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Desenvolvido pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia (SBEM), o Guia Prático em Doenças da Tireoide está integrado ao rol de materiais de divulgação científica e educação médica lançados pela instituição nos últimos anos. Em 28 capítulos elaborados por professores, pesquisadores e endocrinologistas com reconhecimento mundial e larga experiência clínica, o guia contempla tópicos que se estendem da fisiologia tireoidiana à abordagem diagnóstica e terapêutica dos pacientes com as mais diversas doenças da tireoide. A confiabilidade dos dados compilados e o sólido conhecimento de seus colaboradores condicionam este livro como auxílio essencial para consulta durante o atendimento dos pacientes em consultórios, ambulatórios ou enfermarias, além de oportunidade única de atualização a estudantes, médicos residentes e profissionais com particular interesse na Tireoidologia.

Oral cancer squamous cell carcinoma (OCSCC) mainly affects individuals aged between 50 and 70 years who consume tobacco and alcohol. Tobacco smoke contains hundreds of known toxic and carcinogenic molecules, and a few studies have sought to verify the relationship of such trace elements as risk or prognostic factors for head and neck cancer. We obtained 78 samples of tumor tissues from patients with OCSCC, and performed a qualitative elemental characterization using the micro X-Ray Fluorescence technique based on synchrotron radiation. We found the presence of magnesium, phosphorus, sulfur, chlorine, potassium, calcium, chromium, manganese, iron, zinc, cobalt, nickel, copper, arsenic and bromine in OCSCC samples. Magnesium, chlorine, chromium, manganese, nickel, arsenic and bromine are associated with smoking. We observed a significant association between relapse and chlorine and chromium. The presence of chlorine in the samples was an independent protective factor against relapse (OR = 0.105, CI = 0.01–0.63) and for best disease-free survival (HR = 0.194, CI = 0.04–0.87). Reporting for the first time in oral cancer, these results suggest a key relationship between smoking and the presence of certain elements. In addition, chlorine proved to be important in the context of patient prognosis and survival.

Important advances on the role of genetic alterations in thyroid cancer have been achieved in the last two decades. One key reason is linked to the development of technical approaches that allowed for the mimicking of genetic alterations in vitro and in vivo and, more recently, the gene editing methodology. The CRISPR/Cas methodology has emerged as a tangible tool for editing virtually any DNA sequence in the genome. To induce a double-strand break and programmable gene editing, Cas9 endonuclease is guided by a single-guide RNA (sgRNA) that is complementary to the target sequence in DNA. The gene editing per se occurs as the cells repair the broken DNA and may erroneously change the original DNA sequence. In this review, we explore the principles of the CRISPR/Cas system to facilitate an understanding of the mainstream technique and its applications in gene editing. Furthermore, we explored new applications of CRISPR/Cas for gene modulation without changing the DNA sequence and provided a Dry Lab experience for those who are interested in starting “CRISPRing” any given gene. In the last section, we will discuss the progress in the knowledge of thyroid cancer biology fostered by the CRISPR/Cas gene editing tools.

Papillary thyroid carcinoma (PTC) is the most common neoplasm of the endocrine system and has an excellent long-term prognosis, with low rates of distant metastatic disease. Although infrequent, there are cases of deaths directly related to PTC, especially in patients with metastatic disease, and the factors that could be associated with this unfavorable outcome remain a major challenge in clinical practice. Recently, research into genetic factors associated with PTC has gained ground, especially mutations in the TERT promoter and BRAF gene. However, the role of microRNAs remains poorly studied, especially in those patients who have an unfavorable outcome at follow-up. This paper aims to evaluate molecular markers related to the different pathological processes of PTC, as well as the histological characteristics of the neoplasm, and to compare this profile with prognosis and death from the disease using an analysis of patients treated for metastatic disease in a single tertiary cancer center. Evaluation of microRNA expression in paraffin-embedded tumor specimens was carried out by quantitative PCR using the TaqMan® Low Density Array (TLDA) system. Metastatic patients who died from progression of PTC had higher expressions of miR-101-3p, miR-17-5p, and miR-191-5p when compared to patients with stable metastatic disease. These findings are of great importance but should be considered as preliminary because of the small sample.

Purpose Ciliary epithelium (CE) of adult mammalian eyes contains quiescent retinal progenitor/stem cells that generate neurospheres in vitro and differentiate into retinal neurons. This ability doesn't evolve efficiently probably because of regulatory mechanisms, such as microRNAs (miRNAs) that control pluripotent, progenitor, and differentiation genes. Here we investigate the presence of Let-7 miRNAs and its regulator and target, Lin28 and Hmga2, in CE cells from neurospheres, newborns, and adult tissues. Methods Newborn and adult rats CE cells were dissected into pigmented and nonpigmented epithelium (PE and NPE). Newborn PE cells were cultured with growth factors to form neurospheres and we analyzed Let-7, Lin28a, and Hmga2 expression. During the neurospheres formation, we added chemically modified single-stranded oligonucleotides designed to bind and inhibit or mimic endogenous mature Let-7b and Let-7c. After seven days in culture, we analyzed neurospheres size, number and expression of Let-7, Lin28, and Hmga2. Results Let-7 miRNAs were expressed at low rates in newborn CE cells with significant increase in adult tissues, with higher levels on NPE cells, that does not present the stem cells reprogramming ability. The Lin28a and Hmga2 protein and transcripts were more expressed in newborns than adults cells, opposed to Let-7. Neurospheres presented higher Lin28 and Hmga2 expression than newborn and adult, but similar Let-7 than newborns. Let-7b inhibitor upregulated Hmga2 expression, whereas Let-7c mimics upregulated Lin28 and downregulated Hmga2. Conclusions This study shows the dynamic of Lin28-Let-7-Hmga regulatory axis in CE cells. These components may develop different roles during neurospheres formation and postnatal CE cells.

Background: DLK1-DIO3 genomic region comprises one of the largest microRNA (miRNAs) clusters in human genome. In previous studies we showed the downregulation of several miRNAs from the genomic region in papillary thyroid carcinoma (PTC). Due to the large number of miRNAs within this region the individual contribution of these molecules to PTC development and progression remains unclear. Methods: We used different computational resources to clarify the contribution of DLK1-DIO3-derived miRNAs to PTC. Results: Our analysis suggests that 12 miRNAs from this region cooperate to modulate distinct cancer-relevant biological processes, potentially responding for most of the impact of DLK1-DIO3-derived miRNAs to PTC development and progression. The overexpression of miR-485-5p in two PTC cell lines decreased proliferation and migration, confirming the biological relevance of in silico data. Conclusion: Our results shed light on the role of DLK1-DIO3 region, harboring several tumor suppressor miRNAs in thyroid cancer and open perspectives for the functional exploration of these miRNAs as therapeutic targets for PTC.

Vitreous alterations occur from early stages and continue through the normal aging, with gradual lamellae formation and the appearance of liquefied spaces, which eventually leads to complications, such as retinal tear, retinal detachment, and intravitreal hemorrhage. The aim of the present study was to investigate the expression of let-7 miRNA family in the vitreous and retina in newborn (1-3- day-old), young adult (2-month-old), and aging (12-month-old) rats, as well as their role as regulators of vitreous components. MicroRNAs are small, non-coding RNAs that post-transcriptionally regulate gene expression. Our results showed detection of all investigated let-7 isoforms (let-7a, let-7b, let-7c, let-7d, let-7e, let-7f and let-7i) in the retina and vitreous. Although most let-7 members were significantly upregulated in the vitreous during development, only let-7b, let-7c, and let-7e followed this same expression pattern in the retina. Let-7b and -7c increased in aging vitreous as well, and were expressed in vitro by Muller glial cells and their extracellular vesicles. Moreover, let-7 targeted hyaluronan synthase 2 (Has2) mRNA, a synthesizing enzyme of hyaluronan. These observations indicate that let-7 function is important during retina and vitreous development, and that isoforms of let-7 increased with aging, potentially modulating hyaluronan content.

