Glucocorticoid receptor subunit gene expression in thyroid gland and adenomas

Abstract

The present study was undertaken to investigate whether the glucocorticoid receptor –α (GR-α) and –β (GR-β) mRNA may be expressed in thyroid gland. Ten normal thyroid gland and 14 follicular adenomas were studied using a real-time fluorescent quantitative RT-PCR (FQ-RT-PCR) method. The results demonstrated that there was a lower expression of GR-α mRNA (×10⁶ GR-α cDNA copies/µg total RNA) in thyroid adenoma (1.27±0.26) than that in normal thyroid gland (3.53±1.22) (p < 0.001). The expression of GR-β mRNA was lower in all the thyroid tissues. Of note, there was a significant difference in GR-β mRNA expression (×10⁴ GR-β cDNA copies/µg total RNA) between thyroid adenoma (80.8±13.9) and thyroid gland (1.78±0.59) (p < 0.001). The GR-α/GR-β ratios in thyroid adenoma and normal thyroid gland were 1.67±0.68 and 207.57±84.41 respectively (p < 0.001). These results revealed, for the first time, that both GR-α and GR-β mRNA expression were detectable in both thyroid gland and adenomas tissues. We therefore conclude that down-regulation of GR-α and up-regulation of GR-β mRNA expression may play an important role in the thyroid adenomas.