Terapias moleculares direcionadas em câncer de tireoide

Thyroid cancer incidence has significantly increased in the last three decades and many patients seek medical attention for its treatment every year. Among follicular cell-derived tumors, the majority are differentiated thyroid carcinomas (DTC), whose prognosis is very good with only 15% of the cases presenting disease persistence or recurrence after initial treatment. Medullary thyroid carcinoma has a worse prognosis, especially in patients with diffused cancers at the time of initial surgery. Traditional treatment options for persistent or recurrent disease include additional surgery, radioiodine treatment and TSH-suppression in DTC patients; external beam radiotherapy, and cytotoxic chemotherapy, often have low efficacy and many patients with advanced disease ultimately die. In the last two decades many of the molecular events involved in cancer formation have been uncovered. This knowledge has prompted the development of novel therapeutic strategies mainly based on the inhibition of key molecular mediators of the tumorigenic process. In particular the class of small-molecule tyrosine kinase inhibitors was enriched by many compounds that have reached clinical trials and in some cases have had approval for clinical use in specific cancers. Many of these compounds entered clinical trials also for locally advanced or metastatic thyroid carcinomas showing very promising results

Targeting the thyroid gland with thyroid-stimulating hormone (TSH)-nanoliposomes

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Sunitinib Exerts Only Limited Effects on the Proliferation and Differentiation of Anaplastic Thyroid Cancer Cells

Background: Novel molecularly targeted drugs are undergoing preclinical and clinical testing to assess their efficacy against refractory thyroid carcinomas. The multikinase inhibitor Sunitinib has been shown to inhibit the kinase activity of the RET oncogene and reduce proliferation in differentiated thyroid cancer cells harboring the RET/PTC rearrangement. In this study, we evaluated its effects in human cell lines derived from differentiated (TPC-1) and anaplastic (8505C, CAL-62, and C643) thyroid cancers. Methods: The cells exposed to various concentrations of Sunitinib were examined for: (1) cell viability and presence of apoptosis, analyzed by cell counts, MTT assay, trypan blue exclusion assay, western blotting, and immunofluorescence; (2) expression of cyclin D1 and phosphorylated and nonphosphorylated extracellular signal-regulated kinase (ERK) and Akt proteins, analyzed by western blotting; and (3) transcription of genes encoding thyrocyte differentiation markers (thyroid-stimulating hormone receptor, sodium/iodide symporter, thyroglobulin, and thyroperoxidase) and proangiogenic factors (vascular endothelial growth factor A, platelet-derived growth factors A and B), measured by quantitative reverse transcriptase-polymerase chain reaction. Results: Exposure to nanomolar concentrations of Sunitinib significantly reduced cell viability in only TPC-1 cells, and this effect was paralleled by reduction of cyclin D1 levels. Western blotting revealed reduced phosphorylation of ERK and Akt after 3 and 6 hours of drug exposure. In contrast, the growth of 8505C, CAL-62, and C-643 cells was significantly reduced only by micromolar concentrations of Sunitinib, mainly due to induced necrotic rather than apoptotic death. In these cells, Sunitinib exerted a few significant effects on the transcription of angiogenic factors or thyrocyte differentiation markers. Conclusions: Sunitinib has little or no effect on the growth or differentiation of anaplastic thyroid cancer cells, thus suggesting that it is unlikely to be effective in the treatment of anaplastic thyroid cancer

Signal Transducer and Activator of Transcription 1 Plays a Pivotal Role in RET/PTC3 Oncogene-induced Expression of Indoleamine 2,3-Dioxygenase 1

Indoleamine 2,3-dioxygenase 1 (IDO1) is a single chain oxidoreductase that catalyzes tryptophan degradation to kynurenine. In cancer, it exerts an immunosuppressive function as part of an acquired mechanism of immune escape. Recently, we demonstrated that IDO1 expression is significantly higher in all thyroid cancer histotypes compared with normal thyroid and that its expression levels correlate with T regulatory (Treg) lymphocyte densities in the tumor microenvironment. BRAF(V600E)- and RET/PTC3-expressing PcCL3 cells were used as cellular models for the evaluation of IDO1 expression in thyroid carcinoma cells and for the study of involved signal transduction pathways. BRAF(V600E)-expressing PcCL3 cells did not show IDO1 expression. Conversely, RET/PTC3-expressing cells were characterized by a high IDO1 expression. Moreover, we found that, the STAT1-IRF1 pathway was instrumental for IDO1 expression in RET/PTC3 expressing cells. In detail, RET/PTC3 induced STAT1 overexpression and phosphorylation at Ser-727 and Tyr-701. STAT1 transcriptional regulation appeared to require activation of the canonical NF-κB pathway. Conversely, activation of the MAPK and PI3K-AKT pathways primarily regulated Ser-727 phosphorylation, whereas a physical interaction between RET/PTC3 and STAT1, followed by a direct tyrosine phosphorylation event, was necessary for STAT1 Tyr-701 phosphorylation. These data provide the first evidence of a direct link between IDO1 expression and the oncogenic activation of RET in thyroid carcinoma and describe the involved signal transduction pathways. Moreover, they suggest possible novel molecular targets for the abrogation of tumor microenvironment immunosuppression. The detection of those targets is becoming increasingly important to yield the full function of novel immune checkpoint inhibitors

Serenoa repens + selenium + lycopene vs tadalafil 5 mg for the treatment of lower urinary tract symptoms secondary to benign prostatic obstruction: a Phase IV, non-inferiority, open-label, clinical study (SPRITE study)

Objective: To compare in a randomised, open-label, non-inferiority clinical study, the efficacy and tolerability of Serenoa repens (SeR) + selenium (Se) + lycopene (Ly) (SeR-Se-Ly) therapy vs tadalafil 5 mg in men with lower urinary tract symptoms (LUTS). Patients and methods: From May 2015 to January 2017, 427 patients were enrolled in 21 different centres (International Standard Randomised Controlled Trial Number Register [ISRCTN] 73316039). Inclusion criteria included: age between 50 and 80 years, International Prostate Symptom Score (IPSS) 6512, maximum urinary flow rate (Q max ) 64 15 mL/s, and post-void residual (PVR) <100 mL. Patients were randomised into two groups in a 2:1 ratio: Group A (SeR-Se-Ly, 1 tablet daily for 6 months) and Group B (tadalafil 5 mg, 1 tablet daily for 6 months). The primary endpoint of the study was the non-inferior variation in the IPSS and Q max in Group A vs Group B after 6 months of treatment. Results: In all, 404 patients completed the full protocol. When comparing both therapies, Group A was statistically not inferior to Group B considering the median change in IPSS ( 123.0 vs 123.0; P < 0.01), IPSS quality of life ( 122.0 vs 122.0; P < 0.05), and Q max (2.0 vs 2.0 mL/s; P < 0.01). We found statistically significant differences in the increase of at least 3 points in Q max (38.2% vs 28.1%; P = 0.04) and of at least 30% of Q max (39.2% vs 27.3%; P < 0.01) in Group A compared to Group B. The percentage of patients with an increase of at least 3 points in the IPSS and a decrease of at least 25% of the IPSS was not statistically different between the two groups. For adverse events, four patients in Group A (1.44%) and 10 in Group B (7.81%) (P < 0.05) reported side-effects. Conclusion: We have shown that treatment with SeR-Se-Ly was not inferior to tadalafil 5 mg for improving IPSS and Q max in men with LUTS