Sensitive, non-immunogenic in vivo imaging of cancer metastases and immunotherapy response.

Non-invasive imaging of tumors expressing reporter transgenes is a popular preclinical method for studying tumor development and response to therapy in vivo due to its ability to distinguish signal from tumors over background noise. However, the utilized transgenes, such as firefly luciferase, are immunogenic and, therefore, impact results when expressed in immune-competent hosts. This represents an important limitation, given that cancer immunology and immunotherapy are currently among the most impactful areas of research and therapeutic development. Here we present a non-immunogenic preclinical tumor imaging approach. Based on the expression of murine sodium iodide symporter (mNIS), it facilitates sensitive, non-invasive detection of syngeneic tumor cells in immune-competent tumor models without additional immunogenicity arising from exogenous transgenic protein or selection marker expression. NIS-expressing tumor cells internalize the gamma-emitting [99mTc]pertechnetate ion and so can be detected by SPECT (single photon emission computed tomography). Using a mouse model of pancreatic ductal adenocarcinoma hepatic metastases in immune-competent C57BL/6 mice, we demonstrate that the technique enables the detection of very early metastatic lesions and longitudinal assessment of immunotherapy responses using precise and quantifiable whole-body SPECT/CT imaging.

False-positive radioiodine uptake after radioiodine treatment in differentiated thyroid cancer.

BACKGROUND AND PURPOSE: False-positive radioiodine uptake can sometimes be observed with post-radioiodine treatment (RIT) whole body scanning. Radioiodine pitfall has often been reported as being caused by benign or inflammatory disease, or, in some cases, by tumor lesions. This paper reviews the possible causes of such false-positive imaging, and suggests possible reasons for suspecting these pitfalls. METHODS AND RESULTS: Online databases, including MEDLINE (via PubMed), Embase, ISI Web of Science, Google Scholar, and Scopus, were systematically examined, using different keyword combinations: "radioiodine false-positive imaging", "131 I false-positive imaging" and " RAI false-positive imaging". An illustrative case was described. Excluding cases in which SPECT/CT was not performed, a total of 18 papers was found: 17 case reports and one series regarding false-positive iodine-131 uptake after RIT. CONCLUSIONS: The prevalence of radioiodine pitfall was significantly reduced through the use of SPECT/CT imaging, though its possible presence has always to be taken into account. Inflammation, passive iodine accumulation, other tumors, and, sometimes, unknown causes can all potentially generate false-positive imaging. Missing detection of false-positive imaging could result in over-staging and inappropriate RIT or it could lead to the non-detection of other cancers. We examine the reasons for these possible pitfalls.

Proteomic analysis of radioiodine-refractory differentiated thyroid cancer identifies CHI3L1 upregulation in association with dysfunction of the sodium-iodine symporter.

Radioiodine refractory differentiated thyroid cancer (RR-DTC) is the main factor adversely affecting the overall survival rate of patients with thyroid cancer. The aim of the present study was to investigate the underlying molecular mechanism of pathogenesis of RR-DTC and to explore novel therapeutic targets for clinical treatment. A proteomic analysis was performed using the tumor tissues of patients with RR-DTC. A total of 6 metastatic lymph nodes were collected during lymph node dissection, 3 from patients with RR-DTC and 3 from patients with papillary thyroid cancer. The expression of chitinase-3-like 1 (CHI3L1) and sodium-iodine symporter (NIS) in the tumor tissue was detected by immunohistochemistry (IHC). Western blotting was used to detect the expression of CHI3L1, phosphorylated (p)-MEK and p-ERK1/2 in PTC-K1 cells transfected with CHI3L1 overexpression vector. The proteomic analysis identified 665 differentially expressed proteins (DEPs), including 327 upregulated and 338 downregulated proteins in the RR-DTC group, which were enriched in 59 signaling pathways by Kyoto Encyclopedia of Genes and Genomes database analysis. In particular, CHI3L1 was demonstrated to be significantly upregulated in RR-DTC as evidenced by quantitative proteomic analysis and IHC. Western blotting suggested that the overexpression of CHI3L1 activated the MEK/ERK1/2 signaling pathway, which may lead to NIS dysfunction. In conclusion, the present study suggests that CHI3L1 is a potential molecular target for the radiotherapy of patients with RR-DTC.

