The genomic breakpoint and chimeric transcripts in the EWSR1-ETV4/E1AF gene fusion in Ewing sarcoma.
Chromosome translocation creates a fusion between the EWSR1 gene and an ETS family gene. The fusion between these two genes is a characteristic feature of Ewing sarcoma. We previously identified a fourth translocation, t(17;22)(q12;q12), in genomic DNA isolated from cells of patients affected with Ewing sarcoma. The discovery of this translocation suggested that there might be a novel EWSR1-ETV4 fusion gene. In the present study, we determined the genomic breakpoint and characterized the chimeric transcript of the EWSR1-ETV4 fusion gene in two t(17;22) Ewing sarcomas. Reverse transcriptase-PCR assay showed an in-frame fusion between the 5'-terminal region of EWSR1 and the 3' end of ETV4 (alias E1AF, PEA3); the chimeric transcript could thus serve as a template for expression of a protein composed of the N-terminal portion of EWSR1 fused to the DNA-binding domain of ETV4. Long PCR and sequence analysis of genomic DNA revealed that either exon 8 or intron 7 of EWSR1 is fused to the same intron of ETV4 in both tumors. Several palindromic oligomer sequences were found close to the breakpoints in both genes. The 159-bp Alu-like sequence was repeated in the breakpoint region of the ETV4 gene. These observations suggest a mechanism of EWSR1-ETV4 gene fusion.
Ishida
S
S
Department of Molecular Biology, Cancer Research Institute, School of Medicine, Sapporo Medical University, Sapporo (Japan).
Yoshida
K
K
Kaneko
Y
Y
Tanaka
Y
Y
Sasaki
Y
Y
Urano
F
F
Umezawa
A
A
Hata
J
J
Fujinaga
K
K
D020087:Alu Elements; D019677:Artificial Gene Fusion; D001483:Base Sequence; D002678:Chimera; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000032:analysis; D015972:Gene Expression Regulation, Neoplastic; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008969:Molecular Sequence Data; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000235:genetics*; D012261:Ribonucleoproteins / Q000235:genetics*; D012512:Sarcoma, Ewing / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014178:Translocation, Genetic
D017931:DNA Primers; D004273:DNA, Neoplasm; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; C065788:transcription factor PEA3