Epidermal growth factor receptors and adenylate cyclase activity in human thyroid tissues

Abstract

Thyroid stimulating hormone (TSH) and epidermal growth factor (EGF) are growth factors for some thyroid cells in cultures. We have previously found more EGF receptors in neoplastic human thyroid tissues than in normal thyroid tissues. We have also found a higher TSH-stimulated adenylate cyclase (AC) activity in neoplastic human thyroid tissues than in normal thyroid tissues. To clarify the relationship between the effect of EGF and TSH on thyroid tissue, we measured the binding of EGF and TSH and the basal, TSH-stimulated and forskolin-stimulated adenylate cyclase activity in 49 normal, hyperplastic and neoplastic human thyroid tissues (5 normal, 2 Hashimoto thyroiditis, 5 Graves' disease, 14 multinodular goiters, 9 follicular adenomas, 5 follicular carcinomas, 8 papillary carcinomas, and 1 undifferentiated carcinoma). Specific binding of EGF and TSH were measured by radioreceptor assays using competitive inhibition of radio-labeled ligand by unlabeled ligand. Basal, maximally (300 mU/ml) TSH-stimulated, and maximally (100 mM) forskolin-stimulated adenylate cyclase activities were also measured in the same membrane particulate fractions from the thyroid tissues. We found: neoplastic thyroid tissues bind more labeled EGF than nonneoplastic thyroid tissues; follicular adenomas and carcinomas have higher EGF binding than other thyroid tissues; a weak but significant correlation between specific EGF binding and specific TSH binding, and between specific EGF binding and TSH-stimulated adenylate cyclase activity of the thyroid membrane preparations. These findings are consistent with the hypothesis that TSH stimulates an increase in thyroid EGF receptors by increasing intracellular cAMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidermal Growth Factor Receptor (EGFR) Is Overexpressed in Anaplastic Thyroid Cancer, and the EGFR Inhibitor Gefitinib Inhibits the Growth of Anaplastic Thyroid Cancer

“…In preclinical studies, EGF has been shown to stimulate follicular cell proliferation and to enhance the migration and invasiveness of papillary thyroid cancer (9 -11). The medical literature generally supports the concept that EGFR, although expressed at higher levels in anaplastic and papillary cancers than in normal thyroid tissue, is present in all of the thyroid tissues, but the data in different studies often vary widely (9,(12)(13)(14)(15)(16)(17). In an in vitro study by Bergstrom et al (18), EGFR was expressed in all six ATC cell lines examined, and constitutive phosphorylation of EGFR was found in three of the six cell lines tested.…”

Protein expression of VEGF, IGF-1 and FGF in retroocular connective tissues and clinical correlation in Graves' ophthalmopathy

“…There were other authors who found that TSH stimulates an increase in thyroid EGF receptors by increasing intracellular cAMP (22) . VEGF can induce angiogenesis in a complex way, which involves selective division of endothelial cells, vascular membrane degradation surrounded by cellular matrix and migration of endothelial cells (23) .…”

Expression of the estrogen receptor α, progesterone receptor and epidermal growth factor receptor in papillary thyroid carcinoma tissues

“…Numerous studies have reported that the overexpression of EGFR in an anaplastic, undifferentiated subtype of PTC is associated with a high mortality rate (28)(29)(30)(31). However, little is known about the value of EGFR expression in predicting the prognosis of thyroid carcinoma.…”