BACKGROUND: It is well known that the dysregulation of microRNAs (miRNAs) has been identified in papillary thyroid carcinoma (PTC), but their roles in the progression and metastasis of PTC remain unclear. MicroRNA-3619-3p (miR-3619-3p) is associated with cancer progression as an oncogene which is predicted to target at the Wnt/β-catenin signaling pathway. Our study aimed to investigate the role of miR-3619-3p on PTC cell migration and invasion, as well as the underlying mechanisms. METHODS: The expression of miR-3619-3p in 36 PTC tissues and corresponding tumor-adjacent tissues, as well as 3 PTC cell lines (BCPAP, K1, TPC-1) and the normal thyroid epithelial cell line (N-thy-ori 3-1) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between miR-3619-3p expression and clinicopathologic status of PTC patients was analyzed. Migration, invasion, and wound healing, were used to evaluate the role of miR-3619-3p in PTC. The activation of β-catenin and the possible molecular pathway were detected by western blotting. RESULTS: The expression of miR-3619-3p in PTC tissues was significantly higher than the corresponding tumor-adjacent tissues (P

Thyroid cancer is the most frequent endocrine malignancy with the majority of cases derived from thyroid follicular cells and caused by sporadic mutations. However, when at least two or more first degree relatives present thyroid cancer, it is classified as familial non-medullary thyroid cancer (FNMTC) that may comprise 3–9% of all thyroid cancer. In this context, 5% of FNMTC are related to hereditary syndromes such as Cowden and Werner Syndromes, displaying specific genetic predisposition factors. On the other hand, the other 95% of cases are classified as non-syndromic FNMTC. Over the last 20 years, several candidate genes emerged in different studies of families worldwide. Nevertheless, the identification of a prevalent polymorphism or germinative mutation has not progressed in FNMTC. In this work, an overview of genetic alteration related to syndromic and non-syndromic FNMTC is presented.

Papillary Thyroid Cancer (PTC) is an endocrine malignancy in which BRAFV600E oncogenic mutation induces the most aggressive phenotype. In this way, considering that lncRNAs are arising as key players in oncogenesis, it is of high interest the identification of BRAFV600E-associated long noncoding RNAs, which can provide possible candidates for secondary mechanisms of BRAF-induced malignancy in PTC. In this study, we identified differentially expressed lncRNAs correlated with BRAFV600E in PTC and, also, extended the cohort of paired normal and PTC samples to more accurately identify differentially expressed lncRNAs between these conditions. Indirectly validated targets of the differentially expressed lncRNAs in PTC compared to matched normal samples demonstrated an involvement in surface receptors responsible for signal transduction and cell adhesion, as well as, regulation of cell death, proliferation and apoptosis. Targets of BRAFV600E-correlated lncRNAs are mainly involved in calcium signaling pathway, ECM-receptor interaction and MAPK pathway. In summary, our study provides candidate lncRNAs that can be either used for future studies related to diagnosis/prognosis or as targets for PTC management.

// Murilo Vieira Geraldo 1, 3 , Helder Imoto Nakaya 2 , Edna Teruko Kimura 1 1 Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil 2 Department of Clinical Analyses and Toxicology, School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil 3 Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Campinas, Brazil Correspondence to: Murilo Vieira Geraldo, email: murilovg@unicamp.br Edna Teruko Kimura, email: etkimura@usp.br Keywords: microRNA, papillary thyroid carcinoma, 14q32 region, microTranscriptome, metastasis Received: September 18, 2016 Accepted: November 26, 2016 Published: December 24, 2016 ABSTRACT Papillary thyroid carcinoma (PTC) is the most prevalent malignant neoplasia of the thyroid gland. A fraction of PTC cases show loss of differentiation and aggressive behavior, with radioiodine therapy resistance and metastasis. Although microRNAs (miRNAs) emerged as promising molecular markers for PTC, their role in the loss of differentiation observed during PTC progression remains to be fully understood. We performed the large-scale analysis of miRNA expression during PTC progression in BRAFT1799A -transgenic animals (Tg-Braf) and thyroid cancer cell lines and identified the marked downregulation of several miRNAs from the region 14q32. Data from The Cancer Genome Atlas (TCGA) confirmed the global downregulation of miRNAs from the 14q32 region in human PTC. The regulatory network potentially suppressed by these miRNAs suggests that key cancer-related biological processes such as cell proliferation, adhesion, migration and angiogenesis. Among the downregulated miRNAs, we observed that miR-654-3p levels decrease with long-term PTC progression in Tg-Braf mice and inversely correlate with EMT. The in vitro restoration of miR-654-3p decreased cell proliferation and migration and induced reprogramming of metastasis-related genes, suggesting a tumor suppressor role for this miRNA. In conclusion, we show global downregulation of 14q32-encoded miRNAs in an in vivo model of PTC progression. The potential circuitry in which these miRNAs are involved suggests that these miRNAs could play a key role in the pathophysiology of PTC and therefore be relevant for the development of new therapeutic strategies.

Thyroid cancer has been rapidly increasing in prevalence among humans in last 2 decades and is the most prevalent endocrine malignancy. Overall, thyroid-cancer patients have good rates of long-term survival, but a small percentage present poor outcome. Thyroid cancer aggressiveness is essentially related with thyroid follicular cell loss of differentiation and metastasis. The discovery of oncogenes that drive thyroid cancer (such as RET, RAS, and BRAF), and are aligned in the MAPK/ERK pathway has led to a new perspective of thyroid oncogenesis. The uncovering of additional oncogene-modulated signaling pathways revealed an intricate and active signaling cross-talk. Among these, microRNAs, which are a class of small, noncoding RNAs, expanded this cross-talk by modulating several components of the oncogenic network – thus establishing a new layer of regulation. In this context, TGFβ signaling plays an important role in cancer as a dual factor: it can exert an antimitogenic effect in normal thyroid follicular cells, and promote epithelial-to-mesenchymal transition, cell migration, and invasion in cancer cells. In this review, we explore how microRNAs influence the loss of thyroid differentiation and the increase in aggressiveness of thyroid cancers by regulating the dual function of TGFβ. This review provides directions for future research to encourage the development of new strategies and molecular approaches that can improve the treatment of aggressive thyroid cancer.

Thyroid cancer is the most common endocrine cancer with predominant prevalence of papillary thyroid cancer (PTC) histotype. MAPK signaling genetic alterations are frequent in PTC, affecting more than 80% of cases. These alterations constitutively activate MAPK signaling cross-regulating different pro-oncogenic pathways. However, additional molecular alterations associated with thyroid cancer are not completely understood. In this extent, the new family of proteins named FAM83 (FAMily with sequence similarity 83) was recently identified as mediator of oncogenic signaling in different types of cancer. Here we report FAM83F as a novel highly expressed protein in PTC. We evaluated FAM83F levels in 106 PTC specimens, 34 goiter, and 41 adjacent non-tumoral human thyroid, and observed FAM83F cytoplasmic overexpression in 71% of PTC (76 of 106) while goiter tissues showed nuclear positivity and normal thyroid showed no staining by immunohistochemistry. Moreover, TSH-induced goiter and BRAF T1799A -induced PTC animal models also showed FAM83F activation. In vitro, we generated a stable thyroid cell line PCCL3 with FAM83F overexpression and observed that FAM83F deregulates thyroid follicular cell biology leading to loss of thyroid differentiation genes such as Sodium-Iodide Symporter (NIS), reactivation of stem cell markers such as LIN28B and SOX2, induction of cell migration and resistance to doxorubicin-induced apoptosis. Moreover, FAM83F activates MAPK signaling through interaction with BRAF and RAF while impairs TGFβ antiproliferative signaling transduction. In this study, we showed FAM83F as a new pro-oncogenic protein overexpressed in thyroid cancer that modulates thyroid follicular cell biology and differentiation through cross-regulation of MAPK and TGFβ signaling.

