The Id2 gene is a novel target of transcriptional activation by EWS-ETS fusion proteins in Ewing family tumors.
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
Nishimori
Hiroyuki
H
Department of Molecular Biology, Cancer Research Institute, Sapporo Medical University School of Medicine, S-1, W-17, Chuo-ku, Sapporo, 060-8556, Japan.
Sasaki
Yasushi
Y
Yoshida
Koichi
K
Irifune
Hideto
H
Zembutsu
Hitoshi
H
Tanaka
Toshihiro
T
Aoyama
Tomoki
T
Hosaka
Taisuke
T
Kawaguchi
Satoshi
S
Wada
Takuro
T
Hata
Jun-Ichi
J
Toguchida
Junya
J
Nakamura
Yusuke
Y
Tokino
Takashi
T
D001483:Base Sequence; D015152:Blotting, Northern; D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation; D006801:Humans; D051797:Inhibitor of Differentiation Protein 2; D020411:Oligonucleotide Array Sequence Analysis; D034802:RNA-Binding Protein EWS / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics*; D012097:Repressor Proteins; D012512:Sarcoma, Ewing / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C497450:ID2 protein, human; D051797:Inhibitor of Differentiation Protein 2; D034802:RNA-Binding Protein EWS; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors