Immunohistochemical Analysis of Platelet-derived Growth Factor Receptor-α, -β, c-kit, c-abl, and Arg Proteins in Glioblastoma: Possible Implications for Patient Selection for Imatinib Mesylate Therapy

Inhibition of tyrosine kinase (TK) receptors by synthetic small molecules has become a promising new therapy option in oncology. The TK inhibitor imatinib mesylate selectively targets PDGFR-α, -β, c-kit, c-abl and arg and has proven successful in the treatment of chronic myeloid leukaemia. In recurrent glioblastoma, phase II therapy trials using imatinib mesylate have been initiated. As only a fraction of patients seems to benefit from imatinib mesylate therapy and due to potential side effects and high costs of imatinib mesylate therapy, selection of the right patients is important. The goal of our study was to assess systematically immunohistochemical expression of the major TKs targeted by imatinib mesylate in glioblastoma, as expression of these factors could be used to select patients for imatinib mesylate therapy.