[Expression of insulin-like growth factor I receptors in human brain tumors: comparison with epidermal growth factor...

By using quantitative autoradiographic techniques, receptors for insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) were analyzed in 13 samples of human brain tumors (4 low grade astrocytomas, 7 glioblastomas, 1 anaplastic ependymoma and 1 medulloblastoma). High number of specific binding sites for IGF-I and EGF were homogeneously present in tissue sections derived from glioblastoma. In low grade astrocytoma, relatively high numbers of binding site for EGF were observed, but there was no significant difference in concentrations of IGF-I binding sites between tumors and control cortex. In medulloblastoma, only IGF-I binding sites were present. These observations might indicate that both IGF-I and EGF are involved in the growth modulation of human gliomas possibly through paracrine or autocrine mechanisms. Antagonists to growth factors or monoclonal antibody against those receptors could have the way for therapeutic application for gliomas.