The master role of polarized NIS expression in regulating iodine metabolism in the human body

ABSTRACT Objective: The aim of this study was to investigate how polarized sodium iodide symporter (NIS) expression may regulate iodide metabolism in vivo. Materials and methods: Polarized NIS expression was analyzed in tissues that accumulate iodide by the use of immunohistochemistry and polyclonal antibody against the C-terminal end of human NIS (hNIS). Results: Iodide absorption in the human intestine occurs via NIS expressed in the apical membrane. Iodide is secreted into the lumen of the stomach and salivary glands via NIS expressed in the basolateral membrane and then circulates back from the small intestine to the bloodstream via NIS expressed in the apical membrane. Conclusion: Polarized NIS expression in the human body regulates intestinal-bloodstream recirculation of iodide, perhaps prolonging the availability of iodide in the bloodstream. This leads to more efficient iodide trapping by the thyroid gland. Understanding the regulation and manipulating gastrointestinal iodide recirculation could increase radioiodine availability during theranostic NIS applications.

Research Progress on Pathogenic Factors of Breast Cancer Combined with Thyroid Cancer / 肿瘤防治研究

Thyroid cancer and breast cancer are two of the most common malignant tumors in women. Concurrent tumors of the thyroid and breast are relatively rare in clinical practice; however, the incidence of such dual malignancies has recently increased. Researches conducted in the past mainly focused on the possible increase in the incidence of contralateral breast cancer, while the increased risk of synchronized thyroid cancer in women with breast cancer has attracted widespread attention recently. The specific mechanism has not been fully understood. This article reviews the pathogenic factors between these two diseases, and evaluates the etiological role of these factors in these double primary cancers, so as to provide a better basis for clinical practice.

Total synthesis of D-glycero-D-mannno-heptose 1β, 7-bisphosphate with 3-O-amyl amine linker and its monophosphate derivative / 中国天然药物

D-Glycero-D-mannno-heptose 1β, 7-bisphosphate (HBPβ) is an important intermediate for constructing the core structure of Gram-negative bacterial lipopolysaccharides and was reported as a pathogen-associated molecular pattern (PAMP) that regulates immune responses. HBPβ with 3-O-amyl amine linker and its monophosphate derivative D-glycero-D-mannno-heptose 7-phosphate (HP) with 1α-amyl amine linker have been synthesized as candidates for immunity study of HBPβ. The O3-amyl amine linker of heptose was installed by dibutyltin oxide-mediated regioselective alkylation under fine-tuned protecting condition. The stereoselective installation of 1β-phosphate ester was achieved by NIS-mediated phosphorylation at low temperature. The strategy for installation of 3-O-amyl amine linker onto HBP derivative can be expanded to the syntheses of other conjugation-ready carbohydrates bearing anomeric phosphoester.

Sodium Iodide Symporter (NIS) in the Management of Patients with Thyroid Carcinoma / 대한핵의학회잡지

Although radioiodine has been applied in thyroid diseases including carcinoma for over 70 years, it was only in 1996 that the basic molecular mechanism of iodine uptake was identified. Iodide is actively transported into the thyroid via a membrane glycoprotein known as sodium iodide symporter (NIS). NIS mediates radioiodine uptake into thyroid normal and cancer cells. The knowledge on NIS expression has provided scientific background to the empirical management of thyroid carcinoma. Based on recent studies of the NIS gene, this paper provides current clinical applications and future studies.

Expression of sodium iodide symporter mRNA and its clinical significance in differentiated thyroid carcinoma / 西安交通大学学报(医学版)

Objective To investigate the expression of sodium iodide symporter (NIS ) mRNA in differentiated thyroid Carcinoma (DTC)and further explore its value in clinical diagnosis and therapy of DTC. Methods The expression of NIS mRNA was detected and analyzed in 21 nodular goiter and 45 cases of DTC (including 35 cases of papillary thyroid carcinoma and 10 cases of follicular thyroid carcinoma)by using real-time fluorescent quantitative reverse transcription polymerase chain reaction (real-time RT-PCR).Results Compared with that in nodular goiter,the mRNA expression of NIS in DTC tissue was significantly decreased (P < 0.05 ). Moreover,the mRNA expression of NIS was significantly correlated with lymph node metastasis and AJCC stage, respectively.The expression of NIS mRNA in DTC with lymph node metastasis was significantly decreased compared with that in DTC without lymph node metastasis (P <0.05).In addition,the expression of NIS mRNA in Ⅱ-Ⅳstage DTC was significantly decreased compared with that in Ⅰ - Ⅱ stage DTC (P < 0.05 ).Conclusion Differential expression of NIS can provide evidence for individual 1 3 1 I therapy for DTC.

