Insulin-like growth factor type I biology and targeting in malignant gliomas

Growth factors such as insulin-like growth factor type I (IGF-I), epidermal growth factor (EGF), vascular-endothelial growth factor (VEGF) and transforming growth factor β (TGF-β) are present during the development of the CNS. When they reappear in the mature brain they are overexpressed in neoplastic glia, participating in the development of the most common human brain malignant tumor, glioblastoma multiforme, which is invariably fatal. Progress in treatment of this disease involves an increase in median survival from 8 to 11 months to an average of 15 months, rarely to 18 months. We do not know any therapy, which can make a complete stop of this neoplasm. To inhibit this process various anti-growth factor therapies have been proposed.