1,721,035 research outputs found
Nuovo approccio nel trattamento del carcinoma midollare tiroideo
Get PDFIl carcinoma midollare della tiroide (MTC) pur costituendo solamente il 5-10% di tutti i tumori tiroidei ha una prognosi infausta e risulta resistente ai trattamenti convenzionali. La mutazione di RET costituisce il marcatore molecolare a valenza prognostica più importante. Scopo dello studio è stato testare tre composti ZSTK474 e XL184 ed EF24 in linee cellulari di MTC stabilizzate e primarie attraverso varie metodiche tra cui saggi di vitalità, analisi delle vie di segnale, valutazione della modulazione del ciclo cellulare, apoptosi, motilità e dosaggio della calcitonina. Abbiamo studiato l'effetto di questi composti, singolarmente e in combinazione, in due linee cellulari umane stabilizzate di MTC, TT e MZ-CRC-1, mutate entrambe per RET, e in sei colture primarie di MTC. I bassi valori di IC50 hanno dimostrato l'efficacia dei farmaci, mentre l'indice di combinazione ha rivelato un importante effetto sinergico delle combinazioni di XL184 + ZSTK474 e XL184 + EF24. Inoltre abbiamo osservato, utilizzando i composti singolarmente e in combinazione, variazioni del ciclo cellulare e induzione di apoptosi o di necrosi. Sia XL184 che EF24, usati singolarmente o in combinazione, erano efficaci nel ridurre la secrezione di calcitonina. Mentre mediante l’utilizzo del Western blot e dell’In-Cell Western abbiamo potuto vedere l’efficacia dei composti nell’inibire le principali vie di segnale, MAPK e PI3K/Akt. Per di più in questo studio è stato testato per la prima volta EF24 negli MTC, dimostrando che già utilizzandolo singolarmente è efficace nell'inibire la vitalità cellulare. Abbiamo inoltre testato anche le combinazioni XL184 + ZSTK474 e XL184 + EF24, scoprendo che agiscono in modo sinergico, indipendentemente dallo stato mutazionale di RET. Questi risultati confermano e supportano l’idea che l’inibizione contemporanea di molteplici vie abbia un maggiore impatto clinico
L’elastosonografia come sostituto dell’esame citologico nei nodi soffici
No full textContesto: l’elastosonografia è una metodica sempre più utilizzata nello studio ecografico dei nodi tiroidei. In un nostro precedente studio abbiamo dimostrato la maggior affidabilità dello Strain Index (SI), ovvero l’elasticità misurata del nodo, rispetto allo Strain Ratio (SR), cioè il rapporto dell’elasticità del tessuto tiroideo e di quella del nodo, e alla scala colorimetrica di Itoh, sia per quanto riguarda la riproducibilità intra- e inter-operatore, sia per l’accuratezza.
Scopo dello studio: si ipotizzava che, per l’elevata sensibilità dimostrata, nei nodi soffici lo SI potesse essere un’alternativa alla citologia, riservando quest’ultima ai soli nodi ipoelastici. Questo lavoro si propone di dimostrare tale ipotesi.
Materiali e Metodi: abbiamo valutato 166 nodi tiroidei, sottoposti consecutivamente a FNAC presso l’UO di Endocrinologia di Padova nel periodo giugno 2012-marzo 2013. confrontando il dato elastografico con quello citologico. Solo per i 12 nodi risultati TIR3 alla citologia, abbiamo tenuto conto dell’esito dell’esame istologico per definirne malignità o benignità. Di ogni nodo abbiamo valutato lo SI (media di due misurazioni) e i fattori di sospetto ecografico classici (ecogenicità, margini, microcalcificazioni).
Risultati: il miglior cut-off per definire soffice un nodulo è risultato SI≥0.15, con sensibilità del 93% e specificità del 71%. Utilizzando tale cut-off, solo 2 nodi sospetti allo
FNAC sono risultati “falsi negativi” all’elastografia: un carcinoma follicolare, che allo FNAC era risultato TIR3, e un TIR4 che in realtà si è rilevato all’intervento un falso positivo della citologia. La sensibilità dei criteri ecografici classici era inferiore (73%), a fronte di una maggiore specificità (89%), con 8 falsi negativi rispetto allo FNAC.
