| Abstrakt: |
OBJECTIVES An orphan nuclear receptor, DAX-1, is known to be involved in the development and differentiation of anterior pituitary cells. The present study aimed to examine 1) whether DAX-1 is expressed in human pituitary adenomas, and 2) if it is expressed, what types of adenoma express the factor. MATERIALS AND METHODS Adenoma tissues examined included 18 clinically non-functioning adenomas, 14 GH-secreting adenomas and 7 PRL-secreting adenomas. The expression of the following genes were tested by reverse transcription-polymerase chain reaction (RT-PCR): DAX-1, Adrenal-4-binding protein/steroidogenic factor-1 (Ad4BP/SF-1), Pit-1, LHβ, FSHβ, gonadotrophin-releasing hormone receptor (GnRH-R), GH, PRL, and TSHβ, as well as β-actin as a control. RESULTS Eleven clinically non-functioning adenomas expressed DAX-1, 10 of which also expressed Ad4BP/SF-1. Nine out of the 11 DAX-1-expressing adenomas also expressed LHβ, FSHβ and GnRH-R as well, indicating that these adenomas possessed gonadotrophic properties. Nine clinically non-functioning adenomas expressed Pit-1 as well as GH, PRL and/or TSHβ, thus having somatomammotrophic or thyrotrophic properties, 3 of which overlapped with the above DAX-1-expressing adenomas. One non-functioning adenoma expressed Ad4BP/SF1 and FSHβ but not DAX-1, and another one expressed DAX-1 and Ad4BP/SF-1 with PRL. On the other hand, all GH-secreting and PRL-secreting adenomas expressed Pit-1 and GH and/or PRL, but neither DAX-1 nor Ad4BP/SF-1. CONCLUSIONS The results shown here indicate that DAX-1 is expressed in the majority of human pituitary adenomas of gonadotrophic origin in parallel with Adrenal-4-binding protein/steroidogenic factor-1. [ABSTRACT FROM AUTHOR] |
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