Espressione del complesso della polarità cellulare PAR nei carcinomi tiroidei differenziati e indifferenziati: correlazione con parametri clinico-patologici

Establishment and maintenance of the apical-basal cell polarity, required for proper replication, migration, specialized functions and tissue morphogenesis, relies on three evolutionary conserved complexes: PAR, CRUMBS and SCRIBBLE. Loss Of cell Polarity/Cohesiveness (LOP/C) is implicated in cancer progression, and members of the polarity complex have been described as either oncogenes or oncosuppressors. However, no information on their role in thyroid cancer (TC) progression is available. In this study, we evaluated the gene expression of the PAR complex members aPKCι, PARD3α/β and PARD6α/β/γ in 95 papillary TC (PTC), compared to their normal matched tissues, and in 12 anaplastic TC (ATC). The mRNA and protein levels of investigated genes were altered in the majority of PTC and ATC tissues. In PTC, univariate analysis showed that reduced expression of aPKCι, PARD3β and PARD6γ mRNAs is associated with increased tumor size, and the reduced expression of PARD3β mRNA is associated also with recurrences. Multivariate analysis demonstrated that the presence of lymph node metastasis at diagnosis and the reduced expression of PARD3β are independent risk factors for recurrences, with hazard ratio, respectively, of 8.21 (p=0.006) and 3.04 (p=0.029). The latter result was confirmed by Kaplan-Meier analysis, which evidenced the association between decreased PARD3β mRNA levels and shorter disease-free interval. In conclusion, we demonstrated that the expression of PAR complex components is deregulated in the majority of PTC and ATC tissues. Moreover, a prognostic value for the PARD3β gene in PTCs is suggested

Aurora Kinases: New Molecular Targets for the Therapy of Aggressive Thyroid Cancers

Epithelial thyroid carcinomas (TC) account for more than 90% of all endocrine malignancies and represent one of the most frequent cancers in women. They include the well-differentiated TC (DTC), comprising the papillary (PTC) and follicular (FTC) histotypes, the poorly differentiated (PDTC), and the undifferentiated or anaplastic TC (ATC). Both PDTC and ATC are aggressive human neoplasms with a dire prognosis due to the absence of effective therapies, which makes mandatory the identification of novel therapeutic strategies. Intrinsic chromosomal instability (CIN, an increased rate of gain or losses of chromosomes during cell division) is a common feature of solid tumors and represents a major driving force in thyroid cancer progression, thought to be responsible for the acquisition by malignant cells of novel functional capabilities. Different mitotic kinases, whose expression or function has been found altered in human cancer tissues, are major drivers of thyroid tumor aneuploidy. Among these are the three members of the Aurora family (Aurora-A, Aurora-B and Aurora-C), serine/threonine kinases that regulate multiple aspects of chromosome segregation and cytokinesis. Over the last few years, several small molecule inhibitors targeting Aurora kinases were developed with promising antitumor effects in preclinical and clinical studies against different human cancers, including TC. Here, we will focus on the Aurora mitotic functions in normal cells; we shall then describe the main implications of their overexpression in the onset of genetic instability and aneuploidy. We will finally describe the consequences of Aurora kinase inhibition on TC cell growth and tumorigenicity

New molecular approaches in the diagnosis and prognosis of thyroid cancer patients

Thyroid nodules are very common in the adult population, but only a minority of them harbor a malignant lesion. Therefore, the first aim in their clinical evaluation is to exclude malignancy. To date, the fine-needle aspiration cytology (FNAC) represents the main diagnostic tool for the evaluation of thyroid nodules and cervical lymph nodes (CLN) suspected of metastatic disease. It has to be mentioned, however, that FNAC on thyroid nodules suffers from a major diagnostic limit represented by cellular atypias of indeterminate significance, which require the histological diagnosis. Also the FNAC performed on CLN may be a challenging diagnostic category as CLN could harbor metastases from a multiplicity of extrathyroidal malignancies or be affected by several non-tumoral diseases. In addition, inadequate cellularity obtained from both thyroid nodules or CLN prevents diagnosis in about 20% of specimens. Total thyroidectomy followed by adjuvant therapy with 131I is the treatment of choice for most patients affected by DTC. Although the prognosis of DTC patients is favorable, about 20% of them face the morbidity of disease recurrence and tumor-related deaths. Thus far, the prognosis of these patients still relies on clinic-pathological variables such as patient’s age, tumor size, histology, lymph node or distant metastasis, which are not accurate in predicting the long-term outcome. As a consequence, the identification of new molecular biomarkers strictly related to the risk of DTC relapse is highly needed. In the present review we’ll attempt to summarize the recent characterization of new molecular markers able to ameliorate the diagnosis and prognosis of thyroid cancer patients

