An integrated chemical biology approach identifies specific vulnerability of Ewing's sarcoma to combined inhibition of Aurora kinases A and B

Mol Cancer Ther. 2011 Oct;10(10):1846-56. doi: 10.1158/1535-7163.MCT-11-0100. Epub 2011 Jul 18.

Abstract

Ewing's sarcoma is a pediatric cancer of the bone that is characterized by the expression of the chimeric transcription factor EWS-FLI1 that confers a highly malignant phenotype and results from the chromosomal translocation t(11;22)(q24;q12). Poor overall survival and pronounced long-term side effects associated with traditional chemotherapy necessitate the development of novel, targeted, therapeutic strategies. We therefore conducted a focused viability screen with 200 small molecule kinase inhibitors in 2 different Ewing's sarcoma cell lines. This resulted in the identification of several potential molecular intervention points. Most notably, tozasertib (VX-680, MK-0457) displayed unique nanomolar efficacy, which extended to other cell lines, but was specific for Ewing's sarcoma. Furthermore, tozasertib showed strong synergies with the chemotherapeutic drugs etoposide and doxorubicin, the current standard agents for Ewing's sarcoma. To identify the relevant targets underlying the specific vulnerability toward tozasertib, we determined its cellular target profile by chemical proteomics. We identified 20 known and unknown serine/threonine and tyrosine protein kinase targets. Additional target deconvolution and functional validation by RNAi showed simultaneous inhibition of Aurora kinases A and B to be responsible for the observed tozasertib sensitivity, thereby revealing a new mechanism for targeting Ewing's sarcoma. We further corroborated our cellular observations with xenograft mouse models. In summary, the multilayered chemical biology approach presented here identified a specific vulnerability of Ewing's sarcoma to concomitant inhibition of Aurora kinases A and B by tozasertib and danusertib, which has the potential to become a new therapeutic option.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Aurora Kinases
  • Bone Neoplasms / drug therapy*
  • Bone Neoplasms / enzymology
  • Bone Neoplasms / genetics
  • Bone Neoplasms / pathology
  • Cell Cycle / drug effects
  • Down-Regulation / drug effects
  • Drug Synergism
  • Gene Knockdown Techniques
  • Humans
  • Mice
  • Mice, SCID
  • Oncogene Proteins, Fusion / biosynthesis
  • Oncogene Proteins, Fusion / genetics
  • Piperazines / pharmacology
  • Protein Kinase Inhibitors / pharmacology*
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein-Serine-Threonine Kinases / genetics
  • Proto-Oncogene Protein c-fli-1 / biosynthesis
  • Proto-Oncogene Protein c-fli-1 / genetics
  • RNA Interference
  • RNA-Binding Protein EWS / biosynthesis
  • RNA-Binding Protein EWS / genetics
  • Random Allocation
  • Sarcoma, Ewing / drug therapy*
  • Sarcoma, Ewing / enzymology
  • Sarcoma, Ewing / genetics
  • Sarcoma, Ewing / pathology
  • Xenograft Model Antitumor Assays

Substances

  • EWS-FLI fusion protein
  • Oncogene Proteins, Fusion
  • Piperazines
  • Protein Kinase Inhibitors
  • Proto-Oncogene Protein c-fli-1
  • RNA-Binding Protein EWS
  • VX680
  • Aurora Kinases
  • Protein-Serine-Threonine Kinases