Unendo i criteri ecografici con lo SI non si aggiungeva nulla alla sensibilità rispetto al solo SI. Conclusioni: lo SI si conferma il più importante criterio nella diagnostica ecografica dei nodi tiroidei, permettendo di predire con notevole precisione l’esito negativo di un esame citologico nei noduli soffici (e istologico nei TIR3). Ciò consente di ridurre drasticamente il numero di nodi da sottoporre a FNAC. Tale metodica risulta quindi vantaggiosa per il paziente, che evita un’indagine invasiva, e cost-effective (con risparmio di tempo e risorse)
The combination of RAF265, SB590885, ZSTK474 on thyroid cancer cell lines deeply impact on proliferation and MAPK and PI3K/Akt signaling pathways.
No full textPapillary thyroid cancer (PTC) is the most frequent thyroid cancer entity, accounting for 88 % of cases. It may metastasize and loose iodine uptake capability, preventing any radioiodine or surgical treatment. The main gene altered in PTC is BRAF, which is found altered in over 50 % of cases. Moreover MAPK and PI3K/Akt pathways are greatly implicated in PTC development. Many target therapies for PTC are currently under investigation, unfortunately without the expected results. Aim of this study was to characterized the preclinical effectiveness of novel promising drugs, RAF265, SB590885 and ZSTK474 in 3 thyroid cancer cell lines (BCPAP, K1, 8505C). RAF265 and SB590885 target differentially BRAF, while ZSTK474 acts on PI3K. IC50 demonstrated high drug activities ranging from 0.1 to 6.2 μM, depending on drugs and cell type, while combination index revealed an interesting synergistic effect of combination regimen (RAF265 + ZSTK474 and SB590885 + ZSTK474) in almost all cell lines. Moreover this synergistic effect was particularly evident by Western blot, whereas dual MAPK and PI3K/Akt inhibition was detected. In addition, treating cells with SB590885 induced marked morphological changes, leading to massive vacuolization. This suggests an activation of apoptotic process, as underlined by Annexin V flow cytometry analysis. Also cell cycle was altered in treated cells, without evidence of a common pattern, but rather with a more specific effect relying on single drug or combination regimen used. Since beneficial effects of in vitro combination regimen (RAF265 + ZSTK474 and SB590885 + ZSTK474), it is recommended additional investigation. These data suggest the potential use of combination regimen in in vivo experiment or afterwards in human PTC
A Novel Thyroid Hormone Receptor Beta Mutation (G357R) in a Family with Resistance to Thyroid Hormone Beta: Extending the Borders of the "Hot" Region in the THRB Gene
No full textResistance to thyroid hormone beta (RTHβ) is a syndrome characterized by high serum levels of thyroid hormone and unsuppressed serum thyrotropin concentrations. RTHβ is caused by mutations in the thyroid hormone receptor beta (THRB) gene, which are mostly clustered in three "hot" regions along the gene. Here, a report is given on a family with RTHβ caused by a novel mutation in the THRB gene (c.1069 G>C, p.G357R) occurring outside the historically known "hot" regions
RET codon 609 mutations: a contribution for better clinical managing
No full textMedullary thyroid carcinoma currently accounts for 5-8% of all thyroid cancers. The clinical course of this disease varies from extremely indolent tumors that can go unchanged for years to an extremely aggressive variant that is associated with a high mortality rate. As many as 75% of all medullary thyroid carcinomas are sporadic, with an average age at presentation reported as 60 years, and the remaining 25% are hereditary with an earlier age of presentation, ranging from 20 to 40 years. Germline RET proto-oncogene mutations are the genetic causes of multiple endocrine neoplasia type 2 and a strong genotype-phenotype correlation exists, particularly between a specific RET codon mutation and the (a) age-related onset and (b) thyroid tumor progression, from C-cell hyperplasia to medullary thyroid carcinoma and, ultimately, to nodal metastases. RET mutations predispose an individual to the development of medullary thyroid carcinomas and can also influence the individual response to RET protein receptor-targeted therapies. RET codon 609point mutations are rare genetic events belonging to the intermediate risk category for the onset of medullary thyroid carcinoma. A large genealogy resulting in a less aggressive form of medullary thyroid carcinoma is associated with the high penetrance of pheochromocytoma and has been reported in the literature. In this short review article, we comment on our previous report of a large multiple endocrine neoplasia type 2A kindred with the same Cys609Ser germline RET mutation in which, conversely, the syndrome was characterized by a slightly aggressive, highly penetrant form of medullary thyroid carcinoma that was associated with low penetrance of pheochromocytoma and primary hyperparathyroidism
Calcium/Calmodulin-Dependent Protein Kinase II and Its Endogenous Inhibitor α in Medullary Thyroid Cancer.
