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  • Possui Livre-docência em Neurologia pela Universidade de São Paulo (2001). Doutorado em Neurologia pela Universidade ... moreedit
Spinal muscular atrophy (SMA), the second most common lethal autosomal recessive disorder, has an incidence of 1:10,000 newborns. SMA is divided into acute (Werdnig-Hoffmann disease, type I), intermediate (type II) and juvenile forms... more
Spinal muscular atrophy (SMA), the second most common lethal autosomal recessive disorder, has an incidence of 1:10,000 newborns. SMA is divided into acute (Werdnig-Hoffmann disease, type I), intermediate (type II) and juvenile forms (Kugelberg-Welander disease, type III). The gene of all three forms of SMA maps to chromosome 5q 11.2-13.3. Two candidate genes, the survival motor neuron (SMN) gene and the neuronal apoptosis inhibitory protein (NAIP) gene, have been identified; SMN is deleted in most SMA patients. We studied both genes in 87 Brazilian SMA patients (20 type I, 14 type II and 53 type III) from 74 unrelated families, by using PCR and single strand conformation polymorphism (SSCP). Deletions of exons 7 and/or 8 of the SMN gene were found in 69% of the families: 16/20 in type I, 9/12 in type II and 26/42 in type III. Among 51 families with deletions, 44 had both exons deleted while seven had deletions only of exon 7. Deletions of exon 5 of the NAIP gene were found in 7/20 ...
Glioblastoma (GBM) is an aggressive brain cancer associated with poor overall survival. The metabolic status and tumor microenvironment of GBM cells have been targeted to improve therapeutic strategies. TLR4 is an important innate immune... more
Glioblastoma (GBM) is an aggressive brain cancer associated with poor overall survival. The metabolic status and tumor microenvironment of GBM cells have been targeted to improve therapeutic strategies. TLR4 is an important innate immune receptor capable of recognizing pathogens and danger-associated molecules. We have previously demonstrated the presence of TLR4 in GBM tumors and the decreased viability of the GBM tumor cell line after lipopolysaccharide (LPS) (TLR4 agonist) stimulation. In the present study, metformin (MET) treatment, used in combination with temozolomide (TMZ) in two GBM cell lines (U87MG and A172) and stimulated with LPS was analyzed. MET is a drug widely used for the treatment of diabetes and has been repurposed for cancer treatment owing to its anti-proliferative and anti-inflammatory actions. The aim of the study was to investigate MET and LPS treatment in two GBM cell lines with different metabolic statuses. MET treatment led to mitochondrial respiration blu...
Adrenocortical carcinoma (ACC) is a rare, aggressive, and poorly understood cancer of the adrenal cortex. Abnormal epigenetic patterning is a major predictor of dismal disease outcomes. Patients with genome-wide CpG island... more
Adrenocortical carcinoma (ACC) is a rare, aggressive, and poorly understood cancer of the adrenal cortex. Abnormal epigenetic patterning is a major predictor of dismal disease outcomes. Patients with genome-wide CpG island hypermethylation (CIMP-high) experience rapidly recurrent and routinely fatal disease. A deeper understanding of how epigenetic programs coordinate tumorigenesis is essential to develop improved medical therapies. We identify that DNA hypermethylation is directed to targets of a histone modifying complex, PRC2, suggesting cross-talk between DNA and histone methylation in CIMP-high ACC. In contrast to our expectations, we discovered that DNA methylation and PRC2-directed histone methylation are mutually exclusive. Additionally, we identified that EZH2 (a canonical member of the PRC2) forms a separate complex with tissue-specific proteins to coordinate sustained proliferation and steroidogenic differentiation in vitro and in vivo. These complexes persist through adv...
