Expression of D-type cyclins in normal and neoplastic rat pituitary

Endocrinology
X QianR V Lloyd

Abstract

The D-type cyclins (D1, D2, and D3) are involved in progression through the G1 phase of the cell cycle and are induced as part of the delayed early response to growth factor stimulation. To better understand the role of D-type cyclins in pituitary cell function and the regulatory role of growth factors in the cell cycle, we analyzed the expression and regulation of D-type cyclins in normal and neoplastic rat pituitary cells. Immunocytochemical and RT-PCR analyses showed expression of all three D-type cyclins in the normal pituitary, with higher percentages of positive cells by immunocytochemistry in the nuclei of normal pituitaries (D1, 20-30%; D2, 50-60%; D3, 70-80%), compared with GH3 cells. In the normal pituitary, there were significantly higher levels of cyclins D2 and D3 in PRL, GH, LH, and TSH cells, compared with ACTH cells. Cyclin D1 protein was not detected in GH3 cells, while D2 was present in less than 1 percent and D3 in 10-15 percent of GH3 cells. There were low levels of cyclin D1 and D2 messenger RNA expression in GH3 cells, by RT-PCR. When dissociated rat pituitary cells were cultured in the presence of basic fibroblast growth factor (5.6 nM) for 3 days, cyclin D2 was up-regulated 2-fold in normal PRL cells (co...Continue Reading

Citations

Jan 13, 2004·Proceedings of the National Academy of Sciences of the United States of America·Benson T AkingbemiMatthew P Hardy
Jan 24, 2012·Orthodontics & Craniofacial Research·E SuzukiA Yamane
Feb 13, 2002·Journal of Neurosurgery·Thomas A GaffeyAllan J Belzberg
Oct 23, 2003·Endocrine Reviews·Helen E TurnerJohn A H Wass

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