RESUMO
BACKGROUND: Cognitive impairment is a common and debilitating symptom in patients with diffuse glioma, and is the result of multiple factors. We hypothesized that molecular tumor characteristics influence neurocognitive functioning (NCF), and aimed to identify tumor-related markers of NCF in diffuse glioma patients. METHODS: We examined the relation between cognitive performance (executive function, memory, and psychomotor speed) and intratumoral expression levels of molecular markers in treatment-naive patients with diffuse glioma. We performed a single-center study in a consecutive cohort, through a two-step design: (1) hypothesis-free differential expression and gene set enrichment analysis to identify candidate oncogenetic markers for cognitive impairment. Nineteen molecular markers of interest were derived from this set of genes, as well as from prior knowledge; (2) correlation of cognitive performance to intratumoral expression levels of these nineteen molecular markers, measured with immunohistochemistry. RESULTS: From 708 included patients with immunohistochemical data, we performed an in-depth analysis of neuropsychological data in 197, and differential expression analysis in 65 patients. After correcting for tumor volume and location, we found significant associations between expression levels of CD3 and IDH-1 and psychomotor speed; between IDH-1, ATRX, NLGN3, BDNF, CK2Beta, EAAT1, GAT-3, SRF, and memory performance; and between IDH-1, P-STAT5b, NLGN3, CK2Beta, and executive functioning. P-STAT5b, CD163, CD3, and Semaphorin-3A were independently associated after further correction for histopathological grade. CONCLUSION: Molecular characteristics of glioma can be independent determinants of patients' cognitive functioning. This suggests that besides tumor volume, location, and histological grade, variations in glioma biology influence cognitive performance through mechanisms that include perturbation of neuronal communication. These results pave the way towards targeted cognition improving therapies in neuro-oncology.
Assuntos
Neoplasias Encefálicas , Glioma , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Fator Neurotrófico Derivado do Encéfalo , Glioma/complicações , Glioma/genética , Glioma/patologia , Humanos , Testes Neuropsicológicos , Semaforina-3ARESUMO
Tuberous sclerosis complex (TSC) is a monogenic disorder caused by mutations in either the TSC1 or TSC2 gene, two key regulators of the mechanistic target of the rapamycin complex pathway. Phenotypically, this leads to growth and formation of hamartomas in several organs, including the brain. Subependymal giant cell astrocytomas (SEGAs) are low-grade brain tumors commonly associated with TSC. Recently, gene expression studies provided evidence that the immune system, the MAPK pathway and extracellular matrix organization play an important role in SEGA development. However, the precise mechanisms behind the gene expression changes in SEGA are still largely unknown, providing a potential role for DNA methylation. We investigated the methylation profile of SEGAs using the Illumina Infinium HumanMethylation450 BeadChip (SEGAs n = 42, periventricular control n = 8). The SEGA methylation profile was enriched for the adaptive immune system, T cell activation, leukocyte mediated immunity, extracellular structure organization and the ERK1 & ERK2 cascade. More interestingly, we identified two subgroups in the SEGA methylation data and show that the differentially expressed genes between the two subgroups are related to the MAPK cascade and adaptive immune response. Overall, this study shows that the immune system, the MAPK pathway and extracellular matrix organization are also affected on DNA methylation level, suggesting that therapeutic intervention on DNA level could be useful for these specific pathways in SEGA. Moreover, we identified two subgroups in SEGA that seem to be driven by changes in the adaptive immune response and MAPK pathway and could potentially hold predictive information on target treatment response.
Assuntos
Astrocitoma , Esclerose Tuberosa , Humanos , Astrocitoma/metabolismo , Metilação de DNA/genética , Sirolimo/uso terapêutico , Esclerose Tuberosa/complicações , Esclerose Tuberosa/genética , Esclerose Tuberosa/patologiaRESUMO
AIMS: Tuberous sclerosis complex (TSC) is a genetic disorder associated with dysregulation of the mechanistic target of rapamycin complex 1 (mTORC1) signalling pathway. Neurodevelopmental disorders, frequently present in TSC, are linked to cortical tubers in the brain. We previously reported microRNA-34a (miR-34a) among the most upregulated miRs in tubers. Here, we characterised miR-34a expression in tubers with the focus on the early brain development and assessed the regulation of mTORC1 pathway and corticogenesis by miR-34a. METHODS: We analysed the expression of miR-34a in resected cortical tubers (n = 37) compared with autopsy-derived control tissue (n = 27). The effect of miR-34a overexpression on corticogenesis was assessed in mice at E18. The regulation of the mTORC1 pathway and the expression of the bioinformatically predicted target genes were assessed in primary astrocyte cultures from three patients with TSC and in SH-SY5Y cells following miR-34a transfection. RESULTS: The peak of miR-34a overexpression in tubers was observed during infancy, concomitant with the presence of pathological markers, particularly in giant cells and dysmorphic neurons. miR-34a was also strongly expressed in foetal TSC cortex. Overexpression of miR-34a in mouse embryos decreased the percentage of cells migrated to the cortical plate. The transfection of miR-34a mimic in TSC astrocytes negatively regulated mTORC1 and decreased the expression of the target genes RAS related (RRAS) and NOTCH1. CONCLUSIONS: MicroRNA-34a is most highly overexpressed in tubers during foetal and early postnatal brain development. miR-34a can negatively regulate mTORC1; however, it may also contribute to abnormal corticogenesis in TSC.
