17-AAG Inhibits Synovial Sarcoma Cell Growth in vitro

1
17-AAG Inhibits Synovial Sarcoma Cell Growth in
vitro
Jefferson Terry, Suzanne Liu, Joanna Lubieniecka
and Torsten O. Nielsen Genetic Pathology
Evaluation Centre, Vancouver Coastal Health
Research Institute, and British Columbia Cancer
Agency, University of British Columbia, Canada
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Synovial Sarcoma (SS)

• SS 5-10 of sarcomas
• Typically affects young adults
• 10 year survival 40
• Effective systemic therapy required

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SS gene expression data

• Body segmentation
• Retinoic acid metabolism
• Mesenchymal (incl. nerve) differentiation
• Epithelial differentiation
• Proliferation genes Wnt pathway
• Receptor tyrosine kinases EGFR1, FGFR3

4
Tissue microarray validation of EGFR in synovial
sarcomas 38/42 cases show positive
immuno-staining
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SS model systems

• Cell lines
• Fuji
• (Nojima et al. Acta Pathologica Japonica
  199040(7)486)
• SYO-1
• (Kawai et al. Cancer Letters 2004204105)
• FU-SY
• (Nishio et al., International Journal of Oncology
  20022117)
• Growth models
• Monolayer
• Spheroid

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Gefitinib (Iressa) inhibits monolayer SS growth
at high concentrations
100 ?M gefitinib
50 ?M gefitinib
10 ?M gefitinib
Fuji
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Gefitinib inhibits other tyrosine kinase receptors
Y kinases S-T kinases
HER2 Raf
KDR Mek-1
Flt-1 ERK-2
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17-AAG(17-(Allylamino)-17-demethoxygeldanamycin)

• Modified antibiotic
• Inhibits function of Hsp90
• Protein folding
• Y Kinase turnover (EGFR)
• Presently in phase II clinical trials

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17-AAG inhibits monolayer SS growth
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17-AAG induces apoptosis in monolayer SS
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17-AAG induces apoptosis in SS 3D-spheroids
Control
5x10-6M 17-AAG
PI
PI
Annexin V
Annexin V
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17-AAG induces apoptosis in SS spheroids
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Radicicol inhibits monolayer SS growth
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Mechanism of 17-AAG Tyrosine Kinase Receptors
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Wnt/ß-catenin signaling in synovial sarcoma
549 cases representing 46 mesenchymal tumors (in
press) SS one of only 4 tumor types with high
level nuclear ß-catenin
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Mechanism of 17-AAG ß-catenin
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Conclusions

• Gefitinib inhibits SS growth only at very high
  concentrations
• 17-AAG induces significant apoptosis in SS at
  clinically achievable concentrations
• Spheroid studies imply 17-AAG may prove effective
  in in vivo studies

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Acknowledgements

• This research was funded by
• Terry Fox Foundation
• Michael Smith Foundation for Health Research
• Canadian Institutes for Health Research