Inhibition of ALK-Signaling Overcomes STRN-ALK-Induced Downregulation of the Sodium Iodine Symporter and Restores Radioiodine Uptake in Thyroid Cells.

Background: Radioiodine (RAI) is commonly used for thyroid cancer treatment, although its therapeutic benefits are restricted to iodine-avid tumors. The RAI-refractory disease develops with tumor dedifferentiation involving loss of sodium-iodine symporter (NIS). Thyroid cancers driven by ALK fusions are prone to dedifferentiation, and whether targeted ALK inhibition may enhance RAI uptake in these tumors remains unknown. The aim of this study was to determine the levels of NIS expression during the progression of ALK fusion-driven thyroid cancer, assess the effects of ALK activation on NIS-mediated RAI uptake, and test pharmacological options for its modulation. Methods: The expression of NIS at different stages of ALK-driven carcinogenesis was analyzed using a mouse model of STRN-ALK-driven thyroid cancer. For in vitro experiments, a system of doxycycline-inducible expression of STRN-ALK was generated using PCCL3 normal thyroid cells. The STRN-ALK-induced effects were evaluated with quantitative reverse transcription polymerase chain reaction, Western blot, immunofluorescence, RNA sequencing, and gene sets pathways analyses. RAI uptake was measured using 131I. Treatment experiments were done with FDA-approved ALK inhibitors (crizotinib and ceritinib), MEK inhibitor selumetinib, and JAK1/2 inhibitor ruxolitinib. Results: We found that Nis downregulation occurred early in ALK-driven thyroid carcinogenesis, even at the stage of well-differentiated cancer, with a complete loss in poorly differentiated thyroid carcinomas. Acute STRN-ALK expression in thyroid cells resulted in increased MAPK, JAK/STAT3, and PI3K/AKT/mTOR signaling outputs associated with significant ALK-dependent downregulation of the majority of thyroid differentiation and iodine metabolism/transport genes, including Slc5a5 (Nis), Foxe1, Dio1, Duox1/2, Duoxa2, Glis3, Slc5a8, and Tg. Moreover, STRN-ALK expression in thyroid cells induced a significant loss of membranous NIS and a fourfold decrease of the NIS-mediated RAI uptake, which were reversed by ALK inhibitors crizotinib and ceritinib. In addition, a strong dose-dependent restoration of NIS with its membranous redistribution in STRN-ALK-expressing thyroid cells was observed after inhibition of MAPK signaling with selumetinib, which exhibited a cumulative effect with JAK1/2 inhibitor ruxolitinib. Conclusions: The findings of this preclinical study showed that ALK fusion-induced downregulation of NIS, the prerequisite of RAI refractoriness, could be reversed in thyroid cells by either direct inhibition of ALK or its downstream signaling pathways.

Hydrogen-Bonded Organic Framework for High-Performance Lithium/Sodium-Iodine Organic Batteries.

The rechargeable lithium/sodium-iodine battery (Li/Na-I2 ) is a promising candidate for meeting the growing energy demand. Herein, a flexible hydrogen-bonded organic framework (HOF) linked to the Ti3 C2 Tx MXene complex (HOF@Ti3 C2 Tx ) has been presented for iodine loading. HOF is self-assembled by organic monomers through hydrogen bonding interactions between each monomer. It leads to numerous cavities in HOF structure, which can encapsulate iodine through various adsorptive sites and intermolecular interactions. The unique structure of complex can accelerate the nucleation of iodine, achieve fast reaction kinetics, stabilize iodide and retard the shuttle effect, thus improving the cycling stability of I2 -based batteries. The I2 /HOF@Ti3 C2 Tx exhibits large reversible capacities of 260.2 and 207.6 mAh g-1 at 0.2 C after repeated cycling for Li-I2 and Na-I2 batteries, respectively. This work can gain insights into the HOF-related energy storage application with reversible iodine encapsulation and its related redox reaction mechanisms with Li and Na metal ions.

Capsaicin restores sodium iodine symporter-mediated radioiodine uptake through bypassing canonical TSH‒TSHR pathway in anaplastic thyroid carcinoma cells.