CTLA-4 and PD-1 ligand gene expression in epithelial thyroid cancers

The dysregulation of PD-1 ligands (PD-L1 and PD-L2) and CTLA-4 ligands (CD80 and CD86) represents a tumor strategy to escape the immune surveillance. Here, the expression of PD-L1, PD-L2, CD80 and CD86 was evaluated at mRNA level in 94 patients affected by papillary thyroid carcinoma (PTC) and 11 patients affected by anaplastic thyroid carcinoma (ATC). Variations in the mRNAs in PTC patients were then correlated with clinicopathological features. The expression of all genes was deregulated in PTC and ATC tissues compared to normal tissues. In particular, the down-regulation of CD80 was observed in above all ATC. In addition, the increased expression of CD80 associated to longer disease-free survival in PTC. Higher expression of PD-L1 associated with the classical histological variant and with the presence of BRAFV600E mutation in PTC. The increased PD-L2 expression correlated with BRAFV600E mutation and lymph node metastasis, while its lower expression correlated with the follicular PTC variant. The latter was also associated with the CD80 down-regulation, which was also related to the absence of lymph node metastasis. In conclusion, we documented the overall dysregulation of PD-1 and CTLA-4 ligands in PTC and ATC tissues and a possible prognostic value for CD80 gene expression in PTC

Thyroid autoantibodies and breast cancer

Dear Editor We read with interest the recent article by Shi and colleagues (2014) reporting a meta-analysis on the relationship between thyroid hormones, thyroid autoantibodies and breast cancer (BC). In the paper, the authors analyzed eight different studies, including 4,189 participants, and concluded that serum levels of free-triiodothyronine, thyroperoxidase and thyroglobulin autoantibodies are higher in patients affected by BC, compared with the control group. These findings are in agreement with the meta-analysis reported by Hardefeldt and colleagues, showing an increased risk of BC in patients with autoimmune thyroid disease, and with a recent article by our group in which the prevalence of BC in 3,921 female patients affected by both benign and malignant thyroid diseases was evaluated (Hardefeldt et al., 2012; Prinzi et al., 2014). In the latter, we showed that the prevalence of BC in patients affected by thyroid disease, as a whole, was significantly higher, compared to the general population (OR 3.3). Moreover, the age-matched analysis showed that the risk of BC was higher in younger patients (0–44 yr, OR 15.2), to decline with the increasing age. In the same study, when patients were dichotomized based on the presence or the absence of thyroglobulin and/or thyroperoxidase autoantibodies, both groups showed a higher risk of BC, compared to the general female population. When the two groups were compared to each other, however, the risk of BC was significantly lower in autoantibody positive patients. Thus, as clearly stated in our article, among patients affected by thyroid diseases, the presence of thyroid autoantibodies may have a protective role against BC (Prinzi et al., 2014). As a consequence, the sentence reported by Shi and colleagues in the Discussion section of their article stating that their findings are in disagreement with our data is not correct and should be, if at all possible, amended

Alterata espressione dei geni coinvolti nel processo di sumoilazione nel carcinoma papillare della tiroide.

