Human glioblastoma cell lines have neuropeptide receptors for bombesin/gastrin-releasing peptide.
Bombesin/gastrin-releasing peptide receptors were characterized in human glioblastoma cell lines. [125I]Gastrin-releasing peptide or ([125I]Tyr4)bombesin bound with high affinity to these cell lines. Binding to cell line U-118 was time dependent, reversible, and specific. ([125I]Tyr4)Bombesin bound with high affinity (Kd = 1.6 nM) to a single class of sites (Bmax = 30,000/cell). The C-terminal of bombesin- or gastrin-releasing peptide was essential for high-affinity binding. Bombesin- or gastrin-releasing peptide elevated the cytosolic Ca2+ levels in a dose-dependent manner. Because gastrin-releasing peptide, but not gastrin-releasing peptide, increased the cytosolic Ca2+ levels, the C-terminal but not the N-terminal of GRP is essential for biological activity. These data indicate that biologically active bombesin receptors are present in human glioblastoma cell lines.
Moody
T W
TW
Department of Biochemistry, George Washington University School of Medicine, Washington, DC 20037.
Mahmoud
S
S
Staley
J
J
Naldini
L
L
Cirillo
D
D
South
V
V
Felder
S
S
Kris
R
R
D001667:Binding, Competitive; D001839:Bombesin / Q000378:metabolism* / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism; D005910:Glioma; D006801:Humans; D007700:Kinetics; D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism*
D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter; D001839:Bombesin; D002118:Calcium