T4 and integrin receptors

[Forestgarden]

I've come across integrin receptors mentioned in a few papers recently where t4 seems to have some activity (generally its assumed t4 is not an active hormone), so was interested to read the following paper. This is yet another good reason for t3/t4 combination treatment.

"Preliminary clinical evidence indicates that lowering of systemic T4 levels and maintaining normal metabolic state with T3 (euthyroid hypothyroxinemia) (15) slows growth of multiple types of solid tumors. Clinical hypothyroidism has been shown in multiple reports specifically to slow the clinical course of renal cell carcinoma (16), breast cancer (17), glioblastoma (18), and head-and-neck cancers (19). Such evidence confirms that T3 has little activity at the integrin receptor for thyroid hormone analogues."

"The recognition of the thyroid hormone receptor for T4 on integrin αvβ3 and its contribution to differentiated thyroid cancer cell proliferation raises the possibility that when TSH suppression is sometimes ineffective in thyroid tumor management, the tumor is manifesting T4-dependence, rather than TSH-dependence"

frontiersin.org/articles/10...

[jimh111]

This is a very serious problem, my best guess is that combination therapy with a little liothyronine would save about 1,000 thyroid patient lives a year (assuming 3% of people are on levothyroxine). If you look at my profile you will find a number of posts on this subject including this one healthunlocked.com/thyroidu... . Thyroxine acting on this integrin receptor also contributes to cardiac deaths.

The bottom line is that combination therapy on an equivalent dose basis is safer than levothyroxine monotherapy.