Type 3 deiodinase (DIO3, D3) is reactivated in human neoplasias. Increased D3 levels in papillary thyroid carcinoma (PTC) have been associated with tumor size and metastatic disease. The objective of this study is to investigate the signaling pathways involved inDIO3upregulation in PTC. Experiments were performed in human PTC cell lines (K1 and TPC-1 cells) or tumor samples.DIO3mRNA and activity were evaluated by real-time PCR and ion-exchange column chromatography respectively. Western blot analysis was used to determine the levels of D3 protein.DIO3gene silencing was performed via siRNA transfection.DIO3mRNA levels and activity were readily detected in K1 (BRAFV600E) and, at lower levels, in TPC-1 (RET/PTC1) cells (PP=0.02 respectively). Similarly,DIO3mRNA levels were higher in PTC samples harboring theBRAFV600Emutation as compared with those with RET/PTC1 rearrangement or negative for these mutations (PBRAFoncogene (PLX4032, 3 μM), MEK (U0126, 10–20 μM) or p38 (SB203580, 10–20 μM) signaling was associated with decreases inDIO3expression in K1 and TPC-1 cells. Additionally, the blockage of the sonic hedgehog (SHH) pathway by cyclopamine (10 μM) resulted in markedly decreases inDIO3mRNA levels. Interestingly, siRNA-mediatedDIO3silencing induced decreases on cyclin D1 expression and partial G1 phase cell cycle arrest, thereby downregulating cell proliferation. In conclusion, sustained activation of the MAPK and SHH pathways modulate the levels ofDIO3expression in PTC. Importantly,DIO3silencing was associated with decreases in cell proliferation, thus suggesting a D3 role in tumor growth and aggressiveness.

Made available in DSpace on 2019-10-04T12:30:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-11-15 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Several studies have demonstrated dysregulated cardiac microRNAs (miRNAs) following cardiac stress and development of cardiac hypertrophy and failure. miRNAs are also differentially expressed in the inflammation that occurs in heart failure and, among these inflammatory-related miRNAs, the miR-155 has been implicated in the regulation of cardiac hypertrophy. Despite these data showing the role of miRNA-155 in cardiomyocyte hypertrophy under a hypertrophic stimulus, it is also important to understand the endogenous regulation of this miRNA without a hypertrophic stimulus to fully appreciate its function in this cell type. The first aim of the present study was to determine whether, without a hypertrophic stimulus, miR-155 overexpression induces H9c2 cardiac cells hypertrophy in vitro. The second objective was to determine whether osteoglycin (Ogn), a key regulator of heart mass in rats, mice, and humans, is post-transcriptionally regulated by miR-155 with a potential role in inducing H9c2 cells hypertrophy. Here, we show that, without a hypertrophic stimulus, miR-155 significantly repressed Ogn protein levels, but induce neither alteration in morphological phenotype nor in the expression of the molecular markers that fully characterize pathological hypertrophy of H9c2 cells. However, most importantly, Ogn silencing in H9c2 cells mimicked the effects of miR-155 overexpression in inducing cellular architecture changes that were characterized by a transition of the cell shape from fusiform to rounded. This is a new role of the post-transcriptional regulation of Ogn by miR-155 in the maintenance of the cardiac cell morphology in physiological and pathological conditions. Sao Paulo State Univ, Inst Biosci Botucatu, Dept Morphol, Botucatu, SP, Brazil Univ Sao Paulo, Inst Biomed Sci, Dept Cell & Dev Biol, Sao Paulo, Brazil Sao Paulo State Univ, Inst Biosci Botucatu, Dept Morphol, Botucatu, SP, Brazil FAPESP: 2012/13961-6 FAPESP: 2014/14340-0

Emerging evidence suggests that unregulated Toll-like receptor (TLR) signaling promotes tumor survival signals, thus favoring tumor progression. Here, the mechanism underlying TLR4 overexpression in papillary thyroid carcinomas (PTC) mainly harboring the BRAFV600E mutation was studied. TLR4 was overexpressed in PTC compared with nonneoplastic thyroid tissue. Moreover, paired clinical specimens of primary PTC and its lymph node metastasis showed a significant upregulation of TLR4 levels in the metastatic tissues. In agreement, conditional BRAFV600E expression in normal rat thyroid cells and mouse thyroid tissue upregulated TLR4 expression levels. Furthermore, functional TLR4 expression was demonstrated in PTC cells by increased NF-κB transcriptional activity in response to the exogenous TLR4-agonist lipopolysaccharide. Of note, The Cancer Genome Atlas data analysis revealed that BRAFV600E-positive tumors with high TLR4 expression were associated with shorter disease-free survival. Transcriptomic data analysis indicated a positive correlation between TLR4 expression levels and MAPK/ERK signaling activation. Consistently, chemical blockade of MAPK/ERK signaling abrogated BRAFV600E-induced TLR4 expression. A detailed study of the TLR4 promoter revealed a critical MAPK/ERK–sensitive Ets-binding site involved in BRAFV600E responsiveness. Subsequent investigation revealed that the Ets-binding factor ETS1 is critical for BRAFV600E-induced MAPK/ERK signaling-dependent TLR4 gene expression. Together, these data indicate that functional TLR4 overexpression in PTCs is a consequence of thyroid tumor-oncogenic driver dysregulation of MAPK/ERK/ETS1 signaling., [Implications]: Considering the participation of aberrant NF-κB signaling activation in the promotion of thyroid tumor growth and the association of high TLR4 expression with more aggressive tumors, this study suggests a prooncogenic potential of TLR4 downstream signaling in thyroid tumorigenesis., This work was supported by fellowships and research grants from Agencia Nacional de Promocion Científica y Tecnologica (PICT-2008-0890 and PICT-2014-2564 to A.M. Masini-Repiso; PICT-2014-0726, PICT-2015-3839 and PICT-2015-3705 to J.P. Nicola), Consejo Nacional de Investigaciones Científicas y Tecnicas, Secretaría de Ciencia y Tecnología of Universidad Nacional de Cordoba, Latin American Thyroid Society and Thyroid Cancer Survivors' Association (to J.P. Nicola), Ministerio de Economía y Competitividad de España - Fondo Europeo de Desarrollo Regional (SAF2016-75531-R to P. Santisteban), and Fundacion Española contra el Cancer (GCB14142311CRES to P. Santisteban).

Background Nc886 is a 102 bp non-coding RNA transcript initially classified as a microRNA precursor (Pre-miR-886), later as a divergent homologue of the vault RNAs (vtRNA 2–1) and more recently as a novel type of RNA (nc886). Although nc886/vtRNA2–1/Pre-miR-886 identity is still controversial, it was shown to be epigenetically controlled, presenting both tumor suppressor and oncogenic function in different cancers. Here, we study for the first time the role of nc886 in prostate cancer. Methods Nc886 promoter methylation status and its correlation with patient clinical parameters or DNMTs levels were evaluated in TCGA and specific GEO prostate tissue datasets. Nc886 level was measured by RT-qPCR to compare normal/neoplastic prostate cells from radical prostatectomies and cell lines, and to assess nc886 response to demethylating agents. The effect of nc886 recovery in cell proliferation (in vitro and in vivo) and invasion (in vitro) was evaluated using lentiviral transduced DU145 and LNCaP cell lines. The association between the expression of nc886 and selected genes was analyzed in the TCGA-PRAD cohort. Results Nc886 promoter methylation increases in tumor vs. normal prostate tissue, as well as in metastatic vs. normal prostate tissue. Additionally, nc886 promoter methylation correlates with prostate cancer clinical staging, including biochemical recurrence, Clinical T-value and Gleason score. Nc886 transcript is downregulated in tumor vs. normal tissue -in agreement with its promoter methylation status- and increases upon demethylating treatment. In functional studies, the overexpression of nc886 in the LNCaP and DU145 cell line leads to a decreased in vitro cell proliferation and invasion, as well as a reduced in vivo cell growth in NUDE-mice tumor xenografts. Finally, nc886 expression associates with the prostate cancer cell cycle progression gene signature in TCGA-PRAD. Conclusions Our data suggest a tumor suppressor role for nc886 in the prostate, whose expression is epigenetically silenced in cancer leading to an increase in cell proliferation and invasion. Nc886 might hold clinical value in prostate cancer due to its association with clinical parameters and with a clinically validated gene signature. Electronic supplementary material The online version of this article (10.1186/s12885-018-4049-7) contains supplementary material, which is available to authorized users.

