Elevated epidermal growth factor receptor binding in plutonium-induced lung tumors from dogs.
The objective of this study is to examine and characterize epidermal growth factor receptor (EGF-R) binding in inhaled plutonium-induced canine lung-tumor tissue and to compare it with that in normal canine lung tissue. Crude membrane preparations from normal and lung-tumor tissue from beagle dogs were examined in a radioreceptor assay, using 125I-labeled epidermal growth factor (EGF) as a ligand. Specific EGF receptor binding was determined in the presence of excess unlabeled EGF. We have examined EGF receptor binding in eight lung-tumor samples obtained from six dogs. Epidermal growth factor receptor binding was significantly greater in lung-tumor samples (31.38%) compared with that in normal lung tissue (3.76%). Scatchard plot analysis from the displacement assay revealed that there was no statistical difference in the binding affinity but significantly higher concentration of EGF-R sites in the lung-tumor tissue (619 fmol/mg) than in normal lung tissue (53 fmol/mg). The increase in EGF-R number in plutonium-induced dog lung tumors does not seem to correlate with increase in the initial lung burden exposure to plutonium. Our results demonstrate that there is a significant increase in EGF-R binding in inhaled plutonium-induced dog lung tumors.
Leung
F C
FC
Biology and Chemistry Department, Pacific Northwest Laboratory, Richland, Washington 99352.
Bohn
L R
LR
Dagle
G E
GE
D000231:Adenocarcinoma, Papillary / Q000378:metabolism*; D000280:Administration, Inhalation; D000818:Animals; D001667:Binding, Competitive; D002283:Carcinoma, Bronchogenic / Q000378:metabolism*; D004285:Dogs; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D008175:Lung Neoplasms / Q000209:etiology / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D009381:Neoplasms, Radiation-Induced; D011005:Plutonium; D011869:Radioligand Assay
D008565:Membrane Proteins; D011005:Plutonium; D004815:Epidermal Growth Factor; D066246:ErbB Receptors