scholarly journals Expression and function of the novel proto-oncogene PBF in thyroid cancer: a new target for augmenting radioiodine uptake

2011 ◽  
Vol 210 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Vicki E Smith ◽  
Jayne A Franklyn ◽  
Christopher J McCabe

Pituitary tumor-transforming gene (PTTG)-binding factor (PBF; PTTG1IP) was initially identified through its interaction with the human securin, PTTG. Like PTTG, PBF is upregulated in multiple endocrine tumours including thyroid cancer. PBF is believed to induce the translocation of PTTG into the cell nucleus where it can drive tumourigenesis via a number of different mechanisms. However, an independent transforming ability has been demonstrated both in vitro and in vivo, suggesting that PBF is itself a proto-oncogene. Studied in only a limited number of publications to date, PBF is emerging as a protein with a growing repertoire of roles. Recent data suggest that PBF possesses a complex multifunctionality in an increasing number of tumour settings. For example, PBF is upregulated by oestrogen and mediates oestrogen-stimulated cell invasion in breast cancer cells. In addition to a possible role in the induction of thyroid tumourigenesis, PBF overexpression in thyroid cancers inhibits iodide uptake. PBF has been shown to repress sodium iodide symporter (NIS) activity by transcriptional regulation of NIS expression through the human NIS upstream enhancer and further inhibits iodide uptake via a post-translational mechanism of NIS governing subcellular localisation. This review discusses the current data describing PBF expression and function in thyroid cancer and highlights PBF as a novel target for improving radioiodine uptake and thus prognosis in thyroid cancer.

Thyroid ◽  
2000 ◽  
Vol 10 (11) ◽  
pp. 939-943 ◽  
Author(s):  
Jan W.A. Smit ◽  
Janny P. Schröder-van der Elst ◽  
Marcel Karperien ◽  
Ivo Que ◽  
Gabri van der Pluijm ◽  
...  

2004 ◽  
Vol 89 (12) ◽  
pp. 6168-6172 ◽  
Author(s):  
Anjli Venkateswaran ◽  
Derek K. Marsee ◽  
Steven H. Green ◽  
Sissy M. Jhiang

Abstract RET/PTC1, a thyroid-specific oncogene, has been reported to down-regulate sodium/iodide symporter (NIS) expression and function in vitro and in vivo. Recently, RET/PTC1 has been shown to interfere with TSH signaling at multiple levels in thyroid cells. The objective of this study was to investigate whether RET/PTC1-mediated NIS reduction can be rescued by activating cAMP-protein kinase A (PKA) pathways. We showed that both forskolin and 8-Br-cAMP increase radioiodide uptake and NIS protein in RET/PTC1-expressing cells to the same extent as the parental PC Cl 3 cells. We found that RET/PTC1 decreases nuclear localization of catalytic PKA, and forskolin treatment was able to counteract this RET/PTC1 effect. Furthermore, transient expression of catalytic PKA in the nucleus increased radioiodide uptake and NIS protein in RET/PTC1-expressing cells. Taken together, these studies suggest that RET/PTC1 down-regulates NIS expression by interrupting TSH/cAMP signaling, and this RET/PTC1 effect can be reversed by activating cAMP-PKA pathways.


2020 ◽  
Vol 11 ◽  
Author(s):  
Bihui Luo ◽  
Zhiyu He ◽  
Shijun Huang ◽  
Jinping Wang ◽  
Dunzheng Han ◽  
...  