Background Thyroid cancer is one of the most frequent types of endocrine cancers. In most cases, thyroid cancers are caused by deregulated miRNA expression, especially involving the miR17-92 cluster. miR17-92 transcription is altered in several different tumor types including lymphoma, leukemia, and of the breast and thyroid. As an intronic cluster, miR17-92 must be processed during splicing and therefore interaction between microprocessor and spliceosome machineries is of major importance in understanding its expression. Materials and methods We investigated the protein composition of spliceosomes assembled on pre-RNAs containing intronic miR18a and miR19a, components of the miR17-92 cluster, using mass spectrometry. Results Interestingly, we observed that proteins associated with intronic miR18a and miR19a are cell-specific, and are similar for both miRNAs analyzed. The only exception is the group of heterogeneous nuclear proteins that are commonly recruited by different cells. Conclusion miRNA processing depends on cell-specific proteins and heterogeneous nuclear proteins have a general role in miRNA processing from introns.

Made available in DSpace on 2018-11-29T03:50:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-11-21 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Skeletal myogenesis is a regulated process in which mononucleated cells, the myoblasts, undergo proliferation and differentiation. Upon differentiation, the cells align with each other, and subsequently fuse to form terminally differentiated multinucleated myotubes. Previous reports have identified the protein osteoglycin (Ogn) as an important component of the skeletal muscle secretome, which is expressed differentially during muscle development. However, the posttranscriptional regulation of Ogn by microRNAs during myogenesis is unknown. Bioinformatic analysis showed that miR-155 potentially targeted the Ogn transcript at the 3'-untranslated region (3' UTR). In this study, we tested the hypothesis that miR-155 inhibits the expression of the Ogn to regulate skeletal myogenesis. C2C12 myoblast cells were cultured and miR-155 overexpression or Ogn knockdown was induced by transfection with miR-155 mimic, siRNA-Ogn, and negative controls with lipofectamine for 15 hours. Near confluence (80-90%), myoblasts were induced to differentiate myotubes in a differentiation medium. Luciferase assay was used to confirm the interaction between miR-155 and Ogn 3' UTR. RT-qPCR and Western blot analyses were used to confirm that the differential expression of miR-155 correlates with the differential expression of myogenic molecular markers (Myh2, MyoD, and MyoG) and inhibits Ogn protein and gene expression in myoblasts and myotubes. Myoblast migration and proliferation were assessed using Wound Healing and MTT assays. Our results show that miR-155 interacts with the 3' UTR Ogn region and decrease the levels of Ogn in myotubes. The overexpression of miR-155 increased MyoG expression, decreased myoblasts wound closure rate, and decreased Myh2 expression in myotubes. Moreover, Ogn knockdown reduced the expression levels of MyoD, MyoG, and Myh2 in myotubes. These results reveal a novel pathway in which miR-155 inhibits Ogn expression to regulate proliferation and differentiation of C2C12 myoblast cells. Sao Paulo State Univ, Inst Biosci, Dept Morphol, Sao Paulo, Brazil Univ Sao Paulo, Inst Biomed Sci, Dept Cell & Dev Biol, Sao Paulo, Brazil Sao Paulo State Univ, Inst Biosci, Dept Morphol, Sao Paulo, Brazil FAPESP: 2012/13961-6 FAPESP: 2014/13783-6

About one half of malignant peripheral nerve sheath tumors (MPNST) have Neurofibromin 1 (NF1) mutations. NF1 is a tumor suppressor gene essential for negative regulation of RAS signaling. Survival for MPNST patients is poor and we sought to identify an effective combination therapy. Starting with the mTOR inhibitors rapamycin and everolimus, we screened for synergy in 542 FDA approved compounds using MPNST cells with a native NF1 loss in both alleles. We further analyzed the cell cycle and signal transduction. In vivo growth effects of the drug combination with local radiation therapy were assessed in MPNST xenografts. The synergistic combination of mTOR inhibitors with bortezomib yielded a reduction in MPNST cell proliferation. The combination of mTOR inhibitors and bortezomib also enhanced the anti-proliferative effect of radiation in vitro. In vivo, the combination of mTOR inhibitor (everolimus) and bortezomib with radiation therapy decreased tumor growth and proliferation, and augmented apoptosis. The combination of approved mTOR and proteasome inhibitors with radiation showed a significant reduction of tumor growth in an animal model and should be investigated and optimized further for MPNST therapy.

