Expression of pendrin and NIS iodide transporters in human breast tumor and peri-tumoral tissue.

Introduction: Thyroid iodide transporters, Na+/I- symporter (NIS) and pendrin (PDS), are responsible for supplying this vital micronutrient for thyroid hormone synthesis by thyroid peroxidase (TPO). Both proteins were shown to be expressed, apart from the thyroid, also in other human tissues, including lactating mammary gland. NIS expression in human breast cancers has been widely studied. On the other hand, until now PDS mRNA levels in breast tumor tissue have been estimated only in high throughput analyses. Previously, we have observed that TPO is expressed in normal and cancerous human breast tissues and shows enzymatic activity. However, biochemical activity of TPO in human breast cancer cells requires iodide transport by NIS and PDS. Therefore, to extend our previous study on TPO expression and function in human breast tumors we performed analysis of NIS and PDS levels in the same group of patients. Material and methods: The study involved detection of NIS and PDS protein levels by immunohistochemistry and Western blotting, as well as mRNA levels by real-time quantitative polymerase chain reaction. Results: Here we provide direct evidence that NIS and PDS are expressed in human breast cancer tissue, with NIS levels being increased and PDS levels decreased in tumor tissue. Interestingly, PDS mRNA levels in breast cancer tissue seem to be influenced by the estrogen receptor status and age of the patients, while NIS mRNA levels were dependent on histological type of the tumor. Conclusions: This study provides valuable information important for consideration in diagnostic or therapeutic application of radioiodine in breast cancer management.

Thyroid peroxidase (TPO) expressed in thyroid and breast tissues shows similar antigenic properties.

BACKGROUND: Thyroid peroxidase (TPO) is essential for physiological function of the thyroid gland. The high prevalence of thyroid peroxidase antibodies (TPOAbs) in patients with breast cancer and their protective role had previously been demonstrated, indicating a link between breast cancer and thyroid autoimmunity. Recently, TPO was shown to be present in breast cancer tissue samples but its antigenicity has not been analyzed. METHODS: In this study, we investigated TPO expression levels in a series of fifty-six breast cancer samples paired with normal (peri-tumoral) tissue and its antigenic activity using a panel of well-characterized murine anti-human TPOAbs. RESULTS: We have shown that TPO transcripts were present in both normal and cancer tissue samples, although the amounts in the latter were reduced. Additionally, we observed that TPO levels are lower in more advanced cancers. TPO protein expression was confirmed in all tissue samples, both normal and cancerous. We also found that the antigenicity of the immunodominant regions (IDRs) in breast TPO resembles that of thyroid TPO, which is crucial for effective interactions with human TPOAbs. CONCLUSIONS: Expression of TPO in breast cancer together with its antigenic activity may have beneficial effects in TPOAb-positive breast cancer patients. However, further studies are needed to confirm the beneficial role of TPOAbs and to better understand the underlying mechanism.

Identification of GPR39 receptor and ghrelin receptor in thyroid tissues in paediatric patients with immune and non-immune thyroid diseases.

The preproghrelin gene is responsible for generating ghrelin and obestatin, two gastric peptides with opposite effects on food intake. Obestatin suppresses food intake and digestive motility through interaction with GPR39 (GPCR). Ghrelin is supposed to be a link connecting metabolism and energy homeostasis with growth as the result of activation of the growth hormone secretagogue receptor (GHSR).The aim of the current study was to assess the expression of preproghrelin, GPR39 and GHSR in thyroid tissues from patients with Graves' disease (GD; n = 15), non-toxic nodular goiter (NTNG; n = 10) and toxic nodular goiter (TNG; n = 10). GPR39 and GHSR in thyroid tissues were detected by immunohistochemistry and Western blot, revealing higher expression of both proteins in GD patients (+++; ++) in comparison with NTNG (+; +) and TNG (++; +) patients. GPR39 was present in thyroid autoimmune disease, NTNG and TNG at band p51 (kDa). The ghrelin receptor was identified in all study groups at p70. mRNA expression for preproghrelin was found in thyroid tissues from patients with immune and non-immune thyroid diseases. We conclude that the expression of the ghrelin receptor family in thyroid tissues may suggest a role of gastric peptides in thyroid functions. mRNA of preproghrelin expression is a proof of ghrelin gene-derived peptide presence in thyroid tissues.

[Cytofluorometric analysis of chosen markers of apoptosis CD95/CD95L (Fas/FasL) in thyroid tissues from young patients with Graves' disease and Hashimoto's thyroiditis]. / Cytofluorymetryczna analiza wybranych markerów apoptozy Fas/FasL (CD95/CD95L) w tkance gruczolu tarczowego u mlodocianych pacjentów z choroba Gravesa-Basedowa oraz zapaleniem tarczycy typu Hashimoto.

BACKGROUND: Apoptosis, one of the forms of programmed cell death, is a physiologic process of cell death that is central to normal development and occurs in response to a variety of physiologic and pathophysiologic stimuli. In the thyroid, abnormal apoptotic activity may be involved in a variety of diseases such as Hashimoto thyroiditis and Graves disease. The aim of this study was to estimate the expression of chosen apoptotic molecules CD95 (Fas) and CD95L (FasL) on the surface of thyroid follicular cells in application of mouse monoclonal antibodies #64 which recognized B antigen regions of thyroid peroxidase (TPO) and infiltrating inflammatory cells. MATERIAL AND METHODS: The investigation was performed on thyroid cells isolated from surgically treated thyroid tissues of 15 patients with Graves' disease (GD), 15 patients with a nontoxic multinodular goiter (NTMG) and 15 aspirates obtained by FNAB from patients with Hashimoto thyroiditis (HT). The thyrocytes were identified by an indirect method: in the first stage we added mouse monoclonal autoantibodies specific for TPO (mAb #64) regions and in the second stage we conjugated this complex with rabbit anti-mouse antibodies IgG (Fab')2 with FITC. In the next step the cellular suspension was completed with suitably well-chosen two-colour monoclonal antibodies marked (PE or PerCP) (Becton Dickinson) directed against suitable apoptotic (Fas/FasL) molecules. All investigations were performed by flow cytometry using Coulter EPICS XL apparatus. RESULTS: The percentages of thyroid cells were estimated with expression of region B antigenic TPO in reference to individual apoptotic molecules. The analysis of Fas and FasL expression in thyroid tissues revealed significantly increased percentage of intrathyroidal T cells with CD95+ (p<0.005, p<0.001), CD95L+ (p<0.02, p<0.01) and both CD95/CD95L (ns, p<0.05) expression in comparison to percentages of T cells in patients with HT and NTMG. In addition, on the surface of thyroid follicular cells in patients with GD (p<0.01, p<0.01) and NTMG (p<0.001, p<0.004) we observed a lower percentage of thyrocytes with CD95 and CD95L molecules than in cases with HT. The expression of both apoptotic molecules on thyroid cells was higher (18%) in patients with HT in comparison to the percentages of positive cells in patients with GD (p<0.02, p<0.002) and NTMG, 8% and 1%, respectively. CONCLUSIONS: We conclude that alterations in the expression of death receptors and their ligands on the surface of thyroid follicular cells may play a role in the regulation of apoptosis in thyroid autoimmune disorders.