TYROSINE KINASE - IMPLICATIONS IN TUMORIG ENESIS AND NEW AVENUES FOR CANCER-TREATMENT

The tyrosine kinase family includes growth factor receptor and cytopla smic enzymes. It plays a key role in normal cell division and abnormal cell proliferation and differentiation. The most common tyrosine kina ses are the epidermal-growth factor (EGFR) and platelet-derived growth factor (PDGF) receptors, and a chromosome Philadelphia product, the B cr-abl oncogene. Many studies have attempted to correlate clinical evo lution of tumors with tyrosine kinase expression. However, clinical ap plication of these new pronostic factors has not yet been demonstrated . More recently, tyrosine-phosphorylation inhibitors (tyrphostin) have been developed in phase I studies. Results that were obtained show so me objective responses in patients with glioblastoma and polymetastic cancer. Another approach to block tyrosine kinase expression is the us e of monoclonal antibodies. Trials using such antibodies have shown in teresting preliminary results. (C) 1998, Elsevier, Paris.