Tee Meng Kian, Rogatsky Inez, Tzagarakis-Foster Christina, Cvoro Aleksandra, An Jinping, Christy Robert J, Yamamoto Keith R, Leitman Dale C
Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Francisco, San Francisco, California 94143-0556, USA.
Mol Biol Cell. 2004 Mar;15(3):1262-72. doi: 10.1091/mbc.e03-06-0360. Epub 2003 Dec 29.
Estrogens and selective estrogen receptor modulators (SERMs) interact with estrogen receptor (ER) alpha and beta to activate or repress gene transcription. To understand how estrogens and SERMs exert tissue-specific effects, we performed microarray analysis to determine whether ERalpha or ERbeta regulate different target genes in response to estrogens and SERMs. We prepared human U2OS osteosarcoma cells that are stably transfected with a tetracycline-inducible vector to express ERalpha or ERbeta. Western blotting, immunohistochemistry, and immunoprecipitation studies confirmed that U2OS-ERalpha cells synthesized only ERalpha and that U2OS-ERbeta cells expressed exclusively ERbeta. U2OS-ERalpha and U2OS-ERbeta cells were treated either with 17beta-estradiol (E2), raloxifene, and tamoxifen for 18 h. Labeled cRNAs were hybridized with U95Av2 GeneChips (Affymetrix). A total of 228, 190, and 236 genes were significantly activated or repressed at least 1.74-fold in U2OS-ERalpha and U2OS-ERbeta cells by E2, raloxifene, and tamoxifen, respectively. Most genes regulated in ERalpha cells in response to E2, raloxifene, and tamoxifen were distinct from those regulated in ERbeta cells. Only 38 of the 228 (17%) genes were regulated by E2 in both U2OS-ERalpha and U2OS-ERbeta cells. Raloxifene and tamoxifen regulated only 27% of the same genes in both the ERalpha and ERbeta cells. A subset of genes involved in bone-related activities regulated by E2, raloxifene, and tamoxifen were also distinct. Our results demonstrate that most genes regulated by ERalpha are distinct from those regulated by ERbeta in response to E2 and SERMs. These results indicate that estrogens and SERMs exert tissue-specific effects by regulating unique sets of targets genes through ERalpha and ERbeta
雌激素和选择性雌激素受体调节剂（SERM）与雌激素受体（ER）α和β相互作用，以激活或抑制基因转录。为了解雌激素和SERM如何发挥组织特异性作用，我们进行了微阵列分析，以确定ERα或ERβ是否响应雌激素和SERM调节不同的靶基因。我们制备了稳定转染四环素诱导载体以表达ERα或ERβ的人U2OS骨肉瘤细胞。蛋白质印迹、免疫组织化学和免疫沉淀研究证实，U2OS-ERα细胞仅合成ERα，而U2OS-ERβ细胞仅表达ERβ。U2OS-ERα和U2OS-ERβ细胞分别用17β-雌二醇（E2）、雷洛昔芬和他莫昔芬处理18小时。标记的cRNA与U95Av2基因芯片（Affymetrix）杂交。E2、雷洛昔芬和他莫昔芬分别在U2OS-ERα和U2OS-ERβ细胞中使总共228、190和236个基因显著激活或抑制至少1.74倍。ERα细胞中响应E2、雷洛昔芬和他莫昔芬调节的大多数基因与ERβ细胞中调节的基因不同。在U2OS-ERα和U2OS-ERβ细胞中，228个基因中只有38个（17%）受E2调节。雷洛昔芬和他莫昔芬在ERα和ERβ细胞中仅调节27%的相同基因。E2、雷洛昔芬和他莫昔芬调节的参与骨相关活动的一组基因也不同。我们的结果表明，响应E2和SERM，ERα调节的大多数基因与ERβ调节的基因不同。这些结果表明，雌激素和SERM通过ERα和ERβ调节独特的靶基因集发挥组织特异性作用。