Rationale: Cardiac fibrosis is observed in nearly every form of myocardial disease. Long non-coding RNAs (lncRNAs) have been shown to play an important role in cardiac fibrosis, but the detailed molecular mechanism remains unknown.Object: We aimed at characterizing lncRNA 554 expression in murine cardiac fibroblasts (CFs) after myocardial infarction (MI) to identify CF-enriched lncRNA and investigate its function and contribution to cardiac fibrosis and function.Methods and Results: In this study, we identified lncRNA NONMMUT022554 (lncRNA 554) as a regulator of MI-induced cardiac fibrosis. We found that lncRNA 554 was significantly up-regulated in the mouse hearts following MI. Further study showed that lncRNA 554 was predominantly expressed in cardiac fibroblasts, indicating a potential role of lncRNA 554 in cardiac fibrosis. In vitro knockdown of lncRNA 554 by siRNA suppressed fibroblasts migration and expression of extracellular matrix (ECM); while overexpression of lncRNA 554 promoted expression of ECM genes. Consistently, lentivirus mediated in vivo knockdown of lncRNA 554 could inhibit cardiac fibrosis and improve cardiac function in mouse model of MI. More importantly, TGF-β1 inhibitor (TEW-7197) could reverse the pro-fibrotic function of lncRNA 554 in CFs. This suggests that the effects of lncRNA 554 on cardiac fibrosis is TGF-β1 dependent.Conclusion: Collectively, our study illustrated the role of lncRNA 554 in cardiac fibrosis, suggested that lncRNA 554 might be a novel target for cardiac fibrosis.


Endocrinology ◽  
2012 ◽  
Vol 153 (7) ◽  
pp. 3526-3536 ◽  
Author(s):  
V. E. Smith ◽  
M. L. Read ◽  
A. S. Turnell ◽  
N. Sharma ◽  
G. D. Lewy ◽  
...  

Within the basolateral membrane of thyroid follicular epithelial cells, two transporter proteins are central to thyroid hormone (TH) biosynthesis and secretion. The sodium iodide symporter (NIS) delivers iodide from the bloodstream into the thyroid, and after TH biosynthesis, monocarboxylate transporter 8 (MCT8) mediates TH secretion from the thyroid gland. Pituitary tumor-transforming gene-binding factor (PBF; PTTG1IP) is a protooncogene that is up-regulated in thyroid cancer and that binds NIS and modulates its subcellular localization and function. We now show that PBF binds MCT8 in vitro, eliciting a marked shift in MCT8 subcellular localization and resulting in a significant reduction in the amount of MCT8 at the plasma membrane as determined by cell surface biotinylation assays. Colocalization and interaction between PBF and Mct8 was also observed in vivo in a mouse model of thyroid-specific PBF overexpression driven by a bovine thyroglobulin (Tg) promoter (PBF-Tg). Thyroidal Mct8 mRNA and protein expression levels were similar to wild-type mice. Critically, however, PBF-Tg mice demonstrated significantly enhanced thyroidal TH accumulation and reduced TH secretion upon TSH stimulation. Importantly, Mct8-knockout mice share this phenotype. These data show that PBF binds and alters the subcellular localization of MCT8 in vitro, with PBF overexpression leading to an accumulation of TH within the thyroid in vivo. Overall, these studies identify PBF as the first protein to interact with the critical TH transporter MCT8 and modulate its function in vivo. Furthermore, alongside NIS repression, PBF may thus represent a new regulator of TH biosynthesis and secretion.


2019 ◽  
Vol 26 (6) ◽  
pp. 963-972 ◽  
Author(s):  
Silvia Martina Ferrari ◽  
Marco Centanni ◽  
Camilla Virili ◽  
Mario Miccoli ◽  
Paola Ferrari ◽  
...  