No full textPurpose: Calcium/calmodulin-dependent kinase II (CaMKII) is involved in the regulation of cell proliferation. Its endogenous inhibitor (hCaKIINa) is expressed in some cell types. We determined the role of CaMKII in RET-stimulated proliferation and hCaMKIINa in medullary thyroid carcinoma (MTC). Experimental Design: We analyzed the role of RET mutants on CaMKII activation in NIH3T3 and in MTC cell lines, and determined the effect of CaMKII inhibition on RET/ERK pathway and cell proliferation. Then the expression of hCaKIINa mRNA was determined by real-time PCR in primary MTC and it was correlated with some clinicopathologic parameters. Results: RETC634Y and RETM918T mutants expressed in NIH3T3 cells induced CaMKII activation. CaMKII was activated in unstimulated MTC cells carrying the same RET mutants and it was inhibited by RET inhibition. Inhibition of CaMKII in these cells induced a reduction of Raf-1, MEK, and ERK phosphorylation, cyclin D expression, and cell proliferation. hCaKIINa mRNA expression in primary MTC was very variable and did not correlate with gender and age at diagnosis. Serum calcitonin, (R2 1/4 0.032; P 1/4 0.017), tumor volume (P 1/4 0.0079), lymph node metastasis (P 1/4 0.033), and staging (P 1/4 0.0652) were negatively correlated with the hCaKIINa mRNA expression. Conclusions: CaMKII is activated by RET mutants and is activated at baseline in MTC cells where it mediates the oncogenic pathway leading to cell proliferation. The mRNA expression of its endogenous inhibitor hCaKIINa inversely correlates with the severity of MTC. CaMKII might represent a new target for MTCtherapy and hCaKIINais a marker of disease extension
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy: report of seven additional sicilian patients and overview of the overall series from sicily.
No full textBackground: Autoimmune polyendocrinopathy-candidiasis- ectodermal dystrophy (APECED) is a rare recessive inherited disease caused by the mutation of the AIRE gene on chromosome 21. To date, 8 Sicilian patients have been described and the R203X AIRE mutation was found to be the most common in this region. Aims: (1) To describe 7 additional Sicilian APECED patients and to review all 15 Sicilian APECED patients who have been investigated by our group in the last years, and (2) to report a novel AIRE gene mutation. Results: Among the 3 cardinal features of APECED, hypoparathyroidism has been already detected in all 15 patients, whereas Addison's disease and chronic mucocutaneous candidiasis have so far been found in 10/15 and 12/15 cases, respectively. In 2 consanguineous cases, AIRE gene analysis revealed a novel mutation, named IVS13+2T, in homozygosis. R203X was the most common mutation in this region (30% of alleles and 46.6% of patients), followed by R257X (20% of alleles and 40% of patients). Conclusions: Sicilian APECED patients are confirmed to have some peculiar characteristics from a clinical and genetic point of view. No correlations between genotype and phenotype were identified
Early, Prophylactic Thyroidectomy in Hereditary Medullary Thyroid Carcinoma: A 26-year Monoinstitutional Experience.
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