Background Supratentorial RELA fusion (ST-RELA) ependymomas (EPNs) are resistant tumors without an approved chemotherapeutic treatment. Unfortunately, the molecular mechanisms that lead to chemoresistance traits of ST-RELA remain elusive.... more
Background Supratentorial RELA fusion (ST-RELA) ependymomas (EPNs) are resistant tumors without an approved chemotherapeutic treatment. Unfortunately, the molecular mechanisms that lead to chemoresistance traits of ST-RELA remain elusive. The aim of this study was to assess RELA fusion-dependent signaling modules, specifically the role of the Hedgehog (Hh) pathway as a novel targetable vulnerability in ST-RELA. Methods Gene expression was analyzed in EPN from patient cohorts, by microarray, RNA-seq, qRT-PCR, and scRNA-seq. Inhibitors against Smoothened (SMO) (Sonidegib) and Aurora kinase A (AURKA) (Alisertib) were evaluated. Protein expression, primary cilia formation, and drug effects were assessed by immunoblot, immunofluorescence, and immunohistochemistry. Results Hh components were selectively overexpressed in EPNs induced by the RELA fusion. Single-cell analysis showed that the Hh signature was primarily confined to undifferentiated, stem-like cell subpopulations. Sonidegib exh...
Limb-girdle muscular dystrophy presents with heterogeneous clinical and molecular features. The primary characteristic of this disorder is proximal muscular weakness with variable age of onset, speed of progression, and intensity of... more
Limb-girdle muscular dystrophy presents with heterogeneous clinical and molecular features. The primary characteristic of this disorder is proximal muscular weakness with variable age of onset, speed of progression, and intensity of symptoms. Sarcoglycanopathies, which are a subgroup of the limb-girdle muscular dystrophies, are caused by mutations in sarcoglycan genes. Mutations in these genes cause secondary deficiencies in other proteins, due to the instability of the dystrophin-glycoprotein complex. Therefore, determining the etiology of a given sarcoglycanopathy requires costly and occasionally inaccessible molecular methods. The aim of this study was to identify phenotypic differences among limb-girdle muscular dystrophy patients who were grouped according to the immunohistochemical phenotypes for the four sarcoglycans. To identify phenotypic differences among patients with different types of sarcoglycanopathies, a questionnaire was used and the muscle strength and range of mot...
Medulloblastomas are the most common malignant tumors of the central nervous system in childhood. The incidence is about 19-20% between children younger than 16 years old with peak incidence between 4 and 7 years. Despite its sensibility... more
Medulloblastomas are the most common malignant tumors of the central nervous system in childhood. The incidence is about 19-20% between children younger than 16 years old with peak incidence between 4 and 7 years. Despite its sensibility to no specific therapeutic means like chemotherapy and radiotherapy, the treatment is very aggressive and frequently results in regression, growth deficit, and endocrine dysfunction. From this point of view, new treatment approaches are needed such as molecular targeted therapies. Studies in glioblastoma demonstrated that ASPM gene was overexpressed when compared to normal brain and ASPM inhibition by siRNA-mediated inhibits tumor cell proliferation and neural stem cell proliferation, supporting ASPM gene as a potential molecular target in glioblastoma. The aim of this work was to evaluate ASPM expression in medulloblastoma fragment samples, and to compare the results with the patient clinical features. Analysis of gene expression was performed by quantitative PCR real time using SYBR Green system in tumor samples from 37 children. The t test was used to analyze the gene expression, and Mann-Whitney test was performed to analyze the relationship between gene expressions and clinical characteristics. Kaplan-Meier test evaluated curve survival. All samples overexpressed ASPM gene more than 40-fold. However, we did not find any association between the overexpressed samples and the clinical parameters. ASPM overexpression may modify the ability of stem cells to differentiate during the development of the central nervous system, contributing to the development of medulloblastoma, a tumor of embryonic origin from cerebellar progenitor cells.
PURPOSE: It has been suggested that mitochondrial disease may be responsible for a substantial proportion of strokes of indetermined origin. We have preliminarily screened for MELAS (mitochondrial encephalomyopathy, lactic acidosis, and... more
PURPOSE: It has been suggested that mitochondrial disease may be responsible for a substantial proportion of strokes of indetermined origin. We have preliminarily screened for MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) mutations in young patients with cryptogenic strokes. METHOD: The mitochondrial mutations A3243G and T3271C were investigated in 38 subjects aged less than 46 years. Group 1: 15 patients with cryptogenic strokes; Group 2: 3 patients with diagnosis of MELAS syndrome, including stroke-like episodes; Group 3: 20 healthy subjects. RESULTS: The A3243G mutation was absent in all subjects in Groups 1 and 3 but was present in all subjects in Group 2. CONCLUSION: Our results do not support screening for these mutations to diagnose oligosymptomatic forms of MELAS in cryptogenic strokes in the absence of other features of the syndrome. We suggest that clinical findings should guide mitochondrial genetic testing.
