Abstract
Thyroid-stimulating-hormone-alpha (TSH-α) is the common subunit of the heterodimeric hormone TSH and also of other glycoprotein hormones. Although both expression and promoter-methylation profiles of the gene have been observed in the pituitary gland and placenta, no observation has been reported in the thyroid gland. We examined TSH-α expression in normal and cancer thyroid tissues. Keal-time RT-PCR and immunohistochemistry indicated that TSH-α was repressed in normal tissues while activated in cancer tissues. To identify the epigenetic mechanism of upregulation of TSH-α, the methylation status of the seven CpG sites in the TSH-α promoter was examined in sixty thyroid cancer tissues. Two CpG sites showed remarkably higher levels of methylation in cancer (46 and 45%) than in normal tissues (24 and 23%) (p=0.010 and 0.003). These findings indicate that TSH-α is expressed in the thyroid cancer tissue per se and that its expression can be affected by promoter methylation.
Original language | English |
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Pages (from-to) | 341-347 |
Number of pages | 7 |
Journal | Genes and Genomics |
Volume | 31 |
Issue number | 5 |
DOIs | |
State | Published - Oct 2009 |
Keywords
- CpG islands
- Epigenetics
- Methylation
- Thyroid cancer
- Thyroid-stimulating hormone