The correlation among hMLH1, NIS and TSHR genes with promoter methylation in papillary thyroid carcinoma and its clinical significance / 肿瘤

Objective: To investigate the aberrant methylation status of hMLH1 (human mutL homologue 1) gene in PTC (papillary thyroid carcinoma) tissues, and its correlations with the aberrant methylation of NIS (sodium iodide symporter) and TSHR (thyroid-stimulating hormone receptor) genes. Methods: qMSP (quantitative methylation-specific PCR) was carried out to detect the promoter methylation status of hMLH1, NIS and TSHR genes in PTC tissues and adjacent normal thyroid tissues from 152 patinets with PTC. The correlation between the clinicopathologic characteristics and the promoter methylation status of hMLH1 gene was analyzed. The relationships among the methylation status of hMLH1, NIS and TSHR genes and their independent or synergistic effects on the progression of PTC were investigated. Results: The promoter methylation rate of hMLH1 gene in PTC tissues (37.5%) was significantly higher than that in the adjacent normal thyroid tissues (5.3%) (P 0.05). There was a weak correlation among aberran promoter methylation of hMLH1, NIS and TSHR genes (r 0.05). Conclusion: The aberrant methylation of hMLH1 gene promoter in PTC tissues might be associated with the progression of the tumor. There exists no correlation among the aberrant methylation of hMLH1, NIS and TSHR genes, and their independent or synergistic effect also may not be associated with the progression of PTC. Copyright © 2013 by TUMOR.

The Effect of Atorvastatin and Simvastatin on NIS Expression of the TPC-1 Cell under the Therapeutic Blood Concentrations

BACKGROUND: Although so many experimental trials have been done to improve the redifferentiation and responsiveness of radioiodide therapy, they have not yet yielded any satisfactory results. As statins inhibit both farnesylation and geranylgeranylation, they have been reported to have an antineoplastic and redifferentiation effect in experimental and clinical studies. In this study, we investigated the relationship between statins and the alteration of the NIS expression and, TPC-1 cell apotosis to evaluate the possibility of using statins as adjuvant therapeutic agents for papillary thyroid cancer. METHODS: We used the TPC-1 cell lines for our experiments. Cell viabilities were measured by CCK-8. The degrees of apoptosis and, the expressions of NIS mRNA and NIS protein were measured by flow cytometry, semi quantitative RT-PCR and Western blot assay. RESULTS: Increased levels of NIS mRNA and NIS protein were observed under therapeutic blood concentrations (concentrations of simvastatin: 20, 50, 80 nM, concentrations of atorvastatin: 50, 80,110 nM), but the dose-response relationship was only manifested within simvastatin. The TPC-1 cells showed a concentration dependent decrease of viability and an increase of apoptosis not under therapeutic blood concentrations, but under excessively high concentrations (after treatment with 10-50 microM of atorvastatin and with 1-10 microM of simvastatin). CONCLUSION: The results of this study show that effective therapeutic blood concentrations of simvastatin and atorvastatin can give a favorable effect on the NIS expression under effective therapeutic blood concentrations. Therefore, we demonstrated the possibility that simvastatin and atorvastatin might have an important role as adjuvant therapeutic agents to improve the responsiveness of radioiodide therapy for papillary thyroid cancer. Further studies are needed to clarify this issue.

