Endocrine Abstracts

The human pituitary tumor transforming gene is overexpressed in thyroid cancers; inducing genetic instability through its role as a securin and propagating growth through induction of growth factors. We have demonstrated reduced cellular proliferation following hPTTG overexpression in neuronal cells. We hypothesised targeted hPTTG overexpression in mouse thyroids will result in hyperplastic/neoplastic growth and that stimulation of thyroid cell growth through standard methods ...

The key mitotic regulator pituitary tumor transforming gene (PTTG) is expressed at low levels in fetal brain compared with adult, and modulates the proliferation of human embryonic neuronal N-Tera2 (NT2) cells. We examined the function and expression of PTTG’s interacting partner separase, along with Rad21, the functional component of cohesin, which is cleaved by separase following interaction with PTTG. In contrast to PTTG, the cleaved forms of separase and Rad21 were hi...

By exploiting the canonical function of the sodium iodide symporter (NIS), ablative radioiodide therapy is an effective treatment for thyroid cancer. However, a subset of patients are unable to accumulate sufficient radioiodide due to decreased expression and/or plasma membrane localisation of NIS. Radioiodide therapy has been proposed as a viable treatment for breast cancer, but is hampered by low levels of NIS membrane localisation. Currently, the regulation of NIS trafficki...

By exploiting the canonical function of the sodium iodide symporter (NIS), ablative radioiodide therapy is an effective treatment for thyroid cancer. However, a subset of patients are unable to accumulate sufficient radioiodide due to decreased expression and/or plasma membrane localisation of NIS. Radioiodide therapy has been proposed as a viable treatment for breast cancer, but is hampered by low levels of NIS membrane localisation. Currently, the regulation of NIS trafficki...

Thyroid tumor progression is dependent on cell motility, a highly complex process that involves the co-ordination of cell adhesion, actin dynamics and signal transduction. The proto-oncogene pituitary tumor-transforming gene (PTTG)-binding factor (PBF/PTTG1IP) is a transmembrane glycoprotein that is overexpressed in thyroid cancer and associated with a poorer prognosis. PBF significantly promotes thyroid cancer cell migration and invasion through phosphorylation at PBF-Y174 by...

Background: The sodium/iodide symporter (NIS) frequently shows diminished targeting to the plasma membrane (PM) in differentiated thyroid cancer, resulting in suboptimal radioiodine treatment and poor prognosis. However, the mechanisms which govern the endocytosis of NIS away from the PM – its sole site of transport activity – are ill-defined, and may be of direct therapeutic potential. We previously showed that the proto-oncogene PBF binds NIS and enhances its inter...

Introduction: Radioactive iodine (RAI) therapy is a critical component in the post-surgical management of thyroid cancer patients, as well as being a central therapeutic option in the treatment of hyperthyroidism. Previous work suggests that antithyroid drugs hinder the efficacy of RAI therapy in patients. However, the effects of other background medications on RAI treatment efficacy have not been evaluated. Therefore, we performed a systematic review and metanalysis investiga...

Introduction: New drug approaches are urgently required to improve radioiodide (RAI) uptake for efficient ablation of thyroid cancer cells in RAI-refractory disease. Employing high-throughput screening of FDA-approved compounds we recently identified drugs capable of robust induction of sodium iodide symporter (NIS) activity to promote RAI uptake1. In particular, a leading drug candidate – the well-established anti-alcoholism drug disulfiram (DSF) – had no...

New targeted drug strategies are urgently needed to improve radioiodine uptake and efficiently ablate thyroid cancer cells thereby minimising the risk of recurrent disease. High-throughput screening (HTS) offers a promising approach to identify new candidate drugs that will induce sodium iodide symporter (NIS) function to promote iodide uptake. However, significant progress has been limited by a lack of thyroid cell-based assays amenable to HTS. Here, we constructed a thyroid ...

Successful responses to radioiodine treatment in differentiated thyroid cancer ultimately depend on uptake via the sodium-iodide symporter (NIS). However, many tumors exhibit NIS dysregulation, resulting in a poorer prognosis. Since breast cancer can also overexpress NIS, albeit of limited function, radioiodine treatment may be a promising treatment option. Our previous data show that overexpression of the pituitary tumor-transforming gene-binding factor (PBF) is partially res...