TRANSFORMING GROWTH-FACTOR-BETA-1 (TGF-BETA-1) EXPRESSION IN PROLIFERATING THYROID-DISEASE

In order to clarify some of the molecular mechanisms involved in the p athogenesis of thyroid proliferating diseases we have investigated the role of TGF-beta in thyroid carcinoma, adenoma and multinodular goite r. TGF-beta 1 expression studies were carried out in surgically remove d thyroid tissue isolated from 15 patients affected by multinodular go iter, 4 patients affected by papillary carcinoma and 4 patients affect ed by follicular adenoma. TGF-beta 1 gene expression, evaluated by Nor thern analysis, dramatically increased in malignant proliferating thyr oid disease and decreased drasticly in multinodular goiter patients wi th respect to normal thyroid. Immunocytochemical analysis demonstrated that TGF-beta 1 is produced by an autocrine mechanism in the carcinom a and in the benign thyroid disease (multinodular goiter), whereas TGF -beta seems to be produced in adenoma tissues in both an autocrine and a paracrine fashion. This feature further supports the hypothesis tha t TGF-beta may contribute to regulation of thyrocyte growth and differ entiation.