Human malignant thyroid tumors displayed reduced levels of transforming growth factor beta receptor type II messenger RNA and protein.
Transforming growth factor beta (TGF-beta) is a physiological regulator of thyroid epithelial cell growth and differentiation. This factor signals through a heteromeric complex composed of type I (TGF-beta receptor type I) and type II [TGF-beta receptor type II (TbetaRII)] receptors. Loss of TbetaRII expression has been related to resistance to TGF-beta inhibition of cell proliferation. In the present work, we analyzed the TbetaRII expression in a series of human thyroid tumors, from benign lesions (adenomas) to neoplastic lesions of increasing aggressiveness (papillary and follicular carcinomas) up to the extremely aggressive anaplastic tumors. Results obtained indicated a clear reduced expression of TbetaRII mRNA only in the group of thyroid carcinomas when compared with their relative normal tissues. Immunohistochemical analyses with specific anti-TbetaRII antibodies confirm these observations. These data indicate that loss of expression of TbetaRII can contribute to thyroid cancer progression, inducing cancer cells to escape the growth-inhibitory effect of TGF-beta.
Lazzereschi
D
D
Dipartimento di Medicina Sperimentale, Università La Sapienza, Rome, Italy.
Ranieri
A
A
Mincione
G
G
Taccogna
S
S
Nardi
F
F
Colletta
G
G
D018263:Adenocarcinoma, Follicular / Q000378:metabolism*; D000328:Adult; D000368:Aged; D015152:Blotting, Northern; D002291:Carcinoma, Papillary / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger / Q000378:metabolism*; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000096:biosynthesis / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000648:ultrastructure*; D016212:Transforming Growth Factor beta / Q000494:pharmacology / Q000502:physiology
D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II