In situ hybridization analysis of neuronatin mRNA in the human pituitary gland and pituitary tumors
Ono, H.; Morii, K.; Tamura, T.; Tanaka, R.
Acta Medica et Biologica 51(1): 25-30
Object: We have recently cloned cDNA of human neuronatin. Northern blot and RT-PCR analyses revealed that mRNA are expressed in the fetal brain, adult anterior pituitary gland, and pituitary adenomas, but they are hardly detected in the adult brain and brain tumors. To clarify the role of this gene, we investigated the cellular localization of neuronatin mRNA using in situ hybridization (ISH). Methods: ISH and immunohistochemistry (IHC) were performed on serial frozen sections of three normal pituitary glands and tumors (10 GH-omas, 5 PRL-omas, 2 ACTH-omas, 10 nonfunctioning adenomas, 3 craniopharyngiomas, and 1 Rathke's cleft cyst). In ISH, a radiolabelled oligonucleotide probe for neuronatin was used. In IHC, antibodies to GH, PRL, FSH-beta, LH-beta, TSH-beta, and ACTH were used. Results: 1) Neuronatin mRNA was detected in the anterior pituitary gland, but not in the posterior gland; 2) Neuronatin expression was also observed in various pituitary adenomas and epithelial cells of Rathke's cleft cyst, but hardly detected in craniopharyngiomas; 3) In pituitary adenomas, neuronatin expression was seen irrespective of hormone productivity of each cell; Discussion: 1) Neuronatin is thought to participate in the development, differentiation, or maintenance of the pituitary gland and pituitary adenomas, though it is not involved in hormone productivity; 2) Information about the distribution of neuronatin may facilitate an understanding of the origin of pituitary tumors, including craniopharyngiomas and Rathke's cleft cysts.