Anaplastic thyroid cancer (ATC) is a rare but highly lethal disease. ATCs are resistant to standard therapies and are extremely difficult to manage. The stepwise cell dedifferentiation results in the impairment of the iodine-metabolizing machinery and the infeasibility of radioiodine treatment in ATC. Hence, reinducing iodine-metabolizing gene expression to restore radioiodine avidity is considered as a promising strategy to fight against ATC. In the present study, capsaicin (CAP), a natural potent transient receptor potential vanilloid type 1 (TRPV1) agonist, was discovered to reinduce ATC cell differentiation and to increase the expression of thyroid transcription factors (TTFs including TTF-1, TTF-2, and PAX8) and iodine-metabolizing proteins, including thyroid-stimulating hormone receptor (TSHR), thyroid peroxidase, and sodium iodine symporter (NIS), in two ATC cell lines, 8505C and FRO. Strikingly, CAP treatment promoted NIS glycosylation and its membrane trafficking, resulting in a significant enhancement of radioiodine uptake of ATC cells in vitro. Mechanistically, CAP-activated TRPV1 channel and subsequently triggered Ca2+ influx, cyclic adenosine monophosphate (cAMP) generation, and cAMP-responsive element-binding protein (CREB) signal activation. Next, CREB recognized and bound to the promoter of SLC5A5 to facilitate its transcription. Moreover, the TRPV1 antagonist CPZ, the calcium chelator BAPTA, and the PKA inhibitor H-89 effectively alleviated the redifferentiation exerted by CAP, demonstrating that CAP might improve radioiodine avidity through the activation of the TRPV1‒Ca2+/cAMP/PKA/CREB signaling pathway. In addition, our study indicated that CAP might trigger a novel cascade to redifferentiate ATC cells and provide unprecedented opportunities for radioiodine therapy in ATC, bypassing canonical TSH‒TSHR pathway.

El tratamiento paciente específico del hipertiroidismo con radioyodo: una oportunidad a la mejora / Radioiodine treatment of hyperthyroidism with patient-specific techniques: an improvement opportunity

Introducción: La aplicación de actividades fijas en el tratamiento del hipertiroidismo con I131 (yoduro de sodio, conocido también como radioyodo), es el método más usado en nuestro país, a pesar de la individualidad morfo-funcional que caracteriza esta afección. Sin embargo, no existe aún, un consenso internacional sobre la dosis más conveniente para cada caso, y por ende, los resultados no siempre son los deseados. Objetivo: Evaluar la aplicabilidad de varios métodos de cálculo de dosis paciente-específica para el tratamiento de hipertiroidismo con yoduro de sodio. Métodos: Se realizó un análisis de los resultados de varios métodos de cálculo de dosis recomendados internacionalmente a partir de la actividad fija prescrita en 10 pacientes, con el empleo de tecnologías y herramientas ya desarrolladas y disponibles en el país. Se evaluó la variabilidad inter-especialista y su impacto en la dosis planificada para el tratamiento. Resultados: El uso de la información incompleta de la biodistribución y farmacocinética del paciente produjo diferencias entre -42 por ciento y 37 por ciento de las dosis para el mismo paciente. El resultado de la comparación del método de cálculo recomendado por la Sociedad Europea de Medicina Nuclear, manejando la masa por gammagrafía-2D / 3D y por ultrasonido, arrojó diferencias no significativas entre sí. La variabilidad inter-especialista de las actividades prescrita mostró diferencias significativas, que arrojan sobre el mismo paciente, discrepancias entre 44Gy y 243Gy de las dosis terapéuticas a recibir, situación que puede comprometer el éxito del tratamiento y producir efectos secundarios no deseados. Conclusiones: Las técnicas dosimétricas paciente-específicas se pueden implementar satisfactoriamente en nuestro país. Las diferencias numéricas encontradas, especialmente la variabilidad inter-especialista, demuestran la no estandarización terapéutica, lo que apoya el uso de la farmacocinética paciente-específica pre terapéutica y la masa por gammagrafía-3D para planificar el tratamiento siempre que sean posible(AU)