La modificazione post-traslazionale di proteine da parte delle proteine SUMO (small ubiquitin-related modifiers) consiste nella loro coniugazione covalente e reversibile a specifici residui di lisina di proteine bersaglio, con conseguente alterazione della localizzazione subcellulare e dell’attività di queste ultime. La SUMOilazione è implicata in svariati processi biologici tra cui la proliferazione cellulare, l’apoptosi, la riparazione del DNA e la sopravvivenza cellulare. Studi recenti hanno mostrato che la deregolazione del sistema SUMO contribuisce alla trasformazione tumorale modificando l’attività di molteplici oncoproteine e oncosoppressori. Ad oggi, si conosce molto poco riguardo al ruolo della SUMOilazione nel carcinoma papillare della tiroide (PTC). Pertanto, la presente ricerca è stata volta a caratterizzare l’espressione a livello di mRNA di un pannello di geni coinvolti nel processo di SUMOilazione in questo tumore. In particolare, è stata analizzata l’espressione dei geni: a) codificanti per gli enzimi SENP, cistein-proteasi in grado di rimuovere le proteine SUMO dalle proteine bersaglio; b) codificanti per SAE1 e UBA2 che formano un eterodimero attivante le proteine SUMO; c) codificante l’enzima coniugante Ubc9; d) codificanti le E3 ligasi PIAS1-4, RanBP2, NSMCE2, CBX4 e ZMIZ1-2. A tal fine, 20 campioni di tessuto normale e tumorale prelevati da pazienti affetti da PTC sono stati sottoposti a RT-PCR quantitativa, e l’analisi dei dati è stata eseguita con il software Lightcycler Relative Quantification. I risultati ottenuti hanno evidenziato una diminuzione significativa dei livelli di mRNA dei geni SAE1, ZMIZ1, PIAS1, PIAS2 e SENP8. Benché la rilevanza di tali alterazioni nel contesto degli eventi di SUMOilazione debba essere ancora determinata, le nostre osservazioni evidenziano una deregolazione del processo di SUMOilazione nei PTC, che merita ulteriori approfondimenti al fine di accertarne l’eventuale ruolo patogenetico

Ability of selective small molecule inhibitors of Aurora-A and Aurora-B in inhibiting tumorigenicity of anaplastic thyroid carcinoma-derived cell lines.

Aurora kinases are a family of serine/threonine kinases which play an essential role in cell division. Their aberrant expression and/or function bring about severe mitotic abnormalities resulting in either cell death or aneuploidy. Aurora kinases are often found overexpressed in a variety of malignancies among which thyroid cancers, and particularly in the most aggressive form, the anaplastic thyroid carcinoma (ATC). In previous studies we demonstrated the in vitro efficacy of small molecule inhibitors of Aurora kinases in restraining cell growth and survival of different ATC derived cell lines. In the present preclinical study we sought to establish which of the Auroras is the best drug target for ATC therapy. To this end, the effects of two selective inhibitors of Aurora-A (MLN8237/Alisertib) and Aurora-B (AZD1152/Barasertib) have been analyzed on a panel of human ATC derived cell lines (CAL-62, BHT-101, 8305C, 8505C). Both inhibitors reduced proliferation of the different cancer cells in a time- and dose-dependent manner, with IC50 ranges of 17.5-86 nM for MLN8237 and of 59-380 nM for AZD1152. Western blot experiments demonstrated that concentrations of inhibitors exerting maximal anti-proliferative effects were still selective for Aurora-A or -B. Moreover, as evidenced by immunofluorescence and time-lapse experiments, each inhibitor induced a distinct cellular phenotype depending on the kinase targeted. Polyploidy increased significantly in all the cell lines treated with AZD1152 and in 2 out of 4 lines treated with MLN8237, while apoptosis was induced by both treatments in all cells. Both drugs were also capable to block anchorage-independent ATC cell growth. In conclusion, our results indicate that selective inhibitors of Aurora-A or Aurora-B display similar efficacy in inhibiting tumorigenicity of ATC-derived cell lines and they might represent new therapeutic options for ATC treatment

Emerging molecular markers for the prognosis of differentiated thyroid cancer patients

