부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.mce.2005.03.004 Byline: Janice M. Kerr, David F. Gordon, Whitney W. Woodmansee, Virginia D. Sarapura, E. Chester Ridgway, William M. Wood Abstract: The molecular mechanism underlying thyroid hormone inhibition of thyrotrope cell growth is poorly understood. A comprehensive screen for T.sub.3-regulated genes involved in thyrotrope cell regulation was performed by Affymetrix MGU74A Genechip microarray analyses, which compared total RNA from hypothyroid versus 24h T.sub.3-treated TtT-97 tumors. Of the 13,000 genes screened, a number of novel, T.sub.3-responsive candidate genes were identified. Within the Wnt family of growth factors, only Wnt-10A transcripts were abundantly expressed in hypothyroid TtT-97 tumors, and were down-regulated with T.sub.3 by 6h of treatment. In addition, nuclear [beta]-catenin, which is a downstream mediator of canonical Wnt signaling, was decreased at the protein and functional levels. TtT-97 growth suppression was associated with decreased cyclin A transcript levels. We conclude that treatment of thyrotropic TtT-97 tumors with T.sub.3 resulted in the decreased expression of Wnt-10A, and that thyroid hormone may inhibit growth via cyclin A regulation. Author Affiliation: University of Colorado Health Sciences Center, Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, MS8106, P.O. Box 6511 Denver, CO 80262, USA