Pompe's disease (PD) is a metabolic myopathy caused by the accumulation of lysosomal glycogen, secondary to acid α-glucosidase (GAA) enzyme deficiency. Childhood and late-onset forms are described, differing by the age of onset and... more
Pompe's disease (PD) is a metabolic myopathy caused by the accumulation of lysosomal glycogen, secondary to acid α-glucosidase (GAA) enzyme deficiency. Childhood and late-onset forms are described, differing by the age of onset and symptoms. In this study were analyzed affected siblings with Pompe's disease (PD) and their distinct clinical and pathological presentations. METHOD: Diagnosis was performed by the clinical presentation of limb-girdle dystrophies and respiratory compromise. Confirmatory diagnoses were conducted by muscle biopsy, GAA activity measurement and by GAA gene genotyping. RESULTS: The findings suggested muscular involvement due to GAA deficiency. GAA genotyping showed they are homozygous for the c.-32-3C>A mutation. CONCLUSION: Herein we reported a family where three out of five siblings were diagnosed with late-onset PD, although it is a rare metabolic disease inherited in an autossomal recessive manner. We emphasize the importance of including this p...
Medulloblastoma is the most common childhood malignant tumor of central nervous system, but it may also occur in adults. It presents high invasive growth with spreading of tumor cells into the leptomeningeal space along the neuroaxis... more
Medulloblastoma is the most common childhood malignant tumor of central nervous system, but it may also occur in adults. It presents high invasive growth with spreading of tumor cells into the leptomeningeal space along the neuroaxis early in the course of the disease. Extraneural metastases are rare but frequently lethal, occurring only in 1 to 5% of patients, and are related, in the most of cases, to the presence of ventriculoperitoneal shunt. Here we characterize the clinical profile of five cases of medulloblastoma with systemic spreading of tumor cells, also comparing them to cases already described in the literature.
We report on two boys aged 2 and 6 years-old respectively with dysmorphic face, ptosis, down-slanting palpebral fissures, hypertelorism, epicanthic folds, low-set ears, malar hypoplasia, micrognathia, high-arched palate, clinodactyly,... more
We report on two boys aged 2 and 6 years-old respectively with dysmorphic face, ptosis, down-slanting palpebral fissures, hypertelorism, epicanthic folds, low-set ears, malar hypoplasia, micrognathia, high-arched palate, clinodactyly, palmar simian line, pectus excavatum, winging of the scapulae, lumbar lordosis and mild thoracic scoliosis who present congenital hypotonia, slightly delayed motor development, diffuse joint hyperextensibility and mild proximal weakness. The muscle biopsy revealed minimal but identifiable changes represented by size fiber variability, type I fiber predominance and atrophy, perimysial fibrous infiltration and some disarray of the intermyofibrillary network. These cases correspond to the first Brazilian reports of the King-Denborough syndrome and our objective is increasing the awareness of this disorder as these patients are predisposed to developing malignant hyperthermia.
OBJETIVO: Os dados são conflitantes em relação a risco de acidente cerebrovascular associado a polimorfismo do gene 5,10-metilenetetrahidrofolato redutase C677T, o qual predispõe a hiperhomocisteinemia. Um estudo de meta-análise sugere... more
OBJETIVO: Os dados são conflitantes em relação a risco de acidente cerebrovascular associado a polimorfismo do gene 5,10-metilenetetrahidrofolato redutase C677T, o qual predispõe a hiperhomocisteinemia. Um estudo de meta-análise sugere que o genotipo 5,10-metilenetetrahidrofolato redutase 677TT poderia ter uma pequena influência em determinar susceptibilidade a acidente cerebrovascular. MÉTODOS: Analisamos este polimorfismo em indivíduos brasileiros com acidente cerebrovascular isquêmico, baseando-se em um estudo de caso-controle. RESULTADOS: Comparamos os genótipos 5,10-metilenetetrahidrofolato redutase em grupos de indivíduos com acidente cerebrovascular isquêmico (n=127) e controle normal (n=126), e encontramos Odds Ratio de 1,97 (IC 95% 0,84 - 4,64) em uma análise multivariada, na qual os resultados foram ajustados a características clínicas basais dos indivíduos estudados. DISCUSSÃO: Nossos estudos indicam que o genótipo 5,10-metilenetetrahidrofolato redutase C677T não é um fat...