Effects of fluoride on the expression of functional genes related with the metabolism of thyroid hormone in FRTL cells / 中国兽医学报

To investigate the effects of fluoride on the expression of thyroglobulin (TG),thyroid peroxidase(TPO),odium iodide symporter (NIS) genes in FRTL cells,FRTL cells cultured in vitro were treated in logarithmic phase with sodium fluoride at different concentration of 20.0,10.0,5.0,2.5,1.25 mg/L,respectively.After 72 h,the cells were collected and semi-quantitative RT-PCR for TG mRNA,TPO mRNA and NIS mRNA and β-actin was performed.The results showed that compared with the control cells,the expression levels of TG gene in FRTL cells treated with lower concentration of sodium fluoride increased compensatively,but decreased significantly (P<0.05) with higher concentration(>5.0 mg/L);the RT-PCR products of TPO and NIS in FRTL cells treated with all concentration of sodium fluoride reduced,some of them were significant (P<0.05).It is concluded that fluoride can reduce the expression of TG,TPO,NIS genes in thyroid cells,conseguently cause dysfunction" of thyroid in uptaking and unilizing of iodine,and synthesizing,storing,secreting of thyroid hormones.

Seven-year follow-up of a juvenile female with papillary thyroid carcinoma with poor outcome, BRAF mutation and loss of expression of iodine-metabolizing genes / Sete anos de seguimento de uma paciente jovem com carcinoma papílfero de tireóide e mutação de BRAF e perda de expressão de genes do metabolismo de iodo

BACKGROUND: Recent studies reported that BRAF V600E mutation, the most prevalent genetic event found in papillary thyroid carcinoma, is an independent poor prognostic marker. Additionally, it correlates with a less differentiated tumor stage due to reduced expression of key genes involved in iodine metabolism. We previously described a patient with BRAF V600E mutation in primary tumor and a new mutation (V600E+K601del) in the matched-lymph node metastases. In the present study we report an unusual clinical behavior of PTC and correlate with BRAF mutational status and level of expression of TSHR and NIS. METHODS: Quantitative PCR (qPCR) was used to evaluate the NIS and TSHR level of expression in matched papillary thyroid carcinoma and adjacent normal tissue. RESULTS: In this study, we presented a seven-year follow up of a juvenile papillary thyroid carcinoma patient who had an aggressive tumor harboring BRAF mutation, and failed to conventional therapy. We found a markedly decrease of NIS and TSHR expression in primary PTC compared to adjacent normal thyroid tissue. CONCLUSION: Our findings suggest that BRAF mutational status and decreased NIS and TSHR expression in this patient may reduce radioiodine uptake and lead to a negative response to radioiodine therapy.

INTRODUÇÃO: Estudos recentes demonstraram que a mutação V600E no gene BRAF é o evento genético mais freqüentemente encontrado em carcinoma papilífero da tiróide e um marcador de prognóstico independente. Adicionalmente, esta alteração genética tem sido correlacionada com a redução de expressão de genes envolvidos no metabolismo do iodo. Previamente, nosso grupo descreveu uma paciente com a mutação V600E no gene BRAF no tumor primário e uma mutação nova (V600E+K601del) em metástases pareadas. Neste estudo, reportamos um carcinoma papilífero com um comportamento clínico incomum e correlacionamos com a presença de mutação no gene BRAF e os níveis de expressão de TSHR e NIS. MÉTODO: Análise de expressão dos genes NIS e receptor de TSH (TSHR) através da técnica de PCR em tempo real. RESULTADOS: Descrevemos sete anos de acompanhamento de uma paciente jovem que apresentava um tumor com comportamento agressivo e baixa resposta aos tratamentos convencionais. Uma acentuada diminuição da expressão do TSHR e a ausência de expressão de NIS foram observadas no tumor primário desta paciente quando comparada com o tecido tiroidiano normal adjacente. CONCLUSÃO: Nossos dados sugerem que as mutações encontradas nesta paciente no gene BRAF com conseqüente perda de expressão dos genes NIS e TSHR podem ter reduzido a captação de iodo radioativo e a resposta ao tratamento.

The Antiproliferative and Redifferentiative Effects of Na-4-Phenylbutyrate in Human Thyroid Cancer Cell Lines

PURPOSE: Sodium-4-phenylbutyrate (Na-4-PB) is an analogue of phenylacetate, which is a well-known redifferentiating agent. In vitro and in vivo studies on this agent have been done and the clinical relevance of Na-4-PB has been studied in other malignancies, but not in thyroid cancer. We investigated the effect of Na-4-PB on cell proliferation and differentiation in thyroid cancer cell lines. METHODS: We used 5 thyroid cancer cell lines: TPC-1, FTC-133, FTC-236, FTC-238 and XTC-1. MTT assay and flowcytometry were used to measure the agent's antiproliferative effects and the cell cycle change. We evaluated the PPARgamma expression via western blotting and the mRNA expressions of NIS, Tg and CD 97 were determined by performing RT-PCR. Troglitazone, a potent PPARgamma agonist, was used in combined treatment with Na-4-PB. RESULTS: Na-4-PB inhibited cell proliferation in a dose and time dependent manner in all 5 thyroid cancer cell lines. By performing flowcytometry in the FTC-133 and TPC-1 cell lines, we identified that the antiproliferative effect of Na-4-PB was associated with an increased apoptotic cell population. Treatment with Na-4-PB upregulated the PPARgamma expression, but the combined treatment of Na-4-PB with troglitazone did not seem to be synergistic for the antiproliferative effect. Treatment with Na-4-PB downregulated the CD97 mRNA expression and it upregulated the NIS and Tg mRNA expressions in both the FTC-133 and TPC-1 cell lines. CONCLUSION: Na-4-PB inhibited thyroid cancer cell proliferation by inducing apoptosis in a dose dependent manner. Treatment with Na-4-PB increased the expression of PPARgamma and it upregulated such differentiation markers as NIS and Tg, and it downregulated CD97, a dedifferentiation marker. Na-4-PB should be further evaluated as a new potential therapeutic agent for patients with thyroid cancer.

The importance of sodium/iodide symporter (NIS) for thyroid cancer management

The thyroid gland has the ability to uptake and concentrate iodide, which is a fundamental step in thyroid hormone biosynthesis. Radioiodine has been used as a diagnostic and therapeutic tool for several years. However, the studies related to the mechanisms of iodide transport were only possible after the cloning of the gene that encodes the sodium/iodide symporter (NIS). The studies about the regulation of NIS expression and the possibility of gene therapy with the aim of transferring NIS gene to cells that normally do not express the symporter have also become possible. In the majority of hypofunctioning thyroid nodules, both benign and malignant, NIS gene expression is maintained, but NIS protein is retained in the intracellular compartment. The expression of NIS in non-thyroid tumoral cells in vivo has been possible through the transfer of NIS gene under the control of tissue-specific promoters. Apart from its therapeutic use, NIS has also been used for the localization of metastases by scintigraphy or PET-scan with 124I. In conclusion, NIS gene cloning led to an important development in the field of thyroid pathophysiology, and has also been fundamental to extend the use of radioiodine for the management of non-thyroid tumors.

A glândula tireóide tem capacidade de captar e concentrar iodeto, etapa fundamental na biossíntese dos hormônios tireóideos. O uso de iodo radioativo para fins de diagnóstico e terapia das doenças da tireóide vem sendo feito há muitos anos. Entretanto, somente após a clonagem do gene que codifica o co-transportador de sódio/iodeto (NIS) houve aumento significativo dos estudos relacionados ao mecanismo de transporte de iodeto. Os estudos sobre a regulação da expressão do NIS e a possibilidade de terapia gênica visando à transferência do gene NIS para células que normalmente não expressam esse transportador, foram também viabilizados. Na maior parte dos nódulos tireóideos hipofuncionantes, tanto benignos quanto malignos, a expressão do gene do NIS está presente, mas a proteína NIS fica retida no compartimento intracelular. A transferência do gene usando-se promotores tecido-específicos possibilitou a expressão do NIS em células tumorais não-tireóideas in vivo. Além do seu uso terapêutico, o NIS também vem sendo usado para a localização de metástases tumorais através da cintilografia ou do PET-scan usando-se 124I. Em conclusão, a clonagem do NIS possibilitou enorme avanço na área de fisiopatologia tireóidea e foi também fundamental para estender o uso do radioiodo para tumores não tireóideos.

