EGF and TGF-β1 Effects on Thyroid Function

الملخص EN

Normal epithelial thyroid cells in culture are inhibited by TGF-β1.

Instead, transformed thyroid cell lines are frequently resistant to its growth inhibitory effect.

Loss of TGF-β responsiveness could be due to a reduced expression of TGF-β receptors, as shown in transformed rat thyroid cell lines and in human thyroid tumors, or to alterations of other genes controlling TGF-β signal transduction pathway.

However, in thyroid neoplasia, a complex pattern of alterations occurring during transformation and progression has been identified.

Functionally, TGF-β1 acts as a tumor suppressor in the early stage of transformation or as a tumor promoter in advanced cancer.

This peculiar pleiotropic behaviour of TGF-β may result from cross-talk with signalling pathways mediated by other growth factors, among which EGF-like ligands play an important role.

This paper reports evidences on TGF-β1 and EGF systems in thyroid tumors and on the cross-talk between these growth factors in thyroid cancer.