EWS/ATF1 expression induces sarcomas from neural crest–derived cells in mice
Kazunari Yamada, … , Akira Hara, Yasuhiro Yamada
Kazunari Yamada, … , Akira Hara, Yasuhiro Yamada
Published January 2, 2013
Citation Information: J Clin Invest. 2013;123(2):600-610. https://doi.org/10.1172/JCI63572.
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Research Article Oncology

EWS/ATF1 expression induces sarcomas from neural crest–derived cells in mice

Abstract

Clear cell sarcoma (CCS) is an aggressive soft tissue malignant tumor characterized by a unique t(12;22) translocation that leads to the expression of a chimeric EWS/ATF1 fusion gene. However, little is known about the mechanisms underlying the involvement of EWS/ATF1 in CCS development. In addition, the cellular origins of CCS have not been determined. Here, we generated EWS/ATF1-inducible mice and examined the effects of EWS/ATF1 expression in adult somatic cells. We found that forced expression of EWS/ATF1 resulted in the development of EWS/ATF1-dependent sarcomas in mice. The histology of EWS/ATF1-induced sarcomas resembled that of CCS, and EWS/ATF1-induced tumor cells expressed CCS markers, including S100, SOX10, and MITF. Lineage-tracing experiments indicated that neural crest–derived cells were subject to EWS/ATF1-driven transformation. EWS/ATF1 directly induced Fos in an ERK-independent manner. Treatment of human and EWS/ATF1-induced CCS tumor cells with FOS-targeted siRNA attenuated proliferation. These findings demonstrated that FOS mediates the growth of EWS/ATF1-associated sarcomas and suggest that FOS is a potential therapeutic target in human CCS.

Authors

Kazunari Yamada, Takatoshi Ohno, Hitomi Aoki, Katsunori Semi, Akira Watanabe, Hiroshi Moritake, Shunichi Shiozawa, Takahiro Kunisada, Yukiko Kobayashi, Junya Toguchida, Katsuji Shimizu, Akira Hara, Yasuhiro Yamada

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Figure 1

Inducible expression of EWS/ATF1.

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Inducible expression of EWS/ATF1. (A) Schematic of the doxycycline-ind...
(A) Schematic of the doxycycline-inducible EWS/ATF1 alleles. (B) EWS/ATF1 expression in ES cells, detected by RT-PCR, after exposure to doxycycline for 12 hours. (C) EWS/ATF1 expression in ES cells, detected by Western blot, after exposure to doxycycline for 24 hours. (D) Dose-dependent induction of EWS/ATF1 protein in EWS/ATF1-inducible ES cells by doxycycline. ES cells were exposed to doxycycline concentrations up to 2 μg/ml for 24 hours. Western blot analysis was performed using an anti-HA antibody. (E) Dose-dependent doxycycline induction of EWS/ATF1 mRNA in EWS/ATF1-inducible MEFs. MEFs were exposed to different concentrations of doxycycline for 24 hours. Transcript levels were normalized to β-actin. Data are mean ± SD (n = 3). (F) EWS/ATF1 expression suppressed MEF growth. Cell viability was determined by WST-8 assay. Data are mean ± SD (n = 4). Control MEFs (rtTA) and EWS/ATF1-inducible MEFs (E/A) were derived from heterozygous Rosa26::M2rtTA and Col1A1::tetO-EWS/ATF1 mice, respectively. ***P < 0.001 vs. MEF (rtTA) Dox 0.0 μg/ml, MEF (rtTA) Dox 2.0 μg/ml, and MEF (E/A) Dox 0.0 μg/ml.