TSH signalling and cancer

Thyroid cancers are the most frequent endocrine neoplasms and mutations in the thyrotropin receptor (TSHR) are unusually frequent. Here we present the state-of-the-art concerning the role of TSHR in thyroid cancer and discuss it in light of the cancer stem cell theory or the classical view. We briefly review the gene and protein structure updating the cancer related TSHR mutations database. Intriguingly, hyperfunctioning TSHR mutants characterise differentiated cancers in contrast to undifferentiated thyroid cancers which very often bear silenced TSHR. It remains unclear whether TSHR alterations in thyroid cancers play a role in the onset or they appear as a consequence of genetic instability during evolution, but the presence of functional TSHR is exploited in therapy. We outline the signalling network build up in the thyrocyte between TSHR/PKA and other proliferative pathways such as Wnt, PI3K and MAPK. This networks integrity surely plays a role in the onset/evolution of thyroid cancer and needs further research. Lastly, future investigation of epigenetic events occurring at the TSHR and other loci may give better clues for molecular based therapy of undifferentiated thyroid carcinomas. Targeted demethylating agents, histone deacetylase inhibitors combined with retinoids and specific RNAis may help treatment in the future.

Os cânceres de tiróide são as neoplasias endócrinas mais frequentes e as mutações no receptor de tirotrofina (TSHR) são incomumente frequentes. Nesta revisão nós apresentamos o "estado da arte" com relação ao papel do TSHR no câncer de tiróide e o discutimos à luz da teoria da célula matriz do câncer ou a visão clássica. Revisamos brevemente a estrutura do gene e da proteína, atualizando a base de dados das mutações do TSHR relacionadas ao câncer. Curiosamente, mutações do TSHR com hiperfunção caracterizam cânceres diferenciados, em contraste com os cânceres de tiróide indiferenciados, os quais muito comumente mostram TSHR silenciados. Permanece obscuro se as alterações do TSHR em cânceres de tiróide têm algum papel no surgimento ou se elas aparecem como conseqüência da instabilidade genética durante seu desenvolvimento, mas a presença de TSHR funcional é explorada na terapia. Nós delineamos a rede de sinalizacão desenvolvida no tirócito entre TSHR/PKA e outras vias proliferativas como a Wnt, PI3k e MAPK. A integridade desta rede certamente tem um papel no surgimento/evolução do câncer de tiróide e necessita de novas pesquisas. Finalmente, novas investigacões sobre os eventos epigenéticos que ocorrem no TSHR e outros locais poderão trazer novas informações para uma terapia de base molecular nos carcinomas indiferenciados de tiróide. Agentes demetilantes direcionados, inibidores da histona-deacetilase, combinados com retinóides e RNAs específicos poderão auxiliar no tratamento futuro.

Establishment of a Hepatocellular Carcinoma Cell Line Expressing Dual Reporter Genes: Sodium Iodide Symporter (NIS) and Enhanced Green Fluorescence Protein (EGFP) / 핵의학분자영상

PURPOSE: Dual reporter gene imaging has several advantages for more sophisticated molecular imaging studies such as gene therapy monitoring. Herein, we have constructed hepatoma cell line expressing dual reporter genes of sodium iodide symporter (NIS) and enhanced green fluorescence protein (EGFP), and the functionalities of the genes were evaluated in vivo by nuclear and optical imaging. MATERIALS AND METHODS: A pRetro-PN vector was constructed after separating NIS gene from pcDNA-NIS. RSV-EGFP-WPRE fragment separated from pLNRGW was cloned into pRetro-PN vector. The final vector expressing dual reporter genes was named pRetro-PNRGW. A human hepatoma (HepG2) cells were transfected by the retrovirus containing NIS and EGFP gene (HepG2-NE). Expression of NIS gene was confirmed by RT-PCR, radioiodine uptake and efflux studies. Expression of EGFP was confirmed by RT-PCR and fluorescence microscope. The HepG2 and HepG2-NE cells were implanted in shoulder and hindlimb of nude mice, then fluorescence image, gamma camera image and I-124 microPET image were undertaken. RESULTS: The HepG2-NE cell was successfully constructed. RT-PCR showed NIS and EGFP mRNA expression. About 50% of cells showed fluorescence. The iodine uptake of NIS-expressed cells was about 9 times higher than control. In efflux study, T(1/2) of HepG2-NE cells was 9 min. HepG2-NE xenograft showed high signal-to-background fluorescent spots and higher iodine-uptake compared to those of HepG2 xenograft. CONCLUSION: A hepatoma cell line expressing NIS and EGFP dual reporter genes was successfully constructed and could be used as a potential either by therapeutic gene or imaging reporter gene.

