Abstract
Stem cells have the ability to self-renew and to differentiate into hormone-producing cells, and have been reported to possibly be involved in the formation of pituitary adenomas. In the present study, we analyzed the properties of stem cells in pituitary adenomas by analyzing the expression of stem cell-specific markers in pituitary adenomas. Frozen sections were prepared from surgically resected pituitary adenomas, and adenoma cells were then isolated using laser microdissection. Following total RNA extraction, cDNA was synthesized using the RT2 Profiler PCR Array System and PCR was performed using the ABI PRISM®7000 Sequence System. Specific markers were detected with the PAHS-405A array plate and analyzed using the ΔCT method following correction in reference to RNA data for normal pituitary tissue. Cyclin D1, which is involved in the cell cycle, was detected in all pituitary adenomas. The NEUROG2 gene, which is involved in neurogenesis, was more highly expressed in functional pituitary adenomas than in non-functioning pituitary adenomas. SOX2, a transcription factor and cofactor specific to the pituitary gland, was detected in functional pituitary adenomas but not non-functioning pituitary adenomas. ISL1, a gene involved in differentiation from embryonic cells, was detected in non-functioning pituitary adenomas but not in functional pituitary adenomas. More undifferentiated cells were present in non-functioning pituitary adenomas compared to functional pituitary adenomas, suggesting that more stem cells are present in the former, which does not involve hormone secretion.