Objective To study the prevalence and natural evolution of arrhythmic events and conduction disturbances in myotonic dystrophy; to corre-late the genetic defect with cardiovascular findings; to assess cardiac mortality, frequency, and... more
Objective To study the prevalence and natural evolution of arrhythmic events and conduction disturbances in myotonic dystrophy; to corre-late the genetic defect with cardiovascular findings; to assess cardiac mortality, frequency, and predictive factors of sudden death; to correlate the severity of the neuromuscular and cardiac involvement; and to define the role of the electrophysiological study (EPS), in myotonic dystrophy. Methods Periodic clinical assessment and the following tests were performed in 83 consecutive patients with a mean follow-up of 42±30.63 months: complementary examinations, genetic tests, electrocardiography, echocardiography, and Holter; electrophy-siological study was performed in 59 cases.
Background This study investigated the prevalence of risk factors associated with the metabolic syndrome (MetSyn) among individuals of Japanese descent exposed to different cultural environments. Design A cross-sectional study to assess... more
Background This study investigated the prevalence of risk factors associated with the metabolic syndrome (MetSyn) among individuals of Japanese descent exposed to different cultural environments. Design A cross-sectional study to assess component risk factors for the diagnosis of MetSyn was undertaken in urban areas in Japan and Brazil. A total of 773 men and women aged 35 years or over were included in three groups: 249 native Japanese, 269 Brazilian individuals of Japanese ancestry residing in Japan, and 255 Brazilian individuals of Japanese ancestry residing in Brazil. Results Higher rates of metabolic abnormalities with respect to central obesity and serum lipid profiles were observed among Brazilian individuals of Japanese ancestry residing in Brazil compared with those residing in Japan and native Japanese. Likewise, an increased risk of hypertension was observed among Japanese Brazilian individuals residing in Japan. The prevalence of MetSyn in men was significantly higher am...
A estimulação magnética trancraniana (EMT) é técnica não invasiva de investigação e modulação da excitabilidade cortical em humanos. Alterações de excitabilidade cortical em circunstâncias fisiológicas e patológicas podem ser avaliadas... more
A estimulação magnética trancraniana (EMT) é técnica não invasiva de investigação e modulação da excitabilidade cortical em humanos. Alterações de excitabilidade cortical em circunstâncias fisiológicas e patológicas podem ser avaliadas através de medidas como limiar motor, potencial evocado motor, curvas de recrutamento, inibição e facilitação intracorticais. O tempo de condução motora central pode estimar a transmissão de impulsos neurais em vias motoras. Mudanças em áreas de representação do córtex sensorimotor podem ser estudadas por mapeamento cortical. A modulação do processamento de diferentes áreas corticais, através da EMT, possibilita o estudo de diferentes funções cerebrais. Aplicações terapêuticas da EMT em depressão, doença de Parkinson e epilepsia têm atraído grande interesse na última década. A integração de EMT a técnicas neurofisiológicas e de neuroimagem oferece possibilidades promissoras de mapeamento cortical não invasivo. A EMT apresenta grande potencial como ins...
