Nishimori Hiroyuki, Sasaki Yasushi, Yoshida Koichi, Irifune Hideto, Zembutsu Hitoshi, Tanaka Toshihiro, Aoyama Tomoki, Hosaka Taisuke, Kawaguchi Satoshi, Wada Takuro, Hata Jun-Ichi, Toguchida Junya, Nakamura Yusuke, Tokino Takashi
Department of Molecular Biology, Cancer Research Institute, Sapporo Medical University School of Medicine, S-1, W-17, Chuo-ku, Sapporo, 060-8556, Japan.
Oncogene. 2002 Nov 28;21(54):8302-9. doi: 10.1038/sj.onc.1206025.
We report here that the Id2 (inhibitor of DNA binding 2) gene is a novel target of transcriptional activation by EWS-FLI1 and EWS-ERG, two fusion proteins that characterize Ewing family tumors (EFTs). To identify downstream targets of these EWS-ETS fusion proteins, we introduced EWS-ETS fusion constructs into a human fibrosarcoma cell line by retroviral transduction. cDNA microarray analysis revealed that Id2 expression was up-regulated by introducing the EWS-ETS fusion gene but not by the normal full-length ETS gene. An Id2 promoter-luciferase reporter assay showed that transactivation by EWS-ETS involves the minimal Id2 promoter and may function in cooperation with c-Myc within the full-length regulatory region. A chromatin immunoprecipitation assay revealed direct interaction between the Id2 promoter and EWS-FLI1 fusion protein in vivo. Significantly higher expression of Id2 and c-Myc was observed in all of the six EFT cell lines examined compared to six other sarcoma cell lines. Moreover, high levels of Id2 expression were also observed in five of the six primary tumors examined. Id2 is generally thought to affect the balance between cell differentiation and proliferation in development and is highly expressed in several cancer types. Considering these previous studies, our data suggest that the oncogenic effect of EWS-ETS may be mediated in part by up-regulating Id2 expression. doi:10.1038/sj.onc.1206025
我们在此报告，Id2（DNA结合抑制因子2）基因是EWS-FLI1和EWS-ERG转录激活的一个新靶点，这两种融合蛋白是尤因家族肿瘤（EFT）的特征性蛋白。为了鉴定这些EWS-ETS融合蛋白的下游靶点，我们通过逆转录病毒转导将EWS-ETS融合构建体导入人纤维肉瘤细胞系。cDNA微阵列分析显示，导入EWS-ETS融合基因可上调Id2表达，但导入正常全长ETS基因则无此作用。Id2启动子-荧光素酶报告基因检测表明，EWS-ETS的反式激活作用涉及最小Id2启动子，且可能在全长调控区域内与c-Myc协同发挥作用。染色质免疫沉淀分析揭示了Id2启动子与EWS-FLI融合蛋白在体内的直接相互作用。与其他六种肉瘤细胞系相比，在所检测的所有六种EFT细胞系中均观察到Id2和c-Myc的表达显著更高。此外，在所检测的六个原发性肿瘤中的五个中也观察到高水平的Id2表达。Id2通常被认为在发育过程中影响细胞分化和增殖之间的平衡，并且在几种癌症类型中高表达。考虑到这些先前的研究，我们的数据表明EWS-ETS的致癌作用可能部分是通过上调Id2表达来介导的。doi:10.1038/sj.onc.1206025