Influence of the estradiol on the thyroid iodine uptake and the expression of NIS in the thyroid gland of rats / 基础医学与临床

Objective To identify the impact of estradiol on the goiter and the function of the thyroid gland with different dosages of estradiol.Methods 48 Wistar rats(female,normal state) were divided into 4 groups: Ⅰ,ovx,Ⅱ,sham;Ⅲ,ovx+E_(2)-low and Ⅳ ovx +E_(2)-large.In each group,we applied nuclide scanning of()~(131)I and()~(99)mTcO4 to detect the thyroid iodine uptake and adopted the technique of RT-PCR to test the expression of NIS.Quantity of TSH、FT_(3)、FT_(4) and the estradiol were examined.Results The expression of NIS was inhibited in group Ⅰ and group Ⅳ.Conclutions Estradiol can enhance the capability of the thyroid glands uptaking iodine and inhibit the expression of NIS and so estradiol is a very important component in the pathogenesis of goiter.

Effect of High Concentration of Estradiol on Thyroid Specific Genes Expression and Cell Growth / 대한내분비학회지

BACKGROUND: Since various thyroid diseases have dominant prevalence in women, it has been suggested that female sex hormone have important role on thyroid cell physiology. Interestingly, many thyroid disorders are newly diagnosed or changed their course around the period of high estrogen status, such as pregnancy. In this study, we questioned whether high concentration of estrogen could modulate thyroid cell function. METHODS: We treated normal rat thyroid FRTL-5 cell line with different time and concentration of estradiol. Using cell count, FACscan, and Northern blot analysis, we compared the changes of cell growth, cell cycle progression and thyroid specific genes expression. To evaluate the influence of thyroid stimulating hormone (TSH), all experiment was designed as two different sets, with (6H) or without TSH (5H). RESULTS: The concentration of 10-1000 nM estradiol had definite stimulatory function on thyroid cell growth in 5H condition as concentration dependent manner. FACscan revealed the increased cell growths were related to G1/S progression. The Pax-8, TTF-1 and NIS gene expressions were dramatically increased in 10-1000 nM of estradiol, too. With TSH (6H), however, we could not find any cell growth stimulating effects with 10-1000 nM of estradiol. CONCLUSION: High concentration of estradiol is one of important control factor for thyroid growth and thyroid specific genes expression, especially in 5H condition. It indicate that exposure to high concentration of female sex hormone, such as pregnancy, can be a direct stimulating factor to various thyroid function and related to autoimmune or nodular thyroid diseases around the period of pregnancy.

Comparison of Na+/I- Symporter Expression Rate in Malignant and Benign Thyroid Diseases: Immunohistochemical Study / 핵의학분자영상

PURPOSE: Previous studies have not showed consistent results for the level of expression of sodium/iodide symporter (NIS) in thyroid diseases, especially malignant tumor. We undertook this study to evaluate the distribution of NIS expression in malignant thyroid diseases and compare with that in benign thyroid disease. MATERIALS AND METHODS: Total patients were 119 cases (Men 15, 48+/-13 yrs). Total number of samples were 205 pieces. In malignant thyroid disease, there were 153 samples: 90 in papillary carcinoma, 4 in follicular carcinoma, 2 in medullary carcinoma and 57 in metastatic lymph node. In benign thyroid disease, there were 52 samples: 36 in goiter/cyst, 11 in thyroiditis and 5 in follicular adenoma. Using immunohistochemical methods, we probed 205 samples with monoclonal anti-NIS Ab. Grading of staining was scored as 0 (negative or absent), 1 (weakly positive), 2 (moderately positive) or 3 (strongly positive). Expression rate (ER) of NIS positivity in individual disease entity was expressed as percentage of total number divided by number in 2 plus 3 grade. RESULTS: ERs of malignant thyroid diseases were 63% in papillary carcinoma, 81% in metastatic lymph node, 71% in follicular carcinoma and 100% in medullary carcinoma. ERs of benign thyroid disease were 53% in goiter/cyst, 64% in thyroiditis and 40% in follicular adenoma. ER of malignant thyroid diseases was higher than benign thyroid diseases (71% vs 54%). Grading of NIS expression in papillary carcinoma or goiter/cyst was heterogeneously distributed in considerable cases. Normal tissue also showed heterogeneous distribution of NIS expression, which was not correlated with that of primary lesion. CONCLUSION: In papillary thyroid carcinoma, distribution of NIS expression was heterogeneous and increased, and not different compared with that of benign thyroid disease.