Assuntos
Astrócitos/metabolismo , Encéfalo/crescimento & desenvolvimento , MicroRNAs/genética , Esclerose Tuberosa/genética , Adolescente , Adulto , Animais , Encéfalo/patologia , Córtex Cerebral/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Neurônios/patologia , Transdução de Sinais/genética , Esclerose Tuberosa/complicações , Esclerose Tuberosa/patologia , Adulto JovemRESUMO
Tuberous sclerosis complex (TSC) is a monogenetic disease that arises due to mutations in either the TSC1 or TSC2 gene and affects multiple organ systems. One of the hallmark manifestations of TSC are cortical malformations referred to as cortical tubers. These tubers are frequently associated with treatment-resistant epilepsy. Some of these patients are candidates for epilepsy surgery. White matter abnormalities, such as loss of myelin and oligodendroglia, have been described in a small subset of resected tubers but mechanisms underlying this phenomenon are unclear. Herein, we analyzed a variety of neuropathologic and immunohistochemical features in gray and white matter areas of resected cortical tubers from 46 TSC patients using semi-automated quantitative image analysis. We observed divergent amounts of myelin basic protein as well as numbers of oligodendroglia in both gray and white matter when compared with matched controls. Analyses of clinical data indicated that reduced numbers of oligodendroglia were associated with lower numbers on the intelligence quotient scale and that lower amounts of myelin-associated oligodendrocyte basic protein were associated with the presence of autism-spectrum disorder. In conclusion, myelin pathology in cortical tubers extends beyond the white matter and may be linked to cognitive dysfunction in TSC patients.
Assuntos
Córtex Cerebral/patologia , Substância Cinzenta/patologia , Bainha de Mielina/patologia , Esclerose Tuberosa/patologia , Substância Branca/patologia , Feminino , Humanos , Masculino , Oligodendroglia/patologiaRESUMO
Polymicrogyria (PMG) is a developmental cortical malformation characterized by an excess of small and frustrane gyration and abnormal cortical lamination. PMG frequently associates with seizures. The molecular pathomechanisms underlying PMG development are not yet understood. About 40 genes have been associated with PMG, and small copy number variations have also been described in selected patients. We recently provided evidence that epilepsy-associated structural brain lesions can be classified based on genomic DNA methylation patterns. Here, we analyzed 26 PMG patients employing array-based DNA methylation profiling on formalin-fixed paraffin-embedded material. A series of 62 well-characterized non-PMG cortical malformations (focal cortical dysplasia type 2a/b and hemimegalencephaly), temporal lobe epilepsy, and non-epilepsy autopsy controls was used as reference cohort. Unsupervised dimensionality reduction and hierarchical cluster analysis of DNA methylation profiles showed that PMG formed a distinct DNA methylation class. Copy number profiling from DNA methylation data identified a uniform duplication spanning the entire long arm of chromosome 1 in 7 out of 26 PMG patients, which was verified by additional fluorescence in situ hybridization analysis. In respective cases, about 50% of nuclei in the center of the PMG lesion were 1q triploid. No chromosomal imbalance was seen in adjacent, architecturally normal-appearing tissue indicating mosaicism. Clinically, PMG 1q patients presented with a unilateral frontal or hemispheric PMG without hemimegalencephaly, a severe form of intractable epilepsy with seizure onset in the first months of life, and severe developmental delay. Our results show that PMG can be classified among other structural brain lesions according to their DNA methylation profile. One subset of PMG with distinct clinical features exhibits a duplication of chromosomal arm 1q.