Background: Sunitinib (SU11248) is an oral multi-target tyrosine kinase inhibitor (TKI) with low molecular weight, that inhibits platelet-derived growth factor receptors (PDGF-Rs) and vascular endothelial growth factor receptors (VEGFRs), c-KIT, fms-related tyrosine kinase 3 (FLT3) and RET. The concurrent inhibition of these pathways reduces tumor vascularization and causes cancer cell apoptosis, inducing a tumor shrinkage. Sunitinib is approved for the treatment of imatinib-resistant gastrointestinal stromal tumor (GIST), renal carcinoma, and pancreatic neuroendocrine tumors. Methods: We searched the literature on PubMed library. Results: In vitro studies showed that sunitinib targeted the cytosolic MEK/ERK and SAPK/JNK pathways in the RET/PTC1 cell inhibiting cell proliferation and causing stimulation of sodium/iodide symporter (NIS) gene expression in RET/PTC1 cells. Furthermore sunitinib is active in vitro and in vivo against anaplastic thyroid cancer (ATC) cells. Most of the clinical studies report that sunitinib is effective as first- and second-line TKI therapy in patients with advanced dedifferentiated thyroid cancer (DeTC), or medullary thyroid cancer (MTC). Sunitinib 37.5 mg/day is well tolerated, and effective. The most common adverse events include: reduction in blood cell counts (in particular leukocytes), hand-foot skin reaction, diarrhea, fatigue, nausea, hypertension, and musculoskeletal pain. Conclusion: Even if sunitinib is promising in the therapy of differentiated thyroid carcinoma (DTC), until now no phase III studies have been published, and additional prospective researches are necessary in order to evaluate the real efficacy of sunitinib in aggressive thyroid cancer.


2019 ◽  
Author(s):  
Alice Fletcher ◽  
Martin L. Read ◽  
Caitlin E.M. Thornton ◽  
Dean P. Larner ◽  
Vikki L. Poole ◽  
...  

ABSTRACTRadioiodine treatment fails ≥25% of patients with thyroid cancer and has been proposed as a potential treatment for breast cancer. Cellular iodide uptake is governed by the sodium iodide symporter (NIS), which is frequently mislocalized in thyroid and breast tumours. However, the trafficking of NIS to the plasma membrane (PM) is ill-defined. Through mass spectrometry, co-immunoprecipitation, cell surface biotinylation and proximity ligation assays we identify two proteins which control NIS subcellular trafficking: ADP-ribosylation factor 4 (ARF4) and valosin-containing protein (VCP). HiLo microscopy revealed ARF4 enhanced NIS trafficking in co-incident PM vesicles, governed by a C-terminal VXPX motif, whilst papillary thyroid cancers (PTC) demonstrate repressed ARF4 expression. In contrast, VCP, the central protein in ER-associated degradation, specifically bound NIS and decreased its PM localization. Five chemically distinct allosteric VCP inhibitors all overcame VCP-mediated repression of NIS function. In mice, two re-purposed FDA-approved VCP inhibitors significantly enhanced radioiodine uptake into thyrocytes, whilst human primary thyrocytes showed similar increases. Critically, PTC patients with high tumoural VCP expression who received radioiodine had strikingly worse disease-free survival. These studies now delineate the mechanisms of NIS trafficking, and for the first time open the therapeutic possibility of systemically enhancing radioiodine uptake in patients via FDA-approved drugs.One Sentence SummaryNovel NIS interactors ARF4 and VCP alter NIS trafficking in vitro, and FDA-approved VCP inhibitors can significantly enhance radioiodine uptake.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A1033-A1033
Author(s):  
Yang Han ◽  
Viktoria F Koehler ◽  
Nathalie Schwenk ◽  
Kathrin A Schmohl ◽  
Rebekka Spellerberg ◽  
...  

