Thyroid hormone as a regulator of tumor induced angiogenesis.

Thyroid hormones (TH) - 3,5,3'-triiodo-L-thyronine (T₃) and l-thyroxine (T₄) - are important regulators of differentiation, growth, metabolism, and physiological function in most tissues. TH have been also implicated in cellular transformation, tumorigenesis and metastasis, assuming particular importance in tumor induced angiogenesis. TH-induced angiogenesis is thought to be initiated at integrin αvβ3 membrane receptor mainly through T₄ binding. The reduction of TH in circulation or the inhibition of TH actions at the integrin αvβ3 receptor would consequently produce a reduction on the proliferative and angiogenic TH effects. Therefore, targeting TH actions could be an alternative adjuvant therapy against cancer proliferation and angiogenesis. Copyright Â