Introduction: Despite of its typical morpho-functional individuality, fixed activities remain as the most used method in Cuba for hyperthyroidism treatment with I (sodium iodide, also known as radioiodine). However, there is not yet an international consensus on the most convenient doses for each case, so, the results are not always the desired ones. Objective: To evaluate the applicability of various patient-specific dose calculation methods for the treatment of hyperthyroidism with sodium iodide. Methods: It was carried out an analysis in 10 patients of the results of some methods for dose calculation from the prescribed fixed activity recommended internationally, with the use of technologies and tools already developed and available in the country. The inter-specialist variability and its impact in the planned dose for the treatment were assessed. Results: The use of uncompleted biodistribution and pharmacokinetics information of the patient showed differences between -42 percent and 37 percent in the doses for the same patient. The outcome of the comparison of the calculation method recommended by the European Society of Nuclear Medicine managing the mass by 3D/2D gammagraphy and ultrasound, presented no significant discrepancies among them. The inter-specialist variability of prescribed activity was statistically significant, and it can produce in the same patient differences between 44Gy and 243Gy of the therapeutic doses, which could affect the treatment success and lead to unnecessary side effects. Conclusions: The patient´s personalized calculation methods can be satisfactorily applied in Cuba. The numeric differences found, especially inter-specialist variability, show the lack of therapeutic standardization, which supports the use of pre-therapeutic patient-specific pharmacokinetics and the mass by 3D-gammagraphy to plan the treatment when possible(AU)

Theranostics in Thyroid Cancer.

The main targeting structure for theranostics in thyroid cancer is the sodium-iodine symporter (NIS), which has been used in clinical routine for the diagnosis and treatment of thyroid diseases for more than 70 years. Because the different iodine (I) nuclides (123I, 124I, 131I) have the same kinetics, uniquely congruent theranostics are possible in differentiated thyroid cancer. Besides the NIS, there are further possibilities by using expression of somatostatin receptors or the expression of the prostate-specific membrane antigen, for example, in radioiodine-refractory differentiated thyroid cancer, medullary thyroid cancer, or anaplastic thyroid cancer.

Quantification of Boron Compound Concentration for BNCT Using Positron Emission Tomography.

Background: Boron neutron capture therapy requires a 2 mM 10B concentration in the tumor. The well-known BNCT patient treatment method using boronophenylalanine (BPA) as a boron-carrying agent utilizes [18F]fluoroBPA ([18F]FBPA) as an agent to qualify for treatment. Precisely, [18F]FBPA must have at least a 3:1 tumor to background tissue ratio to qualify the patient for BNCT treatment. Normal, hyperplasia, and cancer thyroids capture iodine and several other large ions, including BF4-, through a sodium-iodine symporter (NIS) expressed on the cell surface in normal conditions. In cancer, NIS is also expressed within the thyroid cell and is not functional. Methods: To visualize the thyroids and NIS, we have used a [18F]NaBF4 positron emission tomography (PET) tracer. It was injected into the tail veins of rats. The [18F]NaBF4 PET tracer was produced from NaBF4 by the isotopic exchange of natural 19F with radioactive 18F. Rats were subject to hyperplasia and tumor-inducing treatment. The NIS in thyroids was visualized by immunofluorescence staining. The boron concentration was calculated from Standard Uptake Values (SUV) in the PET/CT images and from the production data. Results: 41 MBq, 0.64 pmol of [18F]NaBF4 PET tracer that contained 0.351 mM, 53 nmol of NaBF4 was injected into the tail vein. After 17 min, the peak activity in the thyroid reached 2.3 MBq/mL (9 SUVmax). The natB concentration in the thyroid with hyperplasia reached 381 nM. Conclusions: Such an incorporation would require an additional 110 mg/kg dose of [10B]NaBF4 to reach the necessary 2 mM 10B concentration in the tumor. For future BNCT treatments of thyroid cancer, contrary to the 131I used now, there is no post-treatment radioactive decay, the patient can be immediately discharged from hospital, and there is no six-month moratorium for pregnancy. This method can be used for BNCT treatment compounds of the type R-BFn, where 1 <= n <= 3, labeled with 18F relatively easily, as in our example. A patient may undergo injection of a mixture of nonradioactive R-BFn to reach the necessary 10B concentration for BNCT treatment in the tumor together, with [18F]R-BFn for boron mapping.

Targeting uptake transporters for cancer imaging and treatment.

