Abstract
Chondrosarcomas are notorious for their resistance to conventional chemo- and radiotherapy, indicating there are no curative treatment possibilities for patients with inoperable or metastatic disease. We therefore explored the existence of molecular targets for systemic treatment of chondrosarcoma using kinome profiling.
Peptide array was performed for 4 chondrosarcoma cell lines and 9 primary chondrosarcoma cultures. Acitivity of kinases was verified using immunoblot and active Src- and PDGFR signaling were further explored using imatinib and dasatinib on chondrosarcoma cell lines and primary cultures.
The AKT1/GSK3B pathway was clearly active in chondrosarcoma. In addition, the PDGFR pathway and the Src kinase family were active. PDGFR and Src kinases can be inhibited by imatinib and dasatinib, respectively. While imatinib did not show any effect on chondrosarcoma cell cultures, dasatinib showed a decrease in cell viability at nanomolar concentrations in 3 out of 5 chondrosarcoma cultures. Whereas inhibition of phosphorylated Src (Y419) was found both in responsive and non-responsive cells, caspase-3 related apoptosis was found only in cell line GIST882, suggesting that the mechanism of decreased cell viability in chondrosarcoma by dasatinib is caspase-3 independent.
In conclusion, using kinome profiling we found the Src pathway to be active in chondrosarcoma. Moreover, in the chondrosarcoma cell lines and primary cultures we showed that the inhibitor of the Src pathway, dasatinib, may provide a potential therapeutic benefit for chondrosarcoma patients which are not eligible for surgery.
Correspondence should be addressed to Professor Stefan Bielack, Olgahospital, Klinikum Stuttgart, Bismarkstrasse 8, D-70176 Stuttgart, Germany. Email: s.bielack@klinikum_stuttgart.de
