Thyroid hormone regulation of epidermal growth factor receptor levels in mouse mammary glands

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-119-2-580· OSTI ID:5013379

Vonderhaar, B K; Tang, E; Lyster, R R; Nascimento, M C

The specific binding of iodinated epidermal growth factor ((/sup 125/I)iodo-EGF) to membranes prepared from the mammary glands and spontaneous breast tumors of euthyroid and hypothyroid mice was measured in order to determine whether thyroid hormones regulate the EGF receptor levels in vivo. Membranes from hypothyroid mammary glands of mice at various developmental ages bound 50-65% less EGF than those of age-matched euthyroid controls. Treatment of hypothyroid mice with L-T4 before killing restored binding to the euthyroid control level. Spontaneous breast tumors arising in hypothyroid mice also bound 30-40% less EGF than tumors from euthyroid animals even after in vitro desaturation of the membranes of endogenous growth factors with 3 M MgCl2 treatment. The decrease in binding in hypothyroid membranes was due to a decrease in the number of binding sites, not to a change in affinity of the growth factor for its receptor, as determined by Scatchard analysis of the binding data. Both euthyroid and hypothyroid membranes bound EGF primarily to a single class of high affinity sites (dissociation constant (Kd) = 0.7-1.8 nM). Euthyroid membranes bound 28.4 +/- (SE) 0.6 fmol/mg protein, whereas hypothyroid membranes bound 15.5 +/- 1.0 fmol/mg protein. These data indicate that EGF receptor levels in normal mammary glands and spontaneous breast tumors in mice are subject to regulation by thyroid status.

• Research Organization: National Cancer Institute, Bethesda, MD
• OSTI ID: 5013379
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 2; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL FUNCTIONS
BODY
CARBOXYLIC ACIDS
CARCINOMAS
CHEMICAL BONDS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE DISEASES
EPIDERMIS
EPITHELIUM
FUNCTIONS
GLANDS
GROWTH
HORMONES
HYPOTHYROIDISM
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIVER
MAMMALS
MAMMARY GLANDS
MEMBRANE PROTEINS
MICE
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANS
PEPTIDE HORMONES
PROTEINS
RADIOISOTOPES
RECEPTORS
RODENTS
SKIN
THYROID HORMONES
THYROXINE
TISSUES
TRACER TECHNIQUES
VERTEBRATES