Cancer cells reprogram their gene expression to promote growth, survival, proliferation, and invasiveness. The unique expression of certain uptake transporters in cancers and their innate function to concentrate small molecular substrates in cells make them ideal targets for selective delivering imaging and therapeutic agents into cancer cells. In this review, we focus on several solute carrier (SLC) transporters known to be involved in transporting clinically used radiopharmaceutical agents into cancer cells, including the sodium/iodine symporter (NIS), norepinephrine transporter (NET), glucose transporter 1 (GLUT1), and monocarboxylate transporters (MCTs). The molecular and functional characteristics of these transporters are reviewed with special emphasis on their specific expressions in cancers and interaction with imaging or theranostic agents [e.g., I-123, I-131, 123I-iobenguane (mIBG), 18F-fluorodeoxyglucose (18F-FDG) and 13C pyruvate]. Current clinical applications and research areas of these transporters in cancer diagnosis and treatment are discussed. Finally, we offer our views on emerging opportunities and challenges in targeting transporters for cancer imaging and treatment. By analyzing the few clinically successful examples, we hope much interest can be garnered in cancer research towards uptake transporters and their potential applications in cancer diagnosis and treatment.

Correlation between urinary iodine and clinical characteristics in breast cancer / 中国医师杂志

Objective To explore the relationship between urinary iodine level and breast cancer,we compare urinary iodine excretion levels in patients with breast cancer,benign breast disease,other female malignant tumors and control subjects in Xiangya Hospital of Central South University.Methods From December 2018 to January 2019,64 patients with newly diagnosed breast cancer in Xiangya Hospital of Central South University were selected as case group,benign breast disease group (n =49),other female malignant tumor group (n =39) and health examination group (n =50) as control group.Urinary iodine was determined by colorimetry.According to the urinary iodine level the patients divided into three groups:iodine excess (＞300 μg/L),medium iodine (100-300 μg/L) and iodine deficiency (＜ 100 μg/L).The relationship between urinary iodine and clinicopathology of breast cancer was analyzed.Results The level of urinary iodine in benign breast nodule group 319.13 (163.98) μg/L ＞ breast cancer group 273.96 (151.30) μg/L ＞ female other malignant tumor group 212.95 (161.71) μg/L ＞ normal control group 199.15 (194.45) μg/L,with significantly differance (H =9.936,P =0.019).Urinary iodine level in the normal control group was significantly lower than that in the benign breast disease group (P =0.013).The patients were further divided into three groups according to the urinary iodine level:iodine excess,iodine medium and iodine deficiency,the number of urine iodine ＜ 100 μg/L in the normal control group was significantly higher than that in the breast cancer group (P =0.021).The level of urinary iodine was negatively correlated with the size of the primary focus of breast cancer (Z =-2.307,P =0.021).The effect of urinary iodine was analyzed by multiple linear regression method.The size of primary focus was included in the regression equation (R2 =0.136,P=0.007),but had nothing to do with lymph node metastasis and the expression status of estrogen receptor (ER),androgen receptor (AR),progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2).Conclusions There is a negative linear correlation between urinary iodine level and the size of primary focus of breast cancer,but it has nothing to do with lymph node metastasis and the expression of ER,AR,PR and HER-2.

[ß-catenin nuclear translocation represses thyroid cancer stem cells differentiating into cells with sodium-iodine symporter functional expression].

