Endocrine Abstracts

Vascular endothelial growth factors (VEGFs) support angiogenesis and thus tissue growth. They are synthesised and secreted by several cell types but their actions are normally limited to endothelial cells which express VEGF receptors (VEGFRs). Using qRT-PCR and Western blotting we found that normal human thyroid follicular cells also express VEGFRs (VEGFR1-3, neuropilin1 and 2). We have examined the regulation of the expression of VEGFs and PlGFs in the cells. Cells were fully...

We have recently shown that human thyroid follicular cells in culture secrete large amounts of active plasminogen activators (PAs). Thyroid cells also secrete large amounts of vascular endothelial growth factors (VEGFs) and express their receptors, the VEGFRs. PAs, as serine proteases, are known to process growth factors, particularly VEGFs into active forms. In endothelial cells, VEGFs stimulate PA production. We examined the effect of inhibiting VEGF signalling on thyroid fo...

Using qRT-PCR, we found that normal human thyroid follicular cells in culture express the mRNAs for the receptors for vascular endothelial growth factors (VEGFRs). qRT-PCR revealed that the relative production of mRNAs for VEGFRs was neuropilin1=neuropilin2=VEGFR2>VEGFR1 >VEGFR3. Western blotting for phosphoVEGFR2 showed labelling of a 235 kDa protein with few degradation products. VEGFR2 is likely in its active, phosphorylated form, because thyroid cells secrete large...

Human thyroid follicular cells in culture synthesise plasminogen activators, both urokinase (uPA) and tissue-type (tPA). The PAs secreted into the culture medium were active (2.5–50 U/ml) and able to mediate the conversion of plasminogen to plasmin. Secreted PA activity (PAA) was markedly increased by epidermal growth factor (EGF) and protein kinase C (PKC) activation with TPA. There was a corresponding increase in uPA and tPA mRNA levels and in uPA and tPA protein secret...

The human pituitary tumor transforming gene (hPTTG) is overexpressed in thyroid cancers; it induces genetic instability and propagates growth through the induction of growth factors. We investigated the pathways of interaction between hPTTG and epidermal growth factor (EGF), transforming growth factor-α (TGF-α), insulin-like growth factor 1 (IGF1) and basic fibroblast growth factor (FGF2) in vitro and in vivo. Synchronised K1 and TPC-1 papillary thyroid...

Iodide uptake via the sodium iodide symporter (NIS) is reduced in many thyroid cancers, resulting in poor prognosis following treatment with 131I. The pituitary tumor transforming gene (PTTG) and its binding factor (PBF) are proto-oncogenes implicated in thyroid tumourigenesis and we previously demonstrated PTTG and PBF-induced repression of NIS in vitro. We have recently generated murine transgenic models of targeted overexpression of PBF and PTTG in the thy...

The human pituitary tumor transforming gene (hPTTG) is overexpressed in thyroid cancers; it induces genetic instability and propagates growth through the induction of growth factors. We set out to investigate the autocrine and paracrine pathways of interaction between hPTTG and epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and insulin-like growth factor 1 (IGF1) in vitro and in vivo. Synchronised K1 papillary thyroid carcinoma cell...

Inadequate dietary iodine intake is the most common cause of preventable mental impairment worldwide and is defined by the WHO as a population median urinary iodine (UI) excretion <100 μg/l. No contemporary data are available for the UK according to the ICCIDD. The UK has no programme of food/salt iodination.We have performed a systematic assessment of the current UK iodine status in 14–15 years old schoolgirls. Seven hundred and eighty-fiv...