Molecular Imaging Using Sodium Iodide Symporter (NIS) / 대한핵의학회잡지

Radioiodide uptake in thyroid follicular epithelial cells, mediated by a plasma membrane transporter, sodium iodide symporter (NIS), provides a first step mechanism for thyroid cancer detection by radioiodide injection and effective radioiodide treatment for patients with invasive, recurrent, and/or metastatic thyroid cancers after total thyroidectomy. NIS gene transfer to tumor cells may significantly and specifically enhance internal radioactive accumulation of tumors following radioiodide administration, and result in better tumor control. NIS gene transfers have been successfully performed in a variety of tumor animal models by either plasmid-mediated transfection or virus (adenovirus or retrovirus) -mediated gene delivery. These animal models include nude mice xenografted with human melanoma, glioma, breast cancer or prostate cancer, rats with subcutaneous thyroid tumor implantation, as well as the rat intracranial glioma model. In these animal models, non-invasive imaging of in vivo tumors by gamma camera scintigraphy after radioiodide or technetium injection has been performed successfully, suggesting that the NIS can serve as an imaging reporter gene for gene therapy trials. In addition, the tumor killing effects of I-131, ReO4-188 and At-211 after NIS gene transfer have been demonstrated in in vitro clonogenic assays and in vivo radioiodide therapy studies, suggesting that NIS gene can also serve as a therapeutic agent when combined with radioiodide injection. Better NIS-mediated imaging and tumor treatment by radioiodide requires a more efficient and specific system of gene delivery with better retention of radioiodide in tumor. Results thus far are, however, promising, and suggest that NIS gene transfer followed by radioiodide treatment will allow non-invasive in vivo imaging to assess the outcome of gene therapy and provide a therapeutic strategy for a variety of human diseases.

The Expression of NIS and Pendrin in Thyroid Cancer Tissues with Real Time RT-PCR / 대한내분비외과학회지

PURPOSE: It has not been clearly investigated how iodine can be trapped from the extracellular space into thyroid follicular cells, the defective iodide-trapping mechanism appears to be an early and constant feature during oncogenic transformation of thyroid cells. In recent studies, NIS and pendrin are associated with the trapping process. Thus, in order to reveal this uncertain relationship, each of the quantitative expressions of NIS and pendrin in various thyroid tissues were evaluated by real time RT-PCR. METHODS: This study included 63 patients who had undergone thyroidectomy in Uijongbu St. Mary's hospital from Jan. 2000 to Jan. 2003. 13 cases of normal thyroid, 17 cases of hypofunctioning thyroid adenomas, and 33 cases of thyroid cancer were examined. The thyroid cancer group was further divided into high and low risk group according to the AMES score, and the NIS and pendrin levels were compared between the two groups. Real time RT-PCR was conducted with the extracted RNAs, using GAPDH as the control. RESULTS: As for pendrin, its expression was decreased by 7% in the thyroid adenoma group compared with that of normal thyroid, while there was a 59% decrease in thyroid cancer cases. NIS expression was decreased by 20% in the thyroid adenoma group, and a 40% decrease was found in thyroid cancer group. Due to the impediment of pendrin in both high and low risk group of thyroid cancer, there was a 19% decrease in the high risk group compared with the low risk group. As for the impediment of NIS in the high risk group, an increase of 30% was found. However, no statistical significance was shown (P=0.344 vs P=0.688). CONCLUSION: According to this study, it can be inferred that the decrease in the expressions of NIS and pendrin are related to tumorigenesis of thyroid cancer. Also, further research is needed to reveal the cause of genetic transformation, as well as the value of utilization of NIS and pendrin as tumor markers.

