Article

Immunohistochemical Analysis of Sodium Iodide Symporter Expression in Metastatic Differentiated Thyroid Cancer: Correlation with Radioiodine Uptake

Division of Endocrinology and Metabolism, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Journal of Clinical Endocrinology & Metabolism (Impact Factor: 6.21). 12/2001; 86(11):5627-32. DOI: 10.1210/jcem.86.11.8048
Source: PubMed

ABSTRACT

The ability of thyroid cancers to concentrate radioiodine (RAI) is dependent, in part, upon the expression and functional integrity of the sodium iodide symporter (NIS). However, some differentiated thyroid carcinomas (DTCs) and most undifferentiated thyroid carcinomas lack the ability to concentrate iodide and are thereby insensitive to 131I therapy. Variation of NIS protein expression may be an important factor in this behavior. We wished to determine whether NIS protein expression in primary DTC tumors correlated with the subsequent RAI uptake by metastatic lesions in the same patients. We obtained paraffin-embedded tissue specimens from 60 patients with metastatic thyroid cancer who had undergone total or near-total thyroidectomy at the Mayo Clinic for DTC and had known presence or absence of RAI uptake in their tumor deposits determined by total body scanning after thyroid hormone withdrawal. Tissue sections from the primary intrathyroidal tumors were subjected to immunostaining (IS) using a monoclonal antibody against human NIS. Slides were subsequently examined for specific IS by two independent reviewers. For each patient, whole body scan (WBS) uptake was recorded, and correlation between results of IS and WBS was analyzed. Of 43 patients with a positive WBS, 37 also had positive IS of their tumors. In six patients with negative IS, a positive WBS was documented, and in three of these cases TSH at the time of surgery was less than 0.3 mIU/liter. Of the 17 patients with negative WBS, 10 were also negative on IS. Positive IS accurately predicted a positive scan in our study in 84% of cases; the ability of the IS to detect all cases with a positive scan was 86%, and it increased to 90% when patients who were receiving thyroid hormone therapy at the time of surgery were excluded from the analysis. Overall, the results of our retrospective study suggest that NIS IS of the thyroidal primary tumor in patients with papillary and follicular thyroid cancers has substantial ability to predict the behavior of subsequent deposits of metastatic and recurrent cancer with respect to iodine trapping and concentration. Our findings require confirmation in prospective studies to more accurately determine the predictive ability of the test and its role in the postoperative management of patients with DTC. If confirmed, NIS IS of DTC primary lesions may prove useful in the management of patients with known or suspected metastatic thyroid cancer.