Objective: To confirm whether ß-catenin nuclear translocation in thyroid cancer stem cells can differentiate into thyroid cancer cells without functional membrane expression of sodium-iodine transporter (NIS) and be resistant to iodide 131 treatment. Methods: Thyroid cancer stem cells were firstly isolated as a side population (SP) from human thyroid cancer cell line FTC133. The SP cells from FTC133 were transfected with ß-catenin, and then differentiated. The cells were further collected for Western blot, Transwell and MTT assay to investigate the epithelial-mesenchymal transition (EMT) characteristics, tumor growth, invasion, and iodine uptake potency in vitro. Functional NIS expression and iodide uptake in differentiated cells were detected with immunofluorescent staining and iodide uptake assay, respectively. Subcutaneous severe combined immunodeficient (SCID) mice tumor model was induced with differentiated cancer cells to explore the in vivo effect of radioiodine treatment. Further immunohistochemical staining was performed to reveal the changes of functional proteins involved in tumor radioiodine treatment. Results: Side population was isolated from FTC133 accounting for about 0.03%, with high expression of stem cell markers and decreased expression of differentiated cell markers. Western blot showed prominent EMT phenotype in the differentiated cells from ß-catenin transfected stem cell model, with absence of epithelial expression of E-cadherin and cytokeratin 18, as well as abnormal expression of vimentin,fibronectin and urokinase-type plasminogen activator. Moreover,compared with cells differentiated from untransfected or empty plasmid transfected stem cells, in vitro proliferation markedly increased 85.4% and 81.0%, respectively (both P<0.01); while in vitro invasion augmented 78.8% and 84.4%, respectively (both P<0.01). Immunofluorescent staining identified that, after transfected with ß-catenin, differentiated cells underwent ß-catenin nuclear translocation and NIS localization transferred from membrane to plasma, compared with cells from untransfected or empty plasmid transfected stem cells. Cell iodide uptake in vitro decreased about 52.8% and 45.2%, respectively (both P<0.01). Furthermore, in vivo experiment further demonstrated that, cells differentiated from ß-catenin transfected stem cells were found with much higher tumor proliferation,tumor growth rate and larger tumor mass after radioiodine 131 treatment (both P<0.05). Conclusion: Induction of ß-catenin nuclear translocation in stem cells may generate differentiated thyroid cancer cells that are not sensitive to radioiodine treatment.

Impact of low iodine on thyroid structure and iodine uptake function in parental and second filial generation rats / 中华地方病学杂志

Objective To observe the effect of long-term intake of low iodine diet on thyroid morphological structure and sodium iodine transporter (NIS) in parental and second filial generation rats, and to explore the changes of NIS protein expression in iodine deficiency disease (IDD), so as to further verify and explore the mechanism of IDD. Methods Referring to "Nutritional Composition of Experimental Animals With Feed" (GB 14924.3-2010), the crops widely planted and with high edible rate in the traditional cretinism epidemic area of Xinjiang were used as the main feed components to prepare different levels of iodine (low iodine groups 1 and 2 feed the iodine contents were about 50 and 20 μg/kg). The IDD rat model was established by the three-generation two-nest method, that is, 132 SPF Wistar rats were selected after weaning, half males and half females, randomly divided into 3 groups according to body mass by random number table method: control group (N, 52 rats, 22 females, 30 males, the iodine content was about 300 μg/kg), low iodine groups 1 and 2 (LⅠ, LⅡ, 40 rats, 22 females, 18 males in each group). Twelve rats in each group were sacrificed at the end of 3, 6, 9 months, respectively, half males and half females. The relative weight of thyroid was calculated and the gross structure and microscopic pathology were observed. The expression of NIS protein was determined by Western blotting. At the end of 3 months after feeding, four female rats in each group were selected to mate with male rats in group N in 1 : 1, and the newborn mice were fed the same way for three months and then subcultured again. The rat generation continued to be fed according to the mother group, and 10-12 rats were sacrificed at the end of 3, 6, 9 months, respectively, and the specimens and observation indexes results were collected same as the parental rats. Results The relative weight of the thyroid in parental LⅠand LⅡ groups were higher than those in the N group at 6 and 9 months [female:(19.67 ± 5.60), (23.81 ± 4.08) vs (10.14 ± 1.20);(22.24 ± 2.06), (33.51 ± 3.24) vs (9.80 ± 1.96);male:(13.0 ± 3.70), (13.84 ± 4.08) vs (5.90 ± 1.20);(14.20 ± 2.67), (19.98 ± 2.84) vs (6.06 ± 0.76), P < 0.05], the females were higher than the males at 3, 6, 9 months (P<0.05). The relative weight of the thyroid in second filial generation LⅠand LⅡgroups were higher than that in the N group at 3, 6 and 9 months (P < 0.05). Except the 6 month LⅠ group, the relative weight of thyroid in the other groups was higher than that in the male (P<0.05). In prolonged iodine-deficiency process, LⅠ and LⅡ groups, the color of the thyroid gland for parental and second filial generation rats appeared darkening, hyperemia and swelling. At the same time, microscopic pathology showed that the thyroid gland of different generations showed increased follicles and smaller follicular cavities. Epithelial cell hyperplasia and interstitial fibrosis and interstitial inflammatory cell infiltration at the end of 9 months were observed. At 3, 6, and 9 months after low iodine, the expression of NIS protein in the LⅠ and LⅡ parental and second filial generation rats was higher than that in the N group (P<0.05). Conclusions Long-term low iodine in different levels of feed can cause compensatory thyroid enlargement and hyperplasia in both parental and offspring rats, the expression of NIS protein has continued to rise.

