estrogen-associated transcriptional activity in the yeast estrogen screen (YES). This was created by expressing hER and two estrogen response elements linked to the lacZ gene in yeast. Second, chemicals that were tested in YES were then assayed for direct interaction with hER in a competition binding assay. Third, chemicals were tested in the estrogen-responsive MCF-7 human breast cancer cell line transiently transfected with a plasmid containing two estrogen response elements linked to the luciferase gene. Together, these assays have identified two metabolites of DDT, o,p'-DDD and p,p'-DDD, that have estrogenic activity. Interestingly, previous studies had reported that the DDD metabolites were nonestrogenic in whole animal models. Alachlor, the most frequently used herbicide in the United States, cis-nonachlor, and trans-nonachlor displayed weak estrogenic activity in the combined assays. The antifungal agent benomyl had no estrogenic activity. We propose that a combination of in vitro assays can be used in conjunction with whole animal models for a more complete characterization of chemicals with estrogenic activity.
有研究表明，具有雌激素功能的环境化学物质与动物和人类疾病及功能障碍的增加有关。为了鉴定可能在人体内发挥雌激素作用的化学物质，我们比较了三种体外试验，这些试验用于检测人类雌激素受体（hER）介导的雌激素效应的各个方面。首先，在酵母雌激素筛选试验（YES）中检测化学物质与雌激素相关的转录活性。该试验通过在酵母中表达hER和与lacZ基因相连的两个雌激素反应元件来实现。其次，对在YES试验中检测过的化学物质进行竞争性结合试验，以检测其与hER的直接相互作用。第三，将化学物质在雌激素反应性MCF-7人乳腺癌细胞系中进行检测，该细胞系已用含有与荧光素酶基因相连的两个雌激素反应元件的质粒进行瞬时转染。综合这些试验，已鉴定出滴滴涕的两种代谢产物o,p'-滴滴滴和p,p'-滴滴滴具有雌激素活性。有趣的是，之前的研究报告称，滴滴滴代谢产物在整个动物模型中无雌激素活性。在美国使用最频繁的除草剂甲草胺、顺式九氯和反式九氯在综合试验中显示出较弱的雌激素活性。抗真菌剂苯菌灵没有雌激素活性。我们建议，体外试验可与整个动物模型结合使用，以便更全面地鉴定具有雌激素活性的化学物质。
