Progesterone Upregulates Gene Expression in Normal Human Thyroid Follicular Cells

Abstract

Thyroid cancer and thyroid nodules are more prevalent in women than men, so female sex hormones may have an etiological role in these conditions. There are no data about direct effects of progesterone on thyroid cells, so the aim of the present study was to evaluate progesterone effects in the sodium-iodide symporterNIS, thyroglobulinTG, thyroperoxidaseTPO, andKI-67genes expression, in normal thyroid follicular cells, derived from human tissue.NIS,TG,TPO, andKI-67mRNA expression increased significantly after TSH 20 μUI/mL, respectively: 2.08 times,P<0.0001; 2.39 times,P=0.01; 1.58 times,P=0.0003; and 1.87 times,P<0.0001. In thyroid cells treated with 20 μUI/mL TSH plus 10 nM progesterone, RNA expression ofNIS,TG, andKI-67genes increased, respectively: 1.78 times,P<0.0001; 1.75 times,P=0.037; and 1.95 times,P<0.0001, andTPOmRNA expression also increased, though not significantly (1.77 times,P=0.069). These effects were abolished by mifepristone, an antagonist of progesterone receptor, suggesting that genes involved in thyroid cell function and proliferation are upregulated by progesterone. This work provides evidence that progesterone has a direct effect on thyroid cells, upregulating genes involved in thyroid function and growth.