Abstract The sodium iodide symporter (NIS) mediates the active transport of iodide into thyroid follicular cells, providing the basis for the use of radioiodide for diagnostic imaging and therapy of differentiated thyroid cancer and also non-thyroidal tumors after tumor-selective NIS gene transfer. Based on their excellent tumor-homing capacity, mesenchymal stem cells (MSCs) can be employed as tumor-selective NIS gene delivery vehicles. Transgenic expression of NIS in genetically engineered MSCs allows noninvasive imaging of functional NIS expression as well as therapeutic application of 131I. The use of promoters activated by tumor micromilieu-derived signals to drive NIS expression enhances selectivity and effectiveness, while limiting potential off-target effects. In this study we aimed to exploit the central role of transforming growth factor B1 (TGFB1) in tumor milieu-associated signaling using a TGFB1-inducible synthetic SMAD-responsive promoter to selectively drive NIS-transgene expression in engineered MSCs (SMAD-NIS-MSC) in the context of differentiated thyroid cancer based on the critical role of TGFB1 in the pathogenesis of radioiodine refractory differentiated thyroid cancer. To evaluate the TGFB1 expression in thyroid cancer cell lines, the TGFB1 concentration in conditioned medium (CM) from an array of established human papillary thyroid cancer (PTC) cell lines (BCPAP and K1) was measured by ELISA. BCPAP-CM showed a higher concentration of TGFB1, while a lower concentration was measured in K1-CM. Stimulation of SMAD-NIS-MSCs with PTC-CM showed a significant increase of NIS-mediated radioiodide-125 uptake in these MSCs in vitro. In addition, iodide uptake in SMAD-NIS-MSCs was significantly stimulated by co-culture with thyroid cancer cells. Cell migration assay was performed to validate the effect of PTC-CM in MSC recruitment. MSCs subjected to a gradient between tumor CM and serum free medium showed a directed chemotaxis towards CM with increased forward migration index (FMI) and center of mass (CoM). In a next step, based on the in vitro studies, SMAD-NIS-MSCs will be systemically applied via the tail vein to mice harboring subcutaneous PTC tumors and tumoral iodide uptake will be monitored by 123I-scintigraphy. Taken together, these data indicate the feasibility of commandeering TGF-β/SMAD signaling in the TGFB1-rich tumor environments of radioiodine refractory differentiated thyroid carcinomas to re-establish functional NIS expression using engineered mesenchymal stem cells as therapy vehicles.


2006 ◽  
Vol 13 (3) ◽  
pp. 797-826 ◽  
Author(s):  
T Kogai ◽  
K Taki ◽  
G A Brent

The sodium/iodide symporter (NIS) mediates iodide uptake in the thyroid gland and lactating breast. NIS mRNA and protein expression are detected in most thyroid cancer specimens, although functional iodide uptake is usually reduced resulting in the characteristic finding of a ‘cold’ or non-functioning lesion on a radioiodine image. Iodide uptake after thyroid stimulating hormone (TSH) stimulation, however, is sufficient in most differentiated thyroid cancer to utilize β-emitting radioactive iodide for the treatment of residual and metastatic disease. Elevated serum TSH, achieved by thyroid hormone withdrawal in athyreotic patients or after recombinant human thyrotropin administration, directly stimulates NIS gene expression and/or NIS trafficking to the plasma membrane, increasing radioiodide uptake. Approximately 10–20% differentiated thyroid cancers, however, do not express the NIS gene despite TSH stimulation. These tumors are generally associated with a poor prognosis. Reduced NIS gene expression in thyroid cancer is likely due in part, to impaired trans-activation at the proximal promoter and/or the upstream enhancer. Basal NIS gene expression is detected in about 80% breast cancer specimens, but the fraction with functional iodide transport is relatively low. Lactogenic hormones and various nuclear hormone receptor ligands increase iodide uptake in breast cancer cells in vitro, but TSH has no effect. A wide range of ‘differentiation’ agents have been utilized to stimulate NIS expression in thyroid and breast cancer using in vitro and in vivo models, and a few have been used in clinical studies. Retinoic acid has been used to stimulate NIS expression in both thyroid and breast cancer. There are similarities and differences in NIS gene regulation and expression in thyroid and breast cancer. The various agents used to enhance NIS expression in thyroid and breast cancer will be reviewed with a focus on the mechanism of action. Agents that promote tumor differentiation, or directly stimulate NIS gene expression, may result in iodine concentration in ‘scan-negative’ thyroid cancer and some breast cancer.


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