TCGA genomic study in papillary thyroid carcinoma (PTC) samples highlights two groups of tumors: BRAF-like and RAS-like, whose genotype might influence its biological behavior. The mechanisms behind progressive loss of thyroid differentiation, observed mainly in the most aggressive histotype anaplastic thyroid carcinoma (ATC), could be associated with the reactivation of embryonic signaling and acquisition of stem cell-like phenotype. In this study we focused on Notch and Nodal embryonic signaling pathways, which are crucial for stemness maintenance in embryonic cells and has also been linked to cancer cell stemness. By assessing the expression of Notch and Nodal pathway components in BRAF- and RAS-like cell lines, we sought to investigate if the reactivation of these pathways is involved in dedifferentiation mechanisms observed in ATC. For that purpose, RNA and protein were extracted from three PTC (TPC-1, BCPAP and K1), six ATC (KTC2, SW1736, C643, Hth7, Hth74 and Hth83) and non-tumoral (Nthy-ori 3-1) cell lines. For gene expression analysis, cDNA generate from mRNA was amplified by qPCR using specific primers for NOTCH1, NOTCH4, HES1, NUMB, CER1 and LEFTY1/2. For protein expression analysis, SDS-PAGE-fractionated proteins were transferred onto nitrocellulose membrane, incubated with anti-Nodal antibody and visualized by chemoluminescence. NOTCH1 was downregulated in BRAF-like PTC cell lines, while slightly overexpressed in RET/PTC-containing TPC-1. On the other hand, NOTCH1 was overexpressed in Hth83 and C643 ATC lines, both HRAS-mutated, and also in BRAF-mutated SW1736. NOTCH4 was overexpressed in PI3K-mutated K1 and all ATC cell lines. Transcription repressor HES1, which prevents cell cycle arrest by inhibiting p27, was highly expressed in all cell lines compared to Nthy. Levels of NUMB expression were elevated in all ATC cell lines with no difference between BRAF- and RAS-mutated, but were inversely related to those of HES1, as expected for a Notch pathway inhibitor. CER1 and LEFTY1/2, which encode Nodal inhibitors, were highly expressed in ATC cell lines (4/6 and 5/6, respectively) but with no apparent distinction between BRAF- and RAS-mutated cells. At the same time, Nodal protein levels are only upregulated in TP53-mutated BCPAP and C643, suggesting that alterations in MAPK components are not sufficient to promote Nodal overexpression. Our results show re-expression of Notch embryonic signaling components in both PTC and ATC cell lines with either BRAF or RAS oncogenes. Moreover, additional genetic alterations such as in PI3K and TP53 might also interfere with the expression of both Notch and Nodal components. We therefore highlight the importance of tumor genotype, which might determine the modulation of embryonic-related genes and therefore contribute to the undifferentiated phenotype in thyroid cancer. Financial support: FAPESP and CNPq. Citation Format: Paola M. Dantonio, Cesar Seigi Fuziwara, Kelly C. Saito, Edna T. Kimura. Expression of Notch and Nodal embryonic components in BRAF- and RAS-like thyroid cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1164.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:04:17Z No. of bitstreams: 1 S0004-27302013000300004.pdf: 141374 bytes, checksum: c57e14da8d45c97e5a8b0b82a2b58905 (MD5) Made available in DSpace on 2013-08-22T19:04:17Z (GMT). No. of bitstreams: 1 S0004-27302013000300004.pdf: 141374 bytes, checksum: c57e14da8d45c97e5a8b0b82a2b58905 (MD5) Previous issue date: 2013-04-01 Made available in DSpace on 2013-09-30T18:18:12Z (GMT). No. of bitstreams: 2 S0004-27302013000300004.pdf: 141374 bytes, checksum: c57e14da8d45c97e5a8b0b82a2b58905 (MD5) S0004-27302013000300004.pdf.txt: 39266 bytes, checksum: ab47b1ecfd79cbc70512fd13c3b0fe22 (MD5) Previous issue date: 2013-04-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:33:51Z No. of bitstreams: 2 S0004-27302013000300004.pdf: 141374 bytes, checksum: c57e14da8d45c97e5a8b0b82a2b58905 (MD5) S0004-27302013000300004.pdf.txt: 39266 bytes, checksum: ab47b1ecfd79cbc70512fd13c3b0fe22 (MD5) Made available in DSpace on 2014-05-20T13:33:51Z (GMT). No. of bitstreams: 2 S0004-27302013000300004.pdf: 141374 bytes, checksum: c57e14da8d45c97e5a8b0b82a2b58905 (MD5) S0004-27302013000300004.pdf.txt: 39266 bytes, checksum: ab47b1ecfd79cbc70512fd13c3b0fe22 (MD5) Previous issue date: 2013-04-01 O hipotireoidismo congênito (HC) é o distúrbio endócrino congênito mais frequente, com incidência variando de 1:2.000 a 1:4.000 crianças nascidas vivas e uma das principais causas de retardo mental que pode ser prevenida. Os Programas de Triagem Neonatal para a doença permitem a identificação precoce dos afetados e seu tratamento de modo a evitar as complicações da falta do hormônio. A maioria dos casos de hipotireoidismo congênito é decorrente de disgenesias tireoidianas (85%), entre elas a ectopia, hipoplasia ou agenesia tireoidianas, e os demais resultam de defeitos de síntese hormonal. As crianças afetadas (> 95%) geralmente não apresentam sintomas sugestivos da doença ao nascimento. Os sintomas e sinais mais comuns são: icterícia neonatal prolongada, choro rouco, letargia, movimentos lentos, constipação, macroglossia, hérnia umbilical, fontanelas amplas, hipotonia e pele seca. Várias estratégias são utilizadas para a triagem do HC. No Brasil, esta é obrigatória por lei e geralmente é feita com a dosagem de TSH em sangue seco coletado do calcanhar. A idade recomendada para sua realização é após as 48 horas de vida até o quarto dia. A confirmação diagnóstica é obrigatória com as dosagens de TSH e T4 livre ou T4 total. Congenital hypothyroidism (CH) is the most common congenital endocrine disorder, with an incidence of 1:2,000 to 1:4,000 live births and it is a leading preventable mental retardation. Neonatal Screening Programs allow early identification of the disease and the adequate treatment of affected children can avoid the complications related to deprivation of the hormone. Most cases of primary congenital hypothyroidism (85%) are due to thyroid dysgenesis (ectopia, hypoplasia or agenesis) while the remaining result from defects in hormone synthesis. Affected children (> 95%) usually have no symptoms suggesting the disease at birth. The most frequent symptoms and signs are prolonged neonatal jaundice, hoarse cry, lethargy, slow movements, constipation, macroglossia, umbilical hernia, large fontanelle, hypotonia and dry skin. Around the world, various strategies are used for the screening of the CH. In Brazil, screening for CH is mandatory by law and usually done by serum TSH in dried blood collected from the heel. The recommended age for performing this test is after 48 hours of life until the 4th day. Diagnostic confirmation is required dosing TSH and free T4 or total T4 in serum. Universidade de São Paulo Faculdade de Medicina de Ribeirão Preto Divisão de Endocrinologia e Metabologia USP Instituto de Ciências Biomédicas Universidade Estadual de São Paulo Faculdade de Medicina de Botucatu Departamento de Clínica Médica Universidade Federal de Santa Catarina Universidade Federal de Uberlândia (UFU) Departamento de Pediatria Unidade de Endocrinologia Pediátrica Universidade de São Paulo Faculdade de Medicina Departamento de Pediatria

MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression that modulate the vast majority of cellular processes. During development, the correct timing and expression of miRNAs in the tissue differentiation is essential for organogenesis and functionality. In thyroid gland, DICER and miRNAs are necessary for accurately establishing thyroid follicles and hormone synthesis. Moreover, DICER1 mutations and miRNA deregulation observed in human goiter influence thyroid tumorigenesis. The thyroid malignant transformation by MAPK oncogenes is accompanied by global miRNA changes, with a marked reduction of "tumor-suppressor" miRNAs and activation of oncogenic miRNAs. Loss of thyroid cell differentiation/function, and consequently iodine trapping impairment, is an important clinical characteristic of radioiodine-refractory thyroid cancer. However, few studies have addressed the direct role of miRNAs in thyroid gland physiology. Here, we focus on what we have learned in the thyroid follicular cell differentiation and function as revealed by cell and animal models and miRNA modulation in thyroid tumorigenesis.

Papillary Thyroid Cancer (PTC) is an endocrine malignancy in which BRAFV600E oncogenic mutation induces the most aggressive phenotype. In this way, considering that lncRNAs are arising as key players in oncogenesis, it is of high interest the identification of BRAFV600E-associated long noncoding RNAs, which can provide possible candidates for secondary mechanisms of BRAF-induced malignancy in PTC. In this study, we identified differentially expressed lncRNAs correlated with BRAFV600E in PTC and, also, extended the cohort of paired normal and PTC samples to more accurately identify differentially expressed lncRNAs between these conditions. Indirectly validated targets of the differentially expressed lncRNAs in PTC compared to matched normal samples demonstrated an involvement in surface receptors responsible for signal transduction and cell adhesion, as well as, regulation of cell death, proliferation and apoptosis. Targets of BRAFV600E-correlated lncRNAs are mainly involved in calcium signaling pathway, ECM-receptor interaction and MAPK pathway. In summary, our study provides candidate lncRNAs that can be either used for future studies related to diagnosis/prognosis or as targets for PTC management.

Nose is the first portion of the respiratory system into contact with air pollution particles, including organic compounds that could act as endocrine releasers. The objective was to identify and quantify estrogenic receptor-β (ERβ), aryl hydrocarbon receptor (AhR), the cytochrome P450 enzymes CYP1A1, 1A2, 1B1, and mucus profile in the nasal epithelium of mice. BALB/c mice male (n = 32) and female (n = 82) in proestrus, estrus and diestrus were divided into two groups: 1) exposed to ambient air; 2) concentrated ambient particles (CAPs) to achieve an accumulated dose (concentration vs. time product) of 600 μg/m(3), the time of the exposure was controlled to ensure the same concentration for all groups (5 days per week for 40-51 days). RT-PCR (Erβ-1, Erβ-2, Ahr, Cyp1a1, Cyp1a2, Cyp1b1), immunohistochemistry and morphometry (ERβ, AhR) were used to analyze. The mucus profiles were examined using acid (Alcian Blue) and neutral (periodic acid Schiff's) stains. Exposed females had significantly lower levels of Erβ-2 mRNA than exposed males (p = 0.036). Cyp1b1 mRNA in diestrus females was significantly lower in the CAP-exposed group compared with the ambient air group (p ≤ 0.05). ERβ expression in the epithelium and submucosa nucleus was lower in estrus exposed to CAPs compared with ambient air. CAPs increases AhR in the epithelium (p = 0.044) and submucosa (p = 0.001) nucleus of female when compared with male mice. Exposure to CAPs, also led to relatively increased acidic content in the mucus of males (p = 0.048), but decreased acidic content in that of females (p = 0.04). This study revealed sex-dependent responses to air pollution in the nasal epithelium that may partially explain the predisposition of females to airway respiratory diseases.