Factors Associated with Expression of Sodium/iodide Symporter (NIS) mRNA in Breast Cancer / 한국유방암학회지

PURPOSE: Cells of mammary gland as well as breast cancer uptake iodide through sodium/iodide symporter (NIS). The pathophysiologic importance of NIS is not evaluated well. The purpose of this study is to find relationships between the expression of NIS and other findings of breast cancer including ER, PR, C-erbB2, topoisomerase IIa, p53, and histologic grade of breast cancer. METHODS: Fresh frozen specimens from 21 female breast cancer patients (mean age 50 13 years) with breast cancer were examined by RT-PCR for NIS mRNA. Immunohistochemical staining for ER, PR, C-erb B2, topoisomerase IIa and p53. Staging and degree of differentiation of cancer cells were also performed to evaluate the biological behavior of breast cancer. RESULTS: NIS mRNA was expressed in 90% of the evaluated breast cancer tissues. The mean semiquantitative value of NIS mRNA in PR positive group was 2.02+/-0.35, which was higher than that of PR negative group (1.11+/-0.18; P=0.001). ER positive group showed higher value of NIS mRNA (2.02+/-0.35) than ER negative group (1.19+/-0.63; P=0.002). In addition, NIS mRNA values was significantly different according to differentiation of cancer cells (well differentiated type, 2.20+/-0.37 vs. less differentiated type, 1.39+/-0.63, P=0.01). However, there was no significant association between NIS mRNA levels and the other biologic characteriscs such as C-erb B2, topoisomerase IIa, and p53. CONCLUSION: The results showed that the expression of NIS in breast cancer may be associated with the presence of PR and ER as well as the degree of differentiation of breast cancer cells.

Effect of LiCl on Iodine Kinetics in Thyroid Cancer Cell Lines Transduced by Recombinant Adenovirus Containing Sodium Iodide Symporter(NIS) Gene / 대한내분비학회지

BACKGROUND: Lithium is known to increase the retention of iodide in the thyroid gland, or in well differentiated thyroid cancer tissue. The effects of lithium on the function of the sodium iodide symporter (NIS) protein, especially when the lithium is increased in the retention of iodide in NIS-producing cells, the effect of lithium, on the kinetics of undifferentiated thyroid cancer cells transduced by a recombinant adenovirus containing the NIS gene, were checked. METHOD: Human NIS cDNA was inserted into pAxCAwt, a recombinant adenoviral cosmid vector, where the E1 & E2 genes have been deleted, making Rad-hNIS, which was propagated in 293 cells. The iodide uptake was evaluated by the 125I uptake assay in the undifferentiated thyroid cancer cells, ARO, FRO and NPA, following the infection with Rad-hNIS (1 or 10 MOI) in the presence, or absence, of LiCl at optimized concentrations. The iodide efflux was evaluated by the 125I efflux assay, for 1 hour, in the same cells expressing the NIS in the presence, or absence, of LiCl. Similar experiments were performed in the normal thyroid cell line, FRTL-5, cultured in 6H5 media. RESULTS: LiCl, at concentrations over 1.0mM, caused a significant decrease in the cell viability, as evaluated by trypan blue dye exclusion, in a dose dependent manner. When infected with Rad-hNIS, the iodide uptake was not affected by the LiCl in the ARO or NPA cells. However, LiCl(0.1and 1.0mM) increased the iodide uptake by 50 to 100%(vs. control) in the Rad-hNIS transduced FRO cells. In the Rad-hNIS transduced FRO cells, the iodide was released rapidly from the cells, with only 20.7+/-4.8% of the iodide uptake remaining at 1 hour, which was no different in the presence of LiCl (24.5+/-7.9%). The iodide efflux was not affected by the LiCl in the FRTL-5 cells cultured in the presence of TSH. CONCLUSION: These results suggest that the lithium-induced iodide retention in the thyroid gland, or in well differentiated thyroid cancer tissue, is not caused by the effect of the lithium on the NIS function, or the function of proteins or channels, involved in iodide transport via cell membranes. Although the iodide uptake can be markedly increased by the expression of NIS, with the transduction of Rad-hNIS, in undifferentiated thyroid cancer cells, the iodide taken up is rapidly released from the cells. A method for inducing the iodide retention in the cell should be elucidated in order to render the NIS gene therapy effective.