Ependymomas are tumors of the CNS. Although cyclin D1 overexpression has been related to several cancers, its prognostic value in ependymomas has not yet been fully established. We evaluated cyclin D1 expression by an immunohistochemistry... more
Ependymomas are tumors of the CNS. Although cyclin D1 overexpression has been related to several cancers, its prognostic value in ependymomas has not yet been fully established. We evaluated cyclin D1 expression by an immunohistochemistry analysis of 149 samples of ependymomas, including some relapses, corresponding to 121 patients. Eighty-one patients were adults, 60 were intracranial cases and 92 tumors were grade II. Gross total resection (GTR) was achieved in 62% of cases, and relapse was confirmed in 41.4% of cases. Cyclin D1 protein expression was analyzed by immunohistochemistry and scored with a labeling index (LI) calculated as the percentage of positively stained cells by intensity. We also analyzed expression of CCND1 and NOTCH1 in 33 samples of ependymoma by quantitative real-time PCR. A correlation between cyclin D1 LI score and anaplastic cases (P < 0.001), supratentorial location (P < 0.001) and age (P = 0.001) were observed. A stratified analysis demonstrated that cyclin D1 protein expression was strong in tumors with a supratentorial location, independent of the histological grade or age. Relapse was more frequent in cases with a higher cyclin D1 LI score (P = 0.046), and correlation with progression-free survival was observed in cases with GTR (P = 0.002). Only spinal canal tumor location and GTR were suggestive markers of PFS in multivarite analyses. Higher expression levels were observed in anaplastic cases for CCND1 (P = 0.002), in supratentorial cases for CCND1 (P = 0.008) and NOTCH1 (P = 0.011). There were correlations between the cyclin D1 mRNA and protein expression levels (P < 0.0001) and between CCND1 and NOTCH1 expression levels (P = 0.003). Higher cyclin D1 LI was predominant in supratentorial location and predict relapse in GTR cases. Cyclin D1 could be used as an immunohistochemical marker to guide follow-up and treatment in these cases.
Astrocytoma is the most common and aggressive tumor of the central nervous system. Genetic and environmental factors, bacterial infection, and several other factors are known to be involved in gliomagenesis, although the complete... more
Astrocytoma is the most common and aggressive tumor of the central nervous system. Genetic and environmental factors, bacterial infection, and several other factors are known to be involved in gliomagenesis, although the complete underlying molecular mechanism is not fully understood. Tumorigenesis is a multistep process involving initiation, promotion, and progression. We present a human model of malignant astrocyte transformation established by subjecting primary astrocytes from healthy adults to four sequential cycles of forced anchorage impediment (deadhesion). After limiting dilution of the surviving cells obtained after the fourth deadhesion/readhesion cycle, three clones were randomly selected, and exhibited malignant characteristics, including increased proliferation rate and capacity for colony formation, migration, and anchorage-independent growth in soft agar. Functional assay results for these clonal cells, including response to temozolomide, were comparable to U87MG—a h...
Lysyl oxidase-like 3 (LOXL3), belonging to the lysyl oxidase family, is responsible for the crosslinking in collagen or elastin. The cellular localization of LOXL3 is in the extracellular space by reason of its canonical function. In... more
Lysyl oxidase-like 3 (LOXL3), belonging to the lysyl oxidase family, is responsible for the crosslinking in collagen or elastin. The cellular localization of LOXL3 is in the extracellular space by reason of its canonical function. In tumors, the presence of LOXL3 has been associated with genomic stability, cell proliferation, and metastasis. In silico analysis has shown that glioblastoma was among tumors with the highest LOXL3 expression levels. LOXL3 silencing of U87MG cells by siRNA led to the spreading of the tumor cell surface, and the transcriptome analysis of these cells revealed an upregulation of genes coding for extracellular matrix, cell adhesion, and cytoskeleton components, convergent to an increase in cell adhesion and a decrease in cell invasion observed in functional assays. Significant correlations of LOXL3 expression with genes coding for tubulins were observed in the mesenchymal subtype in the TCGA RNA-seq dataset of glioblastoma (GBM). Conversely, genes involved i...
Arthrogryposis multiplex congenita (AMC) is characterized by congenital contractures and joint deformities, but there are only a few reports of temporomandibular joint (TMJ) involvement. The objective of this investigation was to study... more
Arthrogryposis multiplex congenita (AMC) is characterized by congenital contractures and joint deformities, but there are only a few reports of temporomandibular joint (TMJ) involvement. The objective of this investigation was to study the cause of limited mouth movement in this disease. Four individuals from a family affected by AMC over 5 generations were examined clinically and by magnetic resonance imaging (MRI) and 3-dimensional computerized tomography (3D-CT). The CT scans of the 4 individuals showed hyperplasia of the coronoid process protruding into the infratemporal fossa in 2 of them and cranially to the zygomatic arch in the other 2; the hyperplasia was associated with mechanical limitation of the mouth opening. The MRI showed a disc displacement with reduction in 1 patient and a disc displacement without reduction in another; disc displacement could not be evaluated because of the limited mouth opening in the other 2. The condyle-disc complex of these last 2 individuals could only rotate. The MRI on T2-weighted images showed disc hyposignal in all cases but no alterations in the masticatory muscle tissue. The pedigree of the family suggests an autosomal dominant form of inheritance. The restriction of mouth opening in the 4 individuals affected by AMC was likely due to osseous dysplasia.
