Epidermal growth factor receptors in human tumors of the central nervous system.
Epidermal growth factor receptors (EGF-R) have been measured in human tumors of the Central Nervous System (CNS) by 125I EGF ligand binding. High affinity receptors (Ka congruent to 1 x 10(9) M-1) were detected in nearly all individual specimens of meningiomas and tumors of glial origin (astrocytomas, glioblastomas). The phosphotyrosine kinase activity associated with the EGF-R was evaluated by measuring the incorporation of gamma 32P-ATP, after immunoprecipitation of the receptor with the monoclonal antibody EGFRI. A good relationship was observed between the EGF-binding capacity and the autophosphorylation of the receptor, indicating that in most cases functional molecules of EGF-R were expressed on the tumor membranes. In the group of meningiomas, no relationship could be established between the EGF-R level and the histopathology of the tumors. Astrocytomas exemplify a progression of malignancy, from benign (low grade astrocytomas) towards an increased malignant phenotype (glioblastomas). In this group, our observations indicate a positive relationship between the EGF-R level and phosphokinase activity and the degree of malignancy.
Baugnet-Mahieu
L
L
Department of Radioprotection, CEN-SCK, Mol, Belgium.
Lemaire
M
M
Brotchi
J
J
Levivier
M
M
Born
J
J
Gilles
J
J
Valkenaers-Michaux
A
A
Vangheel
V
V
D001932:Brain Neoplasms / Q000737:chemistry*; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D010766:Phosphorylation; D014443:Tyrosine / Q000378:metabolism
D014443:Tyrosine; D004815:Epidermal Growth Factor; D066246:ErbB Receptors