Expression of Sodium-Iodide Symporter Depending on Mutational Status and Lymphocytic Thyroiditis in Papillary Thyroid Carcinoma

BACKGROUND AND OBJECTIVES: Sodium-iodine symporter (NIS) is a marker for the degree of differentiation in thyroid cancer. The genetic factors or microenvironment surrounding tumors can affect transcription of NIS. In this study, we investigated the NIS mRNA expression according to mutational status and coexistent lymphocytic thyroiditis in papillary thyroid cancer (PTC). MATERIALS AND METHODS: The RNA expression levels of NIS in the samples from database of The Caner Genome Atlas (TCGA; n=494) and our institute (n=125) were analyzed. RESULTS: The PTCs with the BRAFV600E mutation and the coexistence of BRAFV600E and TERT promoter mutations showed significantly lower expression of NIS (p < 0.001, respectively), and those with BRAF-like molecular subtype also had reduced expression of NIS (p < 0.001). NIS expression showed a positive correlation with thyroid differentiation score (r=0.593, p < 0.001) and negative correlations with expressions of genes involved in ERK signaling (r=−0.164, p < 0.001) and GLUT-1 gene (r=−0.204, p < 0.001). The PTCs with lymphocytic thyroiditis showed significantly higher NIS expression (p=0.013), regardless of mutational status. CONCLUSION: The NIS expression was reduced by the BRAFV600E mutation and MAPK/ERK pathway activation, but restored by the presence of lymphocytic thyroiditis.

Iodine Symporter Targeting with 124I/131I Theranostics.

Theranostics, a modern approach combining therapeutics and diagnostics, is among the most promising concepts in nuclear medicine for optimizing and individualizing treatments for many cancer entities. Theranostics has been used in clinical routines in nuclear medicine for more than 60 y-as 131I for diagnostic and therapeutic purposes in thyroid diseases. In this minireview, we provide a survey of the use of 2 different radioiodine isotopes for targeting the sodium-iodine symporter in thyroid cancer and nonthyroidal neoplasms as well as a brief summary of theranostics for neuroendocrine neoplasms and metastatic castration-refractory prostate cancer. In particular, we discuss the role of 124I-based dosimetry in targeting of the sodium-iodine symporter and describe the clinical application of 124I dosimetry in a patient who had radioiodine-refractory thyroid cancer and who underwent a redifferentiation treatment with the mitogen-activated extracellular signal-related kinase kinase inhibitor trametinib.

Assessment of an engineered endothelium via single-photon emission computed tomography.

The clinical translation of cell-based therapeutics often requires highly sensitive, non-invasive imaging tools to assess cell function and distribution in vivo. The objective of this research was to determine whether human Sodium-Iodide Symporter (hNIS) ectopic expression in endothelial cells (ECs) in combination with single-photon emission computed tomography (SPECT) is a feasible approach to non-invasively monitor the presence and viability of an engineered endothelium on expanded polytetrafluoroethylene (ePTFE). Human umbilical vein endothelial cells (HUVECs) were transduced with pLL3.7-hNIS via lentivirus with multiplicity of infection (MOI) of 0, 2, 5, and 10 (n = 4). Ectopic expression of hNIS in HUVECs via optimized lentiviral transduction (MOI 5) enabled cell uptake of a radioisotope that can be detected by SPECT without affecting endothelial cell viability, oxidative stress, or antithrombogenic functions. The viability and distribution of an engineered endothelium grown on ePTFE coated with the biodegradable elastomer poly(1, 8 octamethylene citrate) (POC) and exposed to fluid flow was successfully monitored non-invasively by SPECT. We report the feasibility of a non-invasive, highly sensitive and functional assessment of an engineered endothelium on ePTFE using a combination of SPECT and X-ray computed tomography (SPECT/CT) imaging and hNIS ectopic expression in ECs. This technology potentially allows for the non-invasive assessment of transplanted living cells in vascular conduits. Biotechnol. Bioeng. 2017;114: 2371-2377. © 2017 Wiley Periodicals, Inc.

