Involvement of Aberrant Glycosylation in Thyroid Cancer

Figure 4

Oligosaccharides involve in the regulation of thyroid function. The production of thyroid hormone by the thyroid gland is regulated by　the hypothalamus and the pituitary gland. Hypothalamic thyrotropin-releasing hormone (TRH) induces the pituitary gland to release thyroid-stimulating hormone (TSH) into the general circulation, whereby it reaches the thyroid gland and stimulates the production and release of thyroid hormone [1]. T4 is the predominant secretory product of the thyroid gland, with peripheral　deiodination of T4 to T3 in the liver and kidneys supplying roughly 80% of the circulating T3. Both circulating T3 and T4 directly inhibit TSH synthesis and are released independently; T4 via its rapid conversion to T3. Circulating T4 and T3 are bound predominantly to serum proteins. FT3 is the metabolically active form of thyroid hormone, whereas protein-bound T3 and T4 may be considered reservoirs of the hormone in equilibrium with the metabolically active free hormone.