HighlightsTheoretical-practical study using Computer Aided Diagnosis and Morphometry concepts.The method aggregates the content of nuclei in microscopic images.The images are characterized by morphometric information and other attributes.The attributes were extracted using traditional object extraction algorithms.The method augments traditional image processing.Software allowed automatic classification of nuclei of thyroid in microscopic images. BackgroundThe analyses of several systems for medical-imaging processing typically support the extraction of image attributes, but do not comprise some information that characterizes images. For example, morphometry can be applied to find new information about the visual content of an image. The extension of information may result in knowledge. Subsequently, results of mappings can be applied to recognize exam patterns, thus improving the accuracy of image retrieval and allowing a better interpretation of exam results. Although successfully applied in breast lesion images, the morphometric approach is still poorly explored in thyroid lesions due to the high subjectivity thyroid examinations. ObjectiveThis paper presents a theoretical-practical study, considering Computer Aided Diagnosis (CAD) and Morphometry, to reduce the semantic discontinuity between medical image features and human interpretation of image content. MethodThe proposed method aggregates the content of microscopic images characterized by morphometric information and other image attributes extracted by traditional object extraction algorithms. This method carries out segmentation, feature extraction, image labeling and classification. Morphometric analysis was included as an object extraction method in order to verify the improvement of its accuracy for automatic classification of microscopic images. ResultsTo validate this proposal and verify the utility of morphometric information to characterize thyroid images, a CAD system was created to classify real thyroid image-exams into Papillary Cancer, Goiter and Non-Cancer. Results showed that morphometric information can improve the accuracy and precision of image retrieval and the interpretation of results in computer-aided diagnosis. For example, in the scenario where all the extractors are combined with the morphometric information, the CAD system had its best performance (70% of precision in Papillary cases). ConclusionResults signalized a positive use of morphometric information from images to reduce semantic discontinuity between human interpretation and image characterization.

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy and RET/PTC rearrangements represent key genetic events frequently associated to this cancer, enhancing proliferation and dedifferentiation by activation of the RET/PTC-RAS-BRAF-mitogen-activated protein kinase (MAPK) pathway. Recently, let-7 microRNA was found to reduce RAS levels in lung cancer, acting as a tumor suppressor gene. Here, we report that RET/PTC3 oncogenic activation in PCCL3 rat thyroid cells markedly reduces let-7f expression. Moreover, stable transfection of let-7 microRNA in TPC-1 cells, which harbor RET/PTC1 rearrangement, inhibits MAPK activation. As a result, let-7f was capable of reducing TPC-1 cell growth, and this might be explained, at least in part, by decreased messenger RNA (mRNA) expression of cell cycle stimulators such as MYC and CCND1 (cyclin D1) and increased P21 cell cycle inhibitor mRNA. In addition, let-7 enhanced transcriptional expression of molecular markers of thyroid differentiation such as TITF1 and TG. Thus, reduced expression of let-7f might be an essential molecular event in RET/PTC malignant transformation. Moreover, let-7f effects on thyroid growth and differentiation might attenuate neoplastic process of RET/PTC papillary thyroid oncogenesis through impairment of MAPK signaling pathway activation. This is the first functional demonstration of an association of let-7 with thyroid cancer cell growth and differentiation.

Papillary thyroid carcinoma (PTC) is frequently associated with a RET gene rearrangement that generates a RET/PTC oncogene. RET/PTC is a fusion of the tyrosine kinase domain of RET to the 5' portion of a different gene. This fusion results in a constitutively active MAPK pathway, which plays a key role in PTC development. The RET/PTC3 fusion is primarily associated with radiation-related PTC. Epidemiological studies show a lower incidence of PTC in radiation-exposed regions that are associated with an iodine-rich diet. Since the influence of excess iodine on the development of thyroid cancer is still unclear, the aim of this study is to evaluate the effect of high iodine concentrations on RET/PTC3-activated thyroid cells.PTC3-5 cells, a rat thyroid cell lineage harboring doxycycline-inducible RET/PTC3, were treated with 10(-3) M NaI. Cell growth was analyzed by cell counting and the MTT assay. The expression and phosphorylation state of MAPK pathway-related (Braf, Erk, pErk, and pRet) and thyroid-specific (natrium-iodide symporter [Nis] and thyroid-stimulating hormone receptor [Tshr]) proteins were analyzed by Western blotting. Thyroid-specific gene expression was further analyzed by quantitative reverse transcription (RT)-polymerase chain reaction.A significant inhibition of proliferation was observed, along with no significant variation in cell death rate, in the iodine-treated cells. Further, iodine treatment attenuated the loss of Nis and Tshr gene and protein expression induced by RET/PTC3 oncogene induction. Finally, iodine treatment reduced Ret and Erk phosphorylation, without altering Braf and Erk expression.Our results indicate an antioncogenic role for excess iodine during thyroid oncogenic activation. These findings contribute to a better understanding of the effect of iodine on thyroid follicular cells, particularly how it may play a protective role during RET/PTC3 oncogene activation.

We developed mice with germline endogenous expression of oncogenic Hras to study effects on development and mechanisms of tumor initiation. They had high perinatal mortality, abnormal cranial dimensions, defective dental ameloblasts, and nasal septal deviation, consistent with some of the features of human Costello syndrome. These mice developed papillomas and angiosarcomas, which were associated with Hras G12V allelic imbalance and augmented Hras signaling. Endogenous expression of Hras G12V was also associated with a higher mutation rate in vivo. Tumor initiation by Hras G12V likely requires augmentation of signal output, which in papillomas and angiosarcomas is achieved via increased Hras -gene copy number, which may be favored by a higher mutation frequency in cells expressing the oncoprotein.

The Notch signaling cascade is deregulated in diverse cancer types. Specific Notch function in cancer is dependent on the cellular context, the particular homologs expressed, and cross-talk with other signaling pathways. We have previously shown that components of the Notch signaling pathway are deregulated in meningiomas. How-ever, the functional consequence of abnormal Notch signaling to meningiomas is unknown. Here, we report that exogenous expression of the Notch pathway effector, HES1, is associated with tetraploid cells in meningioma cell lines. Activated Notch1 and Notch2 receptors induced endogenous HES1 expression and were associated with tetraploidy in meningiomas. Tetraploid meningioma cells exhibited nuclear features of chromosomal instability and increased frequency of nuclear atypia, such as multipolar mitotic spindles and accumulation of cells with large nuclei. FACS-sorted tetraploid cells are viable but have higher rates of spontaneous apoptosis when compared with diploid cells. We have used spectral karyotyping to show that, in contrast to diploid cells, tetraploid cells develop a higher number of both numerical and structural chromosomal abnormalities. Our findings identify a novel function for the Notch signaling pathway in generating tetraploidy and contributing to chromosomal instability. We speculate that abnormal Notch signaling pathway is an initiating genetic mechanism for meningioma and potentially promotes tumor development.

