The oncogenic TLS-ERG fusion protein exerts different effects in hematopoietic cells and fibroblasts.
The oncogenic TLS-ERG fusion protein is found in human myeloid leukemia and Ewing's sarcoma as a result of specific chromosomal translocation. To unveil the potential mechanism(s) underlying cellular transformation, we have investigated the effects of TLS-ERG on both gene transcription and RNA splicing. Here we show that the TLS protein forms complexes with RNA polymerase II (Pol II) and the serine-arginine family of splicing factors in vivo. Deletion analysis of TLS-ERG in both mouse L-G myeloid progenitor cells and NIH 3T3 fibroblasts revealed that the RNA Pol II-interacting domain of TLS-ERG resides within the first 173 amino acids. While TLS-ERG repressed expression of the luciferase reporter gene driven by glycoprotein IX promoter in L-G cells but not in NIH 3T3 cells, the fusion protein was able to affect splicing of the E1A reporter in NIH 3T3 cells but not in L-G cells. To identify potential target genes of TLS-ERG, the fusion protein and its mutants were stably expressed in both L-G and NIH 3T3 cells through retroviral transduction. Microarray analysis of RNA samples from these cells showed that TLS-ERG activates two different sets of genes sharing little similarity in the two cell lines. Taken together, these results suggest that the oncogenic TLS-ERG fusion protein transforms hematopoietic cells and fibroblasts via different pathways.
Zou
Junhui
J
Department of Orthopedics, University of Washington, Seattle 98195, USA.
Ichikawa
Hitoshi
H
Blackburn
Michael L
ML
Hu
Hsien-Ming
HM
Zielinska-Kwiatkowska
Anna
A
Mei
Qi
Q
Roth
Gerald J
GJ
Chansky
Howard A
HA
Yang
Liu
L
D017500:Adenovirus E1A Proteins / Q000235:genetics; D000818:Animals; D005347:Fibroblasts / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D020411:Oligonucleotide Array Sequence Analysis; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000502:physiology*; D012319:RNA Polymerase II / Q000378:metabolism; D012326:RNA Splicing; D034702:RNA-Binding Protein FUS / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017384:Sequence Deletion
D017500:Adenovirus E1A Proteins; D015514:Oncogene Proteins, Fusion; D034702:RNA-Binding Protein FUS; C107302:TLS-ERG fusion protein, human; D012319:RNA Polymerase II