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Available from: M. Regina Castro, Aug 31, 2015
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    • "When recurrent DTC is suspected because of serum Tg above the cut-off level, several imaging tests may be performed to detect the exact sites of recurrence. The sodium/iodide symporter (NIS) mediates iodide uptake in the thyroid gland and thyroid cancer cells [14]. The ability of the thyroid to accumulate Iodide via NIS is the basis for scintigraphic thyroid imaging with radioiodine (using the gamma-emitting 123I) as well as for therapy using the beta-emitter 131I, which targets and destroys iodide-transporting benign and malignant thyroid cells. "
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    ABSTRACT: Background: After initial treatment of differentiated thyroid carcinoma (DTC) patients are followed with thyroglobulin (Tg) measurements to detect recurrences. In case of elevated levels of Tg and negative neck ultrasonography, patients are treated 'blindly' with Iodine-131 (131I). However, in up to 50% of patients, the post-therapy scan reveals no 131I-targeting of tumor lesions. Such patients derive no benefit from the blind therapy but are exposed to its toxicity. Alternatively, iodine-124 (124I) Positron Emission Tomography/Computed Tomography (PET/CT) has become available to visualize DTC lesions and without toxicity. In addition to this, 18F-fluorodeoxyglucose (18F-FDG) PET/CT detects the recurrent DTC phenotype, which lost the capacity to accumulate iodine. Taken together, the combination of 124I and 18F-FDG PET/CT has potential to stratify patients for treatment with 131I. Methods/design: In a multicenter prospective observational cohort study the hypothesis that the combination of 124I and 18F-FDG PET/CT can avoid futile 131I treatments in patients planned for 'blind' therapy with 131I, is tested.One hundred patients planned for 131I undergo both 124I and 18F-FDG PET/CT after rhTSH stimulation. Independent of the outcome of the scans, all patients will subsequently receive, after thyroid hormone withdrawal, the 131I therapy. The post 131I therapeutic scintigraphy is compared with the outcome of the 124I and 18F-FDG PET/CT in order to evaluate the diagnostic value of the combined PET modalities.This study primary aims to reduce the number of futile 131I therapies. Secondary aims are the nationwide introduction of 124I PET/CT by a quality assurance and quality control (QA/QC) program, to correlate imaging outcome with histopathological features, to compare 124I PET/CT after rhTSH and after withdrawal of thyroid hormone, and to compare 124I and 131I dosimetry. Discussion: This study aims to evaluate the potential value of the combination of 124I and 18F-FDG PET/CT in the prevention of futile 131I therapies in patients with biochemically suspected recurrence of DTC. To our best knowledge no studies addressed this in a prospective cohort of patients. This is of great clinical importance as a futile 131I is a costly treatment associated with morbidity and therefore should be restricted to those likely to benefit from this treatment. Trial registration: Clinicaltrials.gov identifier: NCT01641679.
    Full-text · Article · Jun 2014 · BMC Cancer
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    • "In the present study, the NIS gene was found to be expressed in all but two cases, and its gene expression was higher in the relatively well-differentiated group than in the relatively less differentiated group. Several investigators have reported low NIS gene and protein expression in differentiated thyroid cancers [12, 20, 22–24], and others that papillary cancer tissues display markedly lower and restricted ranges of NIS mRNA expression than normal tissues [12, 20]. Ward et al. [23] identified that patients with papillary thyroid cancer who experienced early recurrence and/or metastasis showed low levels of NIS mRNA expression in the primary tumor. "
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    ABSTRACT: Purpose The expression of glucose transporter-1 (Glut-1) gene and those of major thyroid-specific genes were examined in papillary carcinoma tissues, and the expressions of these genes were compared with cancer differentiation grades. Materials and Methods Twenty-four human papillary carcinoma tissues were included in this study. The expressions of Glut-1- and thyroid-specific genes [sodium/iodide symporter (NIS), thyroid peroxidase, thyroglobulin, TSH receptor and pendrin] were analyzed by RT-PCR. Expression levels were expressed as ratios versus the expression of beta-actin. Pathologic differentiation of papillary carcinoma was classified into a relatively well-differentiated group (n = 13) and relatively less differentiated group (n = 11). Results Glut-1 gene expression was significantly higher in the less differentiated group (0.66 ± 0.04) than in the well-differentiated group (0.59 ± 0.07). The expression levels of the NIS, PD and TG genes were significantly higher in the well-differentiated group (NIS: 0.67 ± 0.20, PD: 0.65 ± 0.21, TG: 0.74 ± 0.16) than in the less differentiated group (NIS: 0.36 ± 0.05, PD: 0.49 ± 0.08, TG: 0.60 ± 0.11), respectively. A significant negative correlation was found between Glut-1 and NIS expression, and positive correlations were found between NIS and TG, and between NIS and PD. Conclusion The NIS, PD and TG genes were highly expressed in well-differentiated thyroid carcinomas, whereas the Glut-1 gene was highly expressed in less differentiated thyroid carcinomas. These findings provide a molecular rationale for the management of papillary carcinoma, especially in the selection of FDG PET or radioiodine whole-body scan and I-131-based therapy.
    Full-text · Article · Jun 2014
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    • "NIS-mediated iodide uptake from the circulating bloodstream into the thyroid follicular cells is the first step for the synthesis of iodine-containing thyroid hormones and is the molecular basis for targeted radioiodine ablation of residual thyroid tissue and treatment of recurrent or metastatic thyroid cancer after thyroidectomy. However, about 20% of patients with differentiated thyroid tumors and nearly all patients with poorly differentiated thyroid tumors fail to respond to radioiodine therapy in part due to decreased NIS expression/function (Caillou et al. 1998, Castro et al. 2001, Patel et al. 2002). Thus, it is of clinical importance to investigate NIS modulation by various pharmacological agents with the objective to increase/restore NIS expression/function for better efficacy of radioiodine therapy. "
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    ABSTRACT: The selective increase of Na(+)/I(-) symporter (NIS)-mediated active iodide uptake in thyroid cells allows the use of radioiodine I(131) for diagnosis and targeted treatment of thyroid cancers. However, NIS-mediated radioiodine accumulation is often reduced in thyroid cancers due to decreased NIS expression/function. As PI3K signaling is overactivated in many thyroid tumors, we investigated the effects of inhibitors for PI3K, Akt, or mTORC1 as well as their interplay on NIS modulation in thyroid cells under chronic TSH stimulation. PI3K inhibition by LY294002 increased NIS-mediated radioiodide uptake (RAIU) mainly through upregulation of NIS expression, however, mTORC1 inhibition by Rapamycin did not increase NIS-mediated RAIU despite increased NIS protein levels. In comparison, Akt inhibition by Akti-1/2 did not increase NIS protein levels, yet markedly increased NIS-mediated RAIU by decreasing iodide efflux rate and increasing iodide transport rate and iodide affinity of NIS. The effects of Akti-1/2 on NIS-mediated RAIU are not detected in nonthyroid cells, implying that Akti-1/2 or its derivatives may represent potential pharmacological reagents to selectively increase thyroidal radioiodine accumulation and therapeutic efficacy.
    Preview · Article · Feb 2012 · Endocrine Related Cancer
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