Inhibition of EWS-FLI-1 fusion protein with antisense oligodeoxynucleotides

J Neurooncol. 1997 Jan;31(1-2):9-16. doi: 10.1023/a:1005716926800.


Ewing's sarcoma family of tumors (EFT) contain reciprocal translocations, of which approximately 90% occur between the long arm of chromosomes 11 and 22,t(11;22)(q24;q12) resulting in the formation of chimeric proteins generated by a fusion of the EWS and FLI-1 genes. To determine if EWS-FLI-1 protein is responsible for the Ewing sarcoma phenotype we have used sequence-specific antisense oligodeoxynucleotides (ODN) to block its expression. We have evaluated a series of antisense ODN directed toward the breakpoint region in an effort to prevent translation of the fusion messenger RNA. ODN were first evaluated in a cell-free in vitro translation system. Exogenously added RNase H was found to be required for translation inhibition. ODN that showed complete inhibition of translation were electroporated into TC-32 cells, a EFT cell line. Fusion protein and EWS protein levels were evaluated by Western blot analysis. A 40-60% decrease in the fusion protein was observed in TC-32 cells with antisense ODN directed toward the breakpoint region. Cell viability was reduced with antisense sequences in TC-32 cells but not in a prostate cancer cell line. Since inhibition of t(11:22) gene product is correlated to effects on cell viability reduction of the fusion protein may thus offer insight into the biology of EFT.

MeSH terms

  • Bone Neoplasms / genetics*
  • Cell Division / genetics
  • Cell Survival / genetics
  • Electroporation / standards
  • Gene Expression Regulation, Neoplastic / physiology
  • Genetic Testing
  • Humans
  • Male
  • Oligonucleotides, Antisense / genetics*
  • Prostatic Neoplasms
  • Recombinant Fusion Proteins / genetics
  • Sarcoma, Ewing / genetics*
  • Transcription, Genetic / genetics
  • Translocation, Genetic
  • Tumor Cells, Cultured / cytology
  • Tumor Cells, Cultured / physiology


  • Oligonucleotides, Antisense
  • Recombinant Fusion Proteins