Table of final selected genes by microarray analyzes. (XLS 22Â kb)
Gene selection process of involved in MELK pathway. (TIF 3215Â kb)
Table of differentially expressed proteins in U87MG transfected with siRNA for MELK compared with U87MG transfected with non-target control analyzed by proteomics. (XLS 79Â kb)
Expression of final selected genes by microarray analyzes. (TIF 1753Â kb)
Glioblastoma (GBM) is the most aggressive type of brain tumor, with an overall survival of 17 months under the current standard of care therapy. CD99, an over-expressed transmembrane protein in several malignancies, has been considered a... more
Glioblastoma (GBM) is the most aggressive type of brain tumor, with an overall survival of 17 months under the current standard of care therapy. CD99, an over-expressed transmembrane protein in several malignancies, has been considered a potential target for immunotherapy. To further understand this potentiality, we analyzed the differential expression of its two isoforms in human astrocytoma specimens, and the CD99 involved signaling pathways in glioma model U87MG cell line. CD99 was also analyzed in GBM molecular subtypes. Whole transcriptomes by RNA-Seq of CD99-siRNA, and functional in vitro assays in CD99-shRNA, that are found in U87MG cells, were performed. Astrocytoma of different malignant grades and U87MG cells only expressed CD99 isoform 1, which was higher in mesenchymal and classical than in proneural GBM subtypes. Genes related to actin dynamics, predominantly to focal adhesion, and lamellipodia/filopodia formation were down-regulated in the transcriptome analysis, when ...
Review the data published on the subject to create a more comprehensive natural history of intraventricular meningiomas (IVMs). A Medline search up to March 2018 using "intraventricular meningioma" returned 98 papers. As a first... more
Review the data published on the subject to create a more comprehensive natural history of intraventricular meningiomas (IVMs). A Medline search up to March 2018 using "intraventricular meningioma" returned 98 papers. As a first selection step, we adopted the following inclusion criteria: series and case reports about IVMs, as well as papers written in other languages, but abstracts written in English were evaluated. Six hundred eighty-one tumors were evaluated from 98 papers. The majority of the tumors were located in the lateral ventricles (602-88.4%), fourth ventricle (59-8.7%), and third ventricle (20-2.9%). These tumors accounted for a mortality rate of 4.0% (25 deaths) and a recurrence rate of 5.3% (26 recurrences). The majority of the tumors were grade I (89.8%) and consisted of the following subtypes: fibrous, 39.7% (n = 171); transitional, 22.0% (n = 95); meningothelial, 18.6% (n = 80); angiomatosus, 3.2% (n = 14); psammomatous, 2.6% (n = 11); and others, 13.9% (n...
Glioblastoma (GBM) is the most common malignant primary brain tumor affecting adults. In pediatric patients, GBM exhibits genetic variations distinct from those identified in the adult GBM phenotype. This tumor exhibits complex genetic... more
Glioblastoma (GBM) is the most common malignant primary brain tumor affecting adults. In pediatric patients, GBM exhibits genetic variations distinct from those identified in the adult GBM phenotype. This tumor exhibits complex genetic changes leading to malignant progression and resistance to standard therapies including radiotherapy and temozolomide treatment. The GDF15 gene codes for a growth factor whose expression is altered in the presence of inflammations and malignancies. GDF15 is associated with a poor prognosis and with radio- and chemoresistance in a variety of tumors. The aim of this study was to compare the response to GDF15 knockdown in adult (U343) and pediatric (KNS42) GBM cell line models. The expression of the GDF15 gene was investigated by qRT-PCR and overexpression was identified in both GBM cell lines. The KNS42 and U343 cell lines were submitted to lentiviral transduction with shRNA of GDF15 and validated at the protein level. To understand the difference betwe...

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