Meningioma tumor growth involves the subarachnoid space that contains the cerebrospinal fluid. Modeling tumor growth in this microenvironment has been associated with widespread leptomeningeal dissemination, which is uncharacteristic of human meningiomas. Consequently, survival times and tumor properties are varied, limiting their utility in testing experimental therapies. We report the development and characterization of a reproducible orthotopic skull-base meningioma model in athymic mice using the IOMM-Lee cell line. Localized tumor growth was obtained by using optimal cell densities and matrigel as the implantation medium. Survival times were within a narrow range of 17-21 days. The xenografts grew locally compressing surrounding brain tissue. These tumors had histopathologic characteristics of anaplastic meningiomas including high cellularity, nuclear pleomorphism, cellular pattern loss, necrosis and conspicuous mitosis. Similar to human meningiomas, considerable invasion of the dura and skull and some invasion of adjacent brain along perivascular tracts were observed. The pattern of hypoxia was also similar to human malignant meningiomas. We use bioluminescent imaging to non-invasively monitor the growth of the xenografts and determine the survival benefit from temozolomide treatment. Thus, we describe a malignant meningioma model system that will be useful for investigating the biology of meningiomas and for preclinical assessment of therapeutic agents.

TGFbeta e activina são membros da superfamília TGFbeta e desempenham um amplo papel no desenvolvimento, proliferação e apoptose. Estes fatores de crescimento exercem seus efeitos biológicos ligando-se a receptores de membrana do tipo I e do tipo II que transduzem a sinalização até o núcleo através da fosforilação das proteínas R-SMADs (SMAD 2/3) e co-SMADs (SMAD4). O controle apropriado da via de TGFbeta/activina ainda depende da regulação negativa exercida pelo SMAD inibitório (SMAD7) e pelas enzimas E3 de ubiquitinação (Smurfs). Fisiologicamente, TGFbeta e activina atuam como potentes inibidores da proliferação na célula folicular tiroidiana. Desta forma, alterações de receptores e componentes da via de sinalização SMAD estão associadas a diferentes tipos de tumores. Desde que TGFbeta e activina geram sua sinalização intracelular utilizando os mesmos componentes da via SMAD, o desequilíbrio desta via prejudica dois processos anti-mitogênicos da célula. Nesta revisão, enfocamos aspectos que indicam o mecanismo de resistência ao efeito inibitório de TGFbeta e activina ocasionado pelo desequilíbrio da via de sinalização SMAD nas neoplasias da tiróide. TGFbeta and activin are members of the TGFbeta superfamily and play a wide role in development, proliferation and apoptosis. These growth factors exert their biological effects by binding to the type I and II membrane receptors to transduce their signalling through the nucleus by phosphorylation of R-SMADs (SMAD 2/3) and co-SMADs (Smad 4). The proper control of TGFbeta/activin pathway is negatively regulated by inhibitory SMAD (SMAD7) and by E3 ubiquitination enzymes (Smurfs). Physiologically, TGFbeta and activin act as potent growth inhibitors in thyroid follicular cell. Thus, alterations in the receptors and components of SMAD signalling pathway are associated with several types of tumors. Since TGFbeta and activin generate their intracellular signalling through the same components of the SMAD pathway, the unbalance of this pathway impairs both of anti-mitogenic signals in the cell. This review addresses aspects of the molecular mechanisms in the understanding of resistance to the growth inhibitory effects of TGFbeta and activin due to the disequilibrium in the SMAD inhibitory pathway in thyroid neoplasia.

Background/Aims: Thyroid hormone (TH) signalling is critical for heart function. The heart expresses thyroid hormone receptors (THRs); THRα1 and THRβ1. We aimed to investigate the regulation mechanisms of the THRβ isoform, its association with gene expression changes and implications for cardiac function. Methods: The experiments were performed using adult male mice expressing TRβΔ337T, which contains the Δ337T mutation of the human THRB gene and impairs ligand binding. Cardiac function and RNA expression were studied after hypo-or hyperthyroidism inductions. T3-induced cardiac hypertrophy was not observed in TRβΔ337T mice, showing the fundamental role of THRβ in cardiac hypertrophy. Results: We identified a group of independently regulated THRβ genes, which includes Adrb2, Myh7 and Hcn2 that were normally regulated by T3 in the TRβΔ337T group. However, Adrb1, Myh6 and Atp2a2 were regulated via THRβ. The TRβΔ337T mice exhibited a contractile deficit, decreased ejection fraction and stroke volume, as assessed by echocardiography. In our model, miR-208a and miR-199a may contribute to THRβ-mediated cardiac hypertrophy, as indicated by the absence of T3-regulated ventricular expression in TRβΔ337T mice. Conclusion: THRβ has important role in the regulation of specific mRNA and miRNA in T3-induced cardiac hypertrophic growth and in the alteration of heart functions.

MicroRNAs (miRNAs) representam uma nova classe de RNAs endógenos de ~22 nucleotídeos, que atuam como silenciadores pós-transcricionais, inibindo a tradução de RNAs mensageiros-alvo. Descobertos há pouco mais de uma década em Caenorhabditis elegans, os miRNAs são hoje reconhecidos como reguladores fundamentais da expressão gênica em plantas e animais. Até o momento, identificaram-se 462 genes de miRNA no genoma humano e estima-se que esse número supere 1000 miRNAs distintos. Análises bioinformáticas indicam que um único miRNA atue em diversos RNAs mensageiros, influenciando múltiplas vias de sinalização concomitantemente e apresentando enorme potencial regulatório. Apesar da biologia dos miRNAs ser ainda pouco entendida, essas moléculas já foram relacionadas a diversos processos biológicos. Além disso, a expressão anômala destes pequenos RNAs tem sido associada a diferentes patologias humanas, inclusive aquelas relacionadas ao sistema endócrino e câncer.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:58:43Z No. of bitstreams: 1 S0004-27302006000300019.pdf: 83972 bytes, checksum: 892aaea7a03ec59d0984eaf5201d2b42 (MD5) Made available in DSpace on 2013-08-22T18:58:43Z (GMT). No. of bitstreams: 1 S0004-27302006000300019.pdf: 83972 bytes, checksum: 892aaea7a03ec59d0984eaf5201d2b42 (MD5) Previous issue date: 2006-06-01 Made available in DSpace on 2013-09-30T19:54:41Z (GMT). No. of bitstreams: 2 S0004-27302006000300019.pdf: 83972 bytes, checksum: 892aaea7a03ec59d0984eaf5201d2b42 (MD5) S0004-27302006000300019.pdf.txt: 34663 bytes, checksum: 0ded15e711cb48b77106764e342b0fb4 (MD5) Previous issue date: 2006-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:14:13Z No. of bitstreams: 2 S0004-27302006000300019.pdf: 83972 bytes, checksum: 892aaea7a03ec59d0984eaf5201d2b42 (MD5) S0004-27302006000300019.pdf.txt: 34663 bytes, checksum: 0ded15e711cb48b77106764e342b0fb4 (MD5) Made available in DSpace on 2014-05-20T15:14:13Z (GMT). No. of bitstreams: 2 S0004-27302006000300019.pdf: 83972 bytes, checksum: 892aaea7a03ec59d0984eaf5201d2b42 (MD5) S0004-27302006000300019.pdf.txt: 34663 bytes, checksum: 0ded15e711cb48b77106764e342b0fb4 (MD5) Previous issue date: 2006-06-01 A incidência do câncer diferenciado da tiróide vem aumentando há várias décadas no Brasil, assim como em todo o mundo. A popularização de métodos diagnósticos sensíveis e de uso relativamente simples tem contribuído para o diagnóstico cada vez mais freqüente de carcinomas de pequeno tamanho. Uma parte destes tumores ocorre em pacientes denominados de baixo risco, que poderiam se beneficiar de estratégias de conduta menos agressivas. Entretanto, a definição de baixo risco ainda é confusa e não existem meios seguros para distinguir os pacientes que evoluirão de forma pior dos demais. Por outro lado, o uso de novos métodos de acompanhamento vem mudando a maneira de conduzir estes casos. Um grupo multidisciplinar que inclui pesquisadores básicos, endocrinologistas, médicos nucleares, cirurgiões e patologistas endócrinos reviu a literatura pertinente e, com base em sua experiência, propõe algumas normas de conduta no carcinoma diferenciado da tiróide chamado de baixo risco em nosso meio. The trend of increasing thyroid cancer has been recognized in Brazil as well as all over the world for several decades. The large use of simple and effective diagnostic tools has significantly contributed to this trend. It is estimated that small carcinomas found at surgery for benign thyroid disorders and by ultrasonography will be identified at grater frequency in the further years. Part of these tumors occurs in low-risk patients that may benefit of less aggressive management strategies. However, the characterization of low-risk patient is still confusing and we lack adequate markers to tell apart patients that may present a troublesome progression of the disease. Furthermore, the use of new follow-up methods has recently changed some guidelines. A multidisciplinary team, including basic scientists, endocrinologists, nuclear medicine physicians, thyroid surgeons and endocrine pathologists reviewed the pertinent literature and, based on their experience, propose some management guidelines for Brazilian patients with low-risk thyroid carcinomas. Universidade Estadual de Campinas/UNICAMP Faculdade de Ciências Médicas Departamento de Clínica Médica Universidade Estadual de Campinas/UNICAMP Faculdade de Ciências Médicas Departamento de Cirurgia Universidade Estadual de Campinas/UNICAMP Faculdade de Ciências Médicas Departamento de Anatomia Patológica Sociedade Brasileira de Biologia e Medicina Nuclear Santa Casa de Misericórdia de São Paulo Universidade de São Paulo/FMUSP Faculdade de Medicina Departamento de Clínica Médica Universidade de São Paulo/FMUSP Faculdade de Medicina Centro de Medicina Nuclear Universidade de Santo Amaro/ UNISA Faculdade de Medicina Departamento de Cirurgia Universidade de São Paulo Instituto de Ciências Biológicas Departamento de Fisiologia e Biofísica Universidade de São Paulo Instituto de Ciências Biológicas Universidade Estadual Paulista Faculdade de Medicina Departamento de Clínica Médica Universidade Estadual Paulista Faculdade de Medicina Departamento de Clínica Médica

