Endocrine Abstracts

Acetylation of DNA can result in gene silencing. In the thyroid such phenomena can lead to the loss of ability to accumulate radioiodide. The aim of this study was to examine the effects on the rat thyroid cell line FRTL-5 and human thyroid follicular cancer cell line FTC-133 of Trichostatin A (TSA), a histone deactylase inhibitor. A concentration of TSA was selected using MTT cell viability assays for use in uptake, efflux and expression studies. Cells were incubated with TSA...

Epigenetic phenomena such as methylation or acetylation of DNA can result in transcriptional inactivation and gene silencing. In the thyroid such phenomena can bring about the loss of ability to accumulate iodide as a result of methylation of CpG islands in human sodium iodide symporter (NIS) and Pendrin (PDS) DNA, limiting the ability to utilise radioiodide therapy. This study examines the effects of Trichostatin A (TSA) a histone deacetylase (HDAC) inhibitor on a rat thyroid...

Uptake of ingested iodide (I-) in the thyroid is achieved through an active transport system, the sodium iodide symporter (NIS). The gland has the ability to accumulate I- from the bloodstream by a factor of 20-40. Seaweeds, which in vivo bear the same relationship to seawater, as does the thyroid to the bloodstream, have a dramatically more efficient I- uptake system, accumulating I- from seawater by a factor of anything up to 1 mil...

Seaweed consumption results in high levels of iodine intake in Asian populations and influences the presentation of thyroid and perhaps extrathyroidal disorders. The relationship of seawater to seaweed is analogous to that between the bloodstream and the thyroid. However, seaweed has a dramatically more efficient uptake system than the thyroid, concentrating iodide from seawater by a factor of up to 106 compared to 40-50 for the thyroid. The ability of seaweeds to b...

Synthesis of thyroid hormones by the fetal thyroid requires the passage of iodide through the placenta. In the thyroid active iodide transport is facilitated by three transporters, the sodium iodide symporter (NIS), Pendrin (PDS) and the recently described the human apical iodide transporter (hAIT). Simultaneous expression of all three transporters appears to be thyroid restricted and although extrathyroidal expression of individual transporters has been reported, relatively l...