ATRA increases iodine uptake and inhibits the proliferation and invasiveness of human anaplastic thyroid carcinoma SW1736 cells: Involvement of ß-catenin phosphorylation inhibition.

All-trans-retinoic acid (ATRA) can enhance iodine uptake capability of thyroid tumors, but the mechanisms remain poorly understood. The aim of the present study was to investigate the effects of ATRA on isotope susceptibility, proliferation and invasion of anaplastic thyroid carcinoma (ATC) and potential mechanisms. SW1736 cells were treated with 1 µmol/l ATRA or 1% ethanol for 5 days. A cell line stably expressing ß-catenin-shRNA was established. An iodine uptake assay was performed using 125I. Proliferation and invasiveness were tested using MTT and Transwell assays, respectively. Western blotting was used to assess the expression of ß-catenin, glycogen synthase kinase-3ß (GSK-3ß), sodium/iodine symporter (NIS) and proteins involved in epithelial-mesenchymal transition. Cells pretreated with ATRA were injected subcutaneously into SCID mice. Mice were intraperitoneally injected with 131I once on the first day of treatment, and tumor growth was then assessed. After 35 days of 131I treatment, ATRA-pretreated tumor volume and weight were decreased compared with the 131I alone group (163.32±19.57 vs. 332.06±21.37 mm3; 0.35±0.14 vs. 0.67±0.23 g, both P<0.05). Similar results were observed in the ß-catenin shRNA-pretreated tumors. ATRA also increased the uptake of iodine by SW1736 cells (P<0.01), and similar results were observed in ß-catenin shRNA cells. ATRA treatment decreased the cell proliferation and invasion compared with control cells (all P<0.05), similar to ß-catenin shRNA. ATRA treatment decreased the expression of phosphorylated (p-)ß-catenin, p-GSK-3ß, vimentin, and fibronectin, and increased the expression of NIS and E-cadherin, compared with the control. ATRA increased the iodine uptake and inhibited the proliferation and invasion of SW1736 cells, involving ß-catenin phosphorylation. In conclusion, ATRA could be used to improve the isotope sensitivity of ATC.

Evidence of the Presence of Thyroid Hormones in Achatina fulica Snails

ABSTRACT The objective of this study was to identify thyroid hormones and to examine their putative site of synthesis in Achatina fulica snails. For this purpose, radioimmunoassays were performed for T3 and T4 before and after long starvation with or without hemolymph deproteinization. Sodium/iodide symporter activity in vivo was analyzed through 125I administration with and without KClO4 pretreatment. Only T4 was detected, and its concentration decreased due to starvation or deproteinization. However, high-performance liquid chromatography analysis also showed the presence of T2 and T3 apart from T4, but rT3 was not detected in the A. fulica hemolymph. The sodium/iodide symporter activity was greater in cerebral ganglia than digestive gland, but KClO4 treatment did not inhibit iodide uptake in any of the tissues analyzed. Altogether, our data confirm for the first time the presence of thyroid hormones in A. fulica snails and suggest their participation in the metabolism control in this species, although the putative site of hormone biosynthesis remains to be elucidated.

FoxP3 in papillary thyroid carcinoma induces NIS repression through activation of the TGF-ß1/Smad signaling pathway.

Forkhead box P3 (FoxP3) expression in papillary thyroid carcinoma (PTC) is associated with resistance to radioiodine treatment. The sodium iodine symporter (NIS) is a plasma membrane glycoprotein, the repression of which may render the tumor refractive to radioiodine therapy. In this study, samples from 90 PTCs as well as 40 normal thyroid tissues were examined for FoxP3 and NIS by immunohistochemistry and real-time PCR. We found that FoxP3 was associated with decreased NIS expression. Lentiviral-mediated FoxP3-overexpressing cells were constructed and real-time PCR and western blotting were performed to evaluate the expression of NIS. Meanwhile, key members of the transforming growth factor-ß1 (TGF-ß1) pathway were explored by ELISA and immunofluorescence and a neutralizing TGF-ß1 antibody was used to block activity. In vitro, FoxP3 overexpression significantly reduced NIS transcript and protein levels and the TGF-ß1 pathway was activated. However, treatment with neutralizing TGF-ß1 antibody partially abrogated FoxP3-induced NIS repression. These findings suggest that FoxP3 could compromise NIS expression by inducing TGF-ß1.