Brain Tumors Research Today is a free monthly online journal that collates and summarizes the latest research about Brain Tumors, including details on symptoms, benign and malignant tumors, gliomas, screening, treatment.

Growth arrest of thyrotropic tumors by thyroid hormone is correlated with novel changes in Wnt-10A.

Kerr JM, Gordon DF, Woodmansee WW, Sarapura VD, Ridgway EC, Wood WM

University of Colorado Health Sciences Center, Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, MS8106, P.O. Box 6511 Denver, CO 80262, USA. janice.kerr@uchsc.edu

The molecular mechanism underlying thyroid hormone inhibition of thyrotrope cell growth is poorly understood. A comprehensive screen for T3-regulated genes involved in thyrotrope cell regulation was performed by Affymetrix MGU74A Genechip microarray analyses, which compared total RNA from hypothyroid versus 24 h T3-treated TtT-97 tumors. Of the 13,000 genes screened, a number of novel, T3-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 T3 by 6 h 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 T3 resulted in the decreased expression of Wnt-10A, and that thyroid hormone may inhibit growth via cyclin A regulation.

Published 14 June 2005 in Mol Cell Endocrinol, 238(1): 57-67.
Full-text of this article is available online (may require subscription).

© 2004-2010 Brain Tumors Research Today. All Rights Reserved.