Stossi Fabio, Barnett Daniel H, Frasor Jonna, Komm Barry, Lyttle C Richard, Katzenellenbogen Benita S
Department of Molecular and Integrative Physiology, University of Illinois, 524 Burrill Hall, 407 South Goodwin Avenue, Urbana, Illinois 61801-3704, USA.
Endocrinology. 2004 Jul;145(7):3473-86. doi: 10.1210/en.2003-1682. Epub 2004 Mar 19.
Estrogens exert many important effects in bone, a tissue that contains both estrogen receptors alpha and beta (ERalpha and ERbeta). To compare the actions of these receptors, we generated U2OS human osteosarcoma cells stably expressing ERalpha or ERbeta, at levels comparable with those in osteoblasts, and we characterized their response to 17beta-estradiol (E2) over time using Affymetrix GeneChip microarrays to determine the expression of approximately 12,000 genes, followed by quantitative PCR verification of the regulation of selected genes. Of the approximately 100 regulated genes we identified, some were stimulated by E2 equally through ERalpha and ERbeta, whereas others were selectively stimulated via ERalpha or ERbeta. The E2-regulated genes showed three distinct temporal patterns of expression over the 48-h time course studied. Of the functional categories of the E2-regulated genes, most numerous were those encoding cytokines and factors associated with immune response, signal transduction, and cell migration and cytoskeleton regulation, indicating that E2 can exert effects on multiple pathways in these osteoblast-like cell lines. Of note, E2 up-regulated several genes associated with cell motility selectively via ERbeta, in keeping with the selective E2 enhancement of the motility of ERbeta-containing cells. On genes regulated equally by E2 via ERalpha or ERbeta, the phytoestrogen genistein preferentially stimulated gene expression via ERbeta. These studies indicate both common as well as distinct target genes for these two ERs, and identify many novel genes not previously known to be under estrogen regulation.
雌激素在骨骼中发挥着许多重要作用，骨骼组织同时含有雌激素受体α和β（ERα和ERβ）。为了比较这些受体的作用，我们构建了稳定表达ERα或ERβ的U2OS人骨肉瘤细胞系，其表达水平与成骨细胞中的水平相当，并且我们使用Affymetrix GeneChip微阵列来确定约12,000个基因的表达，以表征它们随时间对17β-雌二醇（E2）的反应，随后通过定量PCR验证所选基因的调控情况。在我们鉴定出的约100个受调控基因中，有些基因通过ERα和ERβ被E2同等程度地刺激，而其他基因则通过ERα或ERβ被选择性地刺激。在研究的48小时时间进程中，E2调控的基因呈现出三种不同的时间表达模式。在E2调控基因的功能类别中，数量最多的是那些编码细胞因子以及与免疫反应、信号转导、细胞迁移和细胞骨架调控相关的因子的基因，这表明E2可以对这些成骨样细胞系中的多种途径产生影响。值得注意的是，E2通过ERβ选择性地上调了几个与细胞运动相关的基因，这与E2对含ERβ细胞运动性的选择性增强一致。对于通过ERα或ERβ被E2同等调控的基因，植物雌激素染料木黄酮优先通过ERβ刺激基因表达。这些研究表明了这两种ER的共同以及不同的靶基因，并鉴定出许多以前未知受雌激素调控的新基因。
