Zhu Zheying, Edwards Robert J, Boobis Alan R
Department of Experimental Medicine and Toxicology, Imperial College London, London, United Kingdom.
Environ Health Perspect. 2009 Jun;117(6):928-34. doi: 10.1289/ehp.0800109. Epub 2009 Feb 7.
There is concern about the potential risk posed by compounds with estrogen-like activity present in the environment. As previous studies have shown that combined exposure to such compounds results in dose additivity, it should be possible to assess estrogen exposure with suitable biomarkers of effect.
Our goal was to identify candidate protein biomarkers of effect for estrogenic compounds.
In the search for biomarkers, we assessed the effect of several estrogenic compounds on the expression profile of proteins in breast-derived cell lines varying in their estrogen receptor (ER) phenotype using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. We identified responsive proteins, after separating them by SDS-polyacrylamide gel electrophoresis, and analyzing the trypsin-digested proteins by tandem mass spectrometry.
The estrogenic compounds 17beta-estradiol, genistein, bisphenol A, and endosulfan produced similar protein profile changes in MCF-7 cells (phenotype: ERalpha(+)/ERbeta(+)), but had no effect on MDA-MB-231 (ERalpha(-)/ERbeta(+)), MCF-10F (ERalpha(-)/ERbeta(+)), or MCF-10A (ERalpha(-)/ERbeta(-)) cells. The most responsive proteins in MCF-7 cells were identified as histones H2A, H2B, H3, and H4. Histone levels were not increased in cell lines that showed no proliferative response to estrogens despite their rapid intrinsic growth rate in culture.
Our results indicate that ER-mediated cell proliferation results in up-regulation of core histone proteins.
环境中存在具有雌激素样活性的化合物，人们对其潜在风险表示担忧。既往研究表明，联合暴露于此类化合物会导致剂量相加，因此应该可以通过合适的效应生物标志物来评估雌激素暴露情况。
我们的目标是识别雌激素化合物效应的候选蛋白质生物标志物。
在寻找生物标志物的过程中，我们使用表面增强激光解吸/电离飞行时间质谱法，评估了几种雌激素化合物对雌激素受体（ER）表型不同的乳腺来源细胞系中蛋白质表达谱的影响。我们通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离响应蛋白，并用串联质谱法分析胰蛋白酶消化后的蛋白质，从而鉴定出响应蛋白。
雌激素化合物17β-雌二醇、染料木黄酮、双酚A和硫丹在MCF-7细胞（表型：ERα(+)/ERβ(+)）中产生了相似的蛋白质谱变化，但对MDA-MB-231（ERα(-)/ERβ(+)）、MCF-10F（ERα(-)/ERβ(+)）或MCF-10A（ERα(-)/ERβ(-)）细胞没有影响。MCF-7细胞中反应最强烈的蛋白质被鉴定为组蛋白H2A、H2B、H3和H4。尽管某些细胞系在培养中固有生长速度很快，但对雌激素无增殖反应的细胞系中组蛋白水平并未升高。
我们的结果表明，ER介导的细胞增殖导致核心组蛋白的上调。