Differentiated thyroid cancers (papillary - PTC and follicular - FTC) are the most common endocrine malignancies. The recent progresses in the understanding of PTC and FTC pathogenesis are summarized in this review. In PTC, a single mutation of BRAF (the gene for the B-type Raf kinase) (V600E) is responsible for the disease in 40-50% of patients, especially in older people and is associated with a poorer clinicopathological outcome. Due to these characteristics, its use as a specific diagnostic and prognostic marker for PTC in cytological specimens is being implemented. Another important cause of PTC is rearrangements of the RET tyrosine kinase receptor (RET/PTC), which represent a recombination of the promoter and N-terminal domain of a partner gene with the C-terminal region of the RET gene, resulting in a chimeric gene with a protein product containing a constitutively activated RET tyrosine kinase, responsible for 20-30% patients, specially the younger or after radiation. The pathogenesis of FTC is less understood. A chromosomal translocation between the transcription factor PAX8 and the peroxisome proliferator-activated receptorgamma (PPARgamma) occurs in 30-50% of patients; however, the presence of PAX8-PPARgamma is also demonstrated in follicular adenomas. Therefore, there is no complete evidence that PAX8-PPARgamma is the cause of FTC. Another finding in FTC is mutations on the RAS gene, which excludes PAX8-PPARgamma rearrangements. Several genes, as TRgamma, PTEN, PKAR1A, DDIT3, ARG2, ITM1 and C1orf24 - some discovered by techniques of differential gene expression -, have been recently implicated in the pathogenesis of FTC.

A função do eixo hipotálamo-hipófise-tireóide em animais portadores da "síndrome do T3 baixo", foi estudada em ratos implantados com o tumor de Walker-256. Ratos machos adultos foram injetados com 1 x 106 células tumorais viáveis, por via SC, e sacrificados após 10 dias. A intensidade da síndrome guardou relação positiva com o tamanho do tumor desenvolvido. Houve diminuição da atividade tireoideana documentada pela diminuição da área nuclear das células foliculares, das concentrações plasmáticas do T4, da rTg e da captação do 131I. Mesmo o implante SC de um pellet de TSH de liberação lenta causou menor estimulação tireoideana, avaliada após 2 e 24h nos ratos com tumor. A secreção do rTSH avaliada através da administração IV de TRH mostrou-se significativamente diminuída nestas condições, indicando aumento do tônus inibidor hipotalâmico sobre a secreção deste hormônio. A participação de outros neuro-mediadores hipotalâmicos foi verificada através da administração prévia de metoclopramida e/ou fisostigmina, com ou sem estímulo subseqüente pelo TRH. Nos animais tratados com metoclopramida, os valores do rTSH aumentaram significativamente, assim como a resposta ao estímulo de secreção pelo TRH. A fisostigmina mostrou-se mais eficiente na mediação da resposta de secreção do rTSH, bem como na resposta ao estímulo de secreção pelo TRH. A administração concomitante dos dois fármacos, seguida do estímulo pelo TRH, normalizou a secreção do rTSH. Conclui-se que, além das alterações conhecidas do metabolismo das iodotironinas, a secreção de TSH encontra-se diminuída nos animais portadores de tumor de Walker-256, sugerindo diminuição global do tônus tireoideano.

OBJETIVO: Avaliar, no coração, por imuno-histoquímica, a localização das proteínas TGFbeta1 latente e TGFbeta1 ativa, se ocorre ativação radioinduzida da proteína TGFbeta1 latente, e a distribuição das fibras colágenas em diversos períodos de tempo após irradiação. MATERIAIS E MÉTODOS: Trinta e dois camundongos isogênicos (C57BL) foram divididos em dois grupos: GI (não irradiado), com 12 animais, e GII (irradiado), com 20 animais. Os animais do GII receberam radiação gama (telecobaltoterapia, 60Co, com rendimento de 0,97 Gy/min., dose única de 7 Gy em corpo inteiro). Os camundongos dos grupos I e II foram sacrificados por estiramento cervical nos períodos de 1, 14, 30 e 90 dias após irradiação. RESULTADOS: Os corações irradiados apresentaram: 1) alterações nucleares e diminuição das estriações das células musculares cardíacas; 2) aumento significante da deposição de fibras colágenas aos 90 dias depois da irradiação; 3) ativação da proteína TGFbeta1 latente em cardiomiócitos e células do conjuntivo depois da irradiação. CONCLUSÃO: Nossos resultados mostram a importância da proteína TGFbeta1 no processo de fibrose cardíaca radioinduzida e sugerem que células do parênquima (cardiomiócitos) e do conjuntivo podem participar deste mecanismo atuando como fontes da proteína TGFbeta1 ativa.OBJECTIVE: To assess the latent and active TGFbeta1 localization in the heart, to evaluate whether or not radiation induces latent TGFbeta1 activation, and to study the distribution of collagen fibers in the irradiated heart. MATERIALS AND METHODS: Thirty-two C57BL mice were randomly assigned in two groups: GI (non irradiated animals) and GII (irradiated animals). The mice from GII received a single whole-body radiation dose of 7Gy, using a 60Co source at a dose rate of 0.97 Gy/min. The animals were sacrificed by cervical dislocation at 1, 14, 30 and 90 days after irradiation. RESULTS: The irradiated hearts showed: 1) nuclear changes and muscle cells with decreased striations; 2) significant increase in the collagen deposition 90 days after irradiation; 3) latent TGFbeta1 activation in the cardiomyocytes and connective tissue cells after irradiation. CONCLUSION: Our results show the importance of TGFbeta1 protein in the process of radiation-induced heart fibrosis and suggest that cardiomyocytes and connective cells may play a role in this mechanism acting as cellular sources of active TGFbeta1.