Endocrine Abstracts

PTTG transforms cells in vitro, is tumourigenic in vivo and regulates secretion of fibroblast growth factor-2 (FGF-2). Critical to transactivation of FGF-2 is PTTG's SH3 interacting domain which encodes the gene's sole phosphorylation site. We explored the mechanisms through which PTTG stimulates FGF-2 expression and cell transformation using specific mutations resulting in unphosphorylated PTTG (phos-), a mimic of constitutive phosphorylation (phos+), and a disr...

Pituitary tumourigenesis is a complex and poorly understood process. Crucial to the initiation and growth of such tumours is the oncogene PTTG, which stimulates FGF-2-mediated angiogenesis. We recently investigated expression of the angiogenic factor VEGF and its receptor KDR in 103 pituitary tumours. Non-functioning tumours demonstrated markedly raised VEGF mRNA (3.2-fold, P<0.05) and protein levels compared to normal pituitaries (N=10). KDR was also highly induced in NFTs...

PTTG has a dual role in tumorigenesis. Firstly, it regulates expression of basic fibroblast growth factor (FGF-2), and secondly, as a human securin homologue, it inhibits sister chromatid separation in mitosis. Securins must be degraded at Destruction Box (DB) motifs by an anaphase promoting complex (APC), before cell division can proceed. We have used a variety of approaches to examine the precise roles of the PTTG Destruction Box and FGF-2 stimulation in cell transformation....