EWS-Fli1 up-regulates expression of the Aurora A and Aurora B kinases.
EWS-Fli1, a fusion gene resulting from the chromosomal translocation t(11;22, q24;q12), encodes a transcriptional activator, promotes cellular transformation, and is often found in Ewing sarcoma and primitive neuroectodermal tumor. The Aurora A and Aurora B kinases belong to a highly conserved family of serine/threonine protein kinases, are tightly regulated during the cell cycle, and are overexpressed in many carcinomas. Because the relationship between the Aurora A and/or Aurora B genes and the EWS-Fli1 fusion gene is unknown, we investigated the regulatory mechanism(s) by which Aurora kinases are controlled. Knockdown of EWS-Fli1 by small interfering RNA reduced mRNA levels not only of EWS-Fli1 but also of Aurora A and Aurora B. Luciferase assay using Aurora A and Aurora B promoters showed up-regulated activities compared with those of an empty vector. Experiments with deletion and point mutants showed positive regulatory Ets-binding sites located -84 and -71 bp upstream of the transcription initiation sites in Aurora A and Aurora B, respectively. Moreover, chromatin immunoprecipitation assay revealed that EWS-Fli1 gene products interact with both the Aurora A and Aurora B promoters. These results strongly suggest that the mitotic kinases Aurora A and Aurora B are regulated by EWS-Fli1 fusion protein in Ewing sarcoma cells.
Wakahara
Kazuhiko
K
Department of Orthopaedic Surgery, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, Japan.
Ohno
Takatoshi
T
Kimura
Masashi
M
Masuda
Takahiro
T
Nozawa
Satoshi
S
Dohjima
Taikoh
T
Yamamoto
Takatoshi
T
Nagano
Akihito
A
Kawai
Gou
G
Matsuhashi
Aya
A
Saitoh
Mitsuru
M
Takigami
Iori
I
Okano
Yukio
Y
Shimizu
Katsuji
K
D064107:Aurora Kinase B; D064127:Aurora Kinases; D001859:Bone Neoplasms / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D045744:Cell Line, Tumor; D016384:Consensus Sequence; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D051789:Proto-Oncogene Protein c-fli-1 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D034802:RNA-Binding Protein EWS; D012512:Sarcoma, Ewing / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D014158:Transcription, Genetic / Q000502:physiology
C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D012333:RNA, Messenger; D034802:RNA-Binding Protein EWS; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases