EWS/FLI1 up regulates mE2-C, a cyclin-selective ubiquitin conjugating enzyme involved in cyclin B destruction.
The EWS/FLI1 fusion gene found in Ewing's sarcoma and primitive neuroectodermal tumor, is able to transform certain cell lines by acting as an aberrant transcription factor. The ability of EWS/FLI1 to modulate gene expression in cells transformed and resistant to transformation by EWS/FLI1, was assessed by Representational Difference Analysis (RDA). We found that the cyclin selective ubiquitin conjugase murine E2-C, was up regulated in NIH3T3 cells transformed by EWS/FLI1 but not in a nontransformed NIH3T3 clone expressing EWS/FLI1. We also found that mE2-C is upregulated in NIH3T3 cells transformed by other genes including activated cdc42, v-ABL and c-myc. We demonstrated that expression of mE2-C in both the EWS/FLI1 transformed and parent NIH3T3 lines varies with the cell cycle. Finally, dominant-negative mE2-C, created by changing a catalytic cysteine to serine, inhibits the in vitro ubiquitination and degradation of cyclin B in human HeLa cell extracts. These data suggest that part of the biologic effect of EWS/FLI1 could be to transcriptionally modulate genes involved in cell cycle regulation.
Arvand
A
A
Department of Experimental Pathology/Laboratory Medicine, University of California, Los Angeles, USA.
Bastians
H
H
Welford
S M
SM
Thompson
A D
AD
Ruderman
J V
JV
Denny
C T
CT
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis*; D002453:Cell Cycle; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic; D002474:Cell-Free System; D019926:Cyclin B / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D008025:Ligases; D051379:Mice; D008969:Molecular Sequence Data; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D044763:Ubiquitin-Conjugating Enzymes; D015854:Up-Regulation
D002352:Carrier Proteins; D019926:Cyclin B; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors; C046288:ubiquitin carrier proteins; D044763:Ubiquitin-Conjugating Enzymes; D008025:Ligases