Epithelial thyroid cancers are represented by the differentiated papillary and follicular thyroid carcinomas which, following dedifferentiation, are thought to give rise to the highly aggressive and incurable anaplastic thyroid carcinomas. Although derived from the same cell type, the different thyroid tumors show specific histological features, biological behavior and degree of differentiation as a consequence of different genetic alterations. Over the last few years, our knowledge regarding the molecular alterations underlying thyroid cell malignant transformation and cancer progression has considerably increased; however, the prognosis of differentiated thyroid cancer patients still relies on high-risk clinic-pathological variables. In particular, the actual staging systems provides only a rough prediction for cancer mortality and risk of recurrences, including in each risk group patients with highly different tumor-specific progression, disease-free interval and survival time. In order to improve DTC patient's risk stratification, both the European and the American Thyroid Associations proposed practical guidelines to integrate the actual staging systems with additional clinical features such as the tumor histological variant, the results of post-ablative whole body scan and the serum thyroglobulin levels. Despite that, patients within the same risk group still show a very heterogeneous behavior in terms of disease-free interval. As a consequence, the identification of new prognostic molecular biomarkers able to testify tumor aggressiveness is highly required. Here we'll review recently characterized new molecular markers potentially able to ameliorate the prognosis in DTC patients. © 2014 Surgical Associates Ltd

Preclinical testing of selective Aurora kinase inhibitors on a medullary thyroid carcinoma-derived cell line

Purpose: Deregulated expression of the Aurora kinases (Aurora-A, -B and -C) is thought to be involved in cell malignant transformation and genomic instability in several cancer types. Over the last decade, a number of small molecule inhibitors of Aurora kinases have been developed, which have proved to efficiently restrain malignant cell growth and tumorigenicity. Regarding medullary thyroid carcinoma (MTC), we previously showed the efficacy of a pan-Aurora kinase inhibitor (MK-0457) in impairing growth and survival of the MTC-derived cell line TT. In the present study, we sought to establish if one of the Aurora kinases might represent a preferential inhibitor target for MTC. Methods: The effects of selective inhibitors of Aurora-A (MLN8237) and Aurora-B (AZD1152) were analyzed on TT cell proliferation, apoptosis, cell cycle and ploidy. Results: The two inhibitors reduced TT cell proliferation in a time- and dose-dependent manner, with IC50 19.0±2.4 nM for MLN8237 and 401.6±44.1 nM for AZD1152. Immunofluorescence experiments confirmed that AZD1152 inhibited phosphorylation of histone H3(Ser10) by Aurora-B, while did not affect Aurora-A autophosphorylation. MLN8237 inhibited Aurora-A autophosphorylation as expected, but at concentrations required to achieve the maximum antiproliferative effects it also abolished H3(Ser10) phosphorylation. Cytofluorimetry experiments showed that both inhibitors induced accumulation of cells in G2/M phase and increased the subG0/G1 fraction and polyploidy. Finally, both inhibitors triggered apoptosis. Conclusions: We demonstrated that inhibition of either Aurora-A or Aurora-B has anti-proliferative effects on TT cells, and thus it would be worthwhile to further investigate the therapeutical potential of Aurora kinase inhibitors in MTC treatment

Consumption of iodized salt may not represent a reliable indicator of iodine adequacy. Evidence from a cross-sectional study on schoolchildren living in an urban area of central Italy

Objective: It is established that iodine prophylaxis prevents endemic goiter. Here, we first reported the amount of iodized salt sold by the retailers of Cassino city of central Italy. We then evaluated the effects of iodine prophylaxis program started in 2005 on urinary iodine concentration (UIC) and thyroid volume (TV), and their correlation with anthropometric parameters in a schoolchild population. Research Methods & Procedures: The study included 234 schoolchildren (119 girls and 115 boys) aged 13-14 yr. Each student provided a morning urine sample for UIC determination, and TV was evaluated by ultrasonography. Body weight and height were also measured. Each participant filled out a questionnaire reporting the presence of thyroid disease and the consumption of iodized salt and iodine-rich food. Results: The percentage of iodized salt sold by local markets was 42.4%. Median UIC in schoolchildren was 133.9 g/L (range 33.2-819.5 g/L), with 71 subjects having mild (range 50.1-99.9 g/L) and 10 moderate (range 33.2-48.8 g/L) iodine deficiency. Eleven subjects showed excessive iodine intake (range 300.4-819.5 g/L). Median UIC was higher in children using iodized salt or consuming milk. Goiter prevalence was 3.8%. A positive correlation between TV and body weight, height and surface was observed. Conclusions: The data reported may suggest the presence of an adequate iodine intake in the population of Cassino despite the low percentage of iodized salt sold by local retailers. This indicates that silent iodine prophylaxis through the consumption of iodine-rich or iodine-enriched food is of importance in the prevention of iodine deficiency disorders