Assuntos
Encéfalo/patologia , Cromossomos/metabolismo , Epilepsia Resistente a Medicamentos/patologia , Malformações do Desenvolvimento Cortical/patologia , Polimicrogiria/patologia , Variações do Número de Cópias de DNA/fisiologia , Epilepsia Resistente a Medicamentos/complicações , Epilepsia Resistente a Medicamentos/genética , Feminino , Humanos , Masculino , Polimicrogiria/complicações , Polimicrogiria/genética , Convulsões/patologiaRESUMO
Tuberous sclerosis complex (TSC), a rare genetic disorder caused by a mutation in the TSC1 or TSC2 gene, is characterized by the growth of hamartomas in several organs. This includes the growth of low-grade brain tumors, known as subependymal giant cell astrocytomas (SEGA). Previous studies have shown differential expression of genes related to the extracellular matrix in SEGA. Matrix metalloproteinases (MMPs), and their tissue inhibitors (TIMPs) are responsible for remodeling the extracellular matrix and are associated with tumorigenesis. This study aimed to investigate the MMP/TIMP proteolytic system in SEGA and the regulation of MMPs by microRNAs, which are important post-transcriptional regulators of gene expression. We investigated the expression of MMPs and TIMPs using previously produced RNA-Sequencing data, real-time quantitative PCR and immunohistochemistry in TSC-SEGA samples and controls. We found altered expression of several MMPs and TIMPs in SEGA compared to controls. We identified the lowly expressed miR-320d in SEGA as a potential regulator of MMPs, which can decrease MMP2 expression in human fetal astrocyte cultures. This study provides evidence of a dysregulated MMP/TIMP proteolytic system in SEGA of which MMP2 could be rescued by microRNA-320d. Therefore, further elucidating microRNA-mediated MMP regulation may provide insights into SEGA pathogenesis and identify novel therapeutic targets.
Assuntos
Astrocitoma/metabolismo , Metaloproteinases da Matriz/metabolismo , MicroRNAs/biossíntese , Proteólise , Inibidores Teciduais de Metaloproteinases/metabolismo , Esclerose Tuberosa/metabolismo , Adolescente , Adulto , Astrocitoma/genética , Astrocitoma/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Metaloproteinases da Matriz/genética , MicroRNAs/genética , Inibidores Teciduais de Metaloproteinases/genética , Esclerose Tuberosa/genética , Esclerose Tuberosa/patologia , Adulto JovemRESUMO
Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited neurocutaneous disorder caused by inactivating mutations in TSC1 or TSC2, key regulators of the mechanistic target of rapamycin complex 1 (mTORC1) pathway. In the CNS, TSC is characterized by cortical tubers, subependymal nodules and subependymal giant cell astrocytomas (SEGAs). SEGAs may lead to impaired circulation of CSF resulting in hydrocephalus and raised intracranial pressure in patients with TSC. Currently, surgical resection and mTORC1 inhibitors are the recommended treatment options for patients with SEGA. In the present study, high-throughput RNA-sequencing (SEGAs n = 19, periventricular control n = 8) was used in combination with computational approaches to unravel the complexity of SEGA development. We identified 9400 mRNAs and 94 microRNAs differentially expressed in SEGAs compared to control tissue. The SEGA transcriptome profile was enriched for the mitogen-activated protein kinase (MAPK) pathway, a major regulator of cell proliferation and survival. Analysis at the protein level confirmed that extracellular signal-regulated kinase (ERK) is activated in SEGAs. Subsequently, the inhibition of ERK independently of mTORC1 blockade decreased efficiently the proliferation of primary patient-derived SEGA cultures. Furthermore, we found that LAMTOR1, LAMTOR2, LAMTOR3, LAMTOR4 and LAMTOR5 were overexpressed at both gene and protein levels in SEGA compared to control tissue. Taken together LAMTOR1-5 can form a complex, known as the 'Ragulator' complex, which is known to activate both mTORC1 and MAPK/ERK pathways. Overall, this study shows that the MAPK/ERK pathway could be used as a target for treatment independent of, or in combination with mTORC1 inhibitors for TSC patients. Moreover, our study provides initial evidence of a possible link between the constitutive activated mTORC1 pathway and a secondary driver pathway of tumour growth.
Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , MAP Quinases Reguladas por Sinal Extracelular/genética , Sistema de Sinalização das MAP Quinases/genética , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Esclerose Tuberosa/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adolescente , Adulto , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Astrocitoma/etiologia , Astrocitoma/metabolismo , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/metabolismo , Butadienos/farmacologia , Criança , Pré-Escolar , Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Perfilação da Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Nitrilas/farmacologia , RNA-Seq , Análise de Sequência de RNA , Esclerose Tuberosa/complicações , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Células Tumorais Cultivadas , Adulto JovemRESUMO
Recent studies suggested a possible association between malformations of cortical development and microvascular density. In this study we aimed to further elucidate the relation between microvascular density and cortical developmental abnormalities in a cohort of 97 patients with epilepsy and histologically proven mild malformation of cortical development (mMCD), focal cortical dysplasia (FCD) or tuberous sclerosis complex (TSC). Surgical tissue samples were analyzed with quantitative measures of vessel density, T-cell response, microglial activation and myelin content. Subsequently, the results were compared to an age- and localization matched control group. We observed an increase in microvasculature in white matter of TSC cortical tubers, which is linked to inflammatory response. No increase was seen in mMCD or FCD subtypes compared to controls. In mMCD/FCD and tubers, lesional cortex and white matter showed increased vascular density compared to perilesional tissues. Moreover, cortical vessel density increased with longer epilepsy duration and older age at surgery while in controls it decreased with age. Our findings suggest for that the increase in white matter vascular density might be pathology-specific rather than a consequence of ongoing epileptic activity. Increased cortical vessel density with age and with longer epilepsy duration in mMCD/FCD's and tubers, however, could be a consequence of seizures.
Assuntos
Córtex Cerebral/patologia , Epilepsia/patologia , Malformações do Desenvolvimento Cortical do Grupo I/patologia , Malformações do Desenvolvimento Cortical/patologia , Microvasos/patologia , Esclerose Tuberosa/patologia , Adolescente , Adulto , Córtex Cerebral/cirurgia , Criança , Pré-Escolar , Epilepsia/cirurgia , Feminino , Humanos , Lactente , Masculino , Malformações do Desenvolvimento Cortical/cirurgia , Malformações do Desenvolvimento Cortical do Grupo I/cirurgia , Pessoa de Meia-Idade , Esclerose Tuberosa/cirurgia , Adulto JovemRESUMO
INTRODUCTION: The subventricular zone (SVZ) in the brain is associated with gliomagenesis and resistance to treatment in glioblastoma. In this study, we investigate the prognostic role and biological characteristics of subventricular zone (SVZ) involvement in glioblastoma. METHODS: We analyzed T1-weighted, gadolinium-enhanced MR images of a retrospective cohort of 647 primary glioblastoma patients diagnosed between 2005-2013, and performed a multivariable Cox regression analysis to adjust the prognostic effect of SVZ involvement for clinical patient- and tumor-related factors. Protein expression patterns of a.o. markers of neural stem cellness (CD133 and GFAP-δ) and (epithelial-) mesenchymal transition (NF-κB, C/EBP-ß and STAT3) were determined with immunohistochemistry on tissue microarrays containing 220 of the tumors. Molecular classification and mRNA expression-based gene set enrichment analyses, miRNA expression and SNP copy number analyses were performed on fresh frozen tissue obtained from 76 tumors. Confirmatory analyses were performed on glioblastoma TCGA/TCIA data. RESULTS: Involvement of the SVZ was a significant adverse prognostic factor in glioblastoma, independent of age, KPS, surgery type and postoperative treatment. Tumor volume and postoperative complications did not explain this prognostic effect. SVZ contact was associated with increased nuclear expression of the (epithelial-) mesenchymal transition markers C/EBP-ß and phospho-STAT3. SVZ contact was not associated with molecular subtype, distinct gene expression patterns, or markers of stem cellness. Our main findings were confirmed in a cohort of 229 TCGA/TCIA glioblastomas. CONCLUSION: In conclusion, involvement of the SVZ is an independent prognostic factor in glioblastoma, and associates with increased expression of key markers of (epithelial-) mesenchymal transformation, but does not correlate with stem cellness, molecular subtype, or specific (mi)RNA expression patterns.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Proteína beta Intensificadora de Ligação a CCAAT/genética , Glioblastoma/genética , Ventrículos Laterais/metabolismo , Fator de Transcrição STAT3/genética , Antígeno AC133/genética , Antígeno AC133/metabolismo , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/cirurgia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Variações do Número de Cópias de DNA , Transição Epitelial-Mesenquimal , Feminino , Expressão Gênica , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Glioblastoma/diagnóstico por imagem , Glioblastoma/mortalidade , Glioblastoma/cirurgia , Humanos , Ventrículos Laterais/diagnóstico por imagem , Ventrículos Laterais/patologia , Ventrículos Laterais/cirurgia , Imageamento por Ressonância Magnética , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , NF-kappa B/genética , NF-kappa B/metabolismo , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Polimorfismo de Nucleotídeo Único , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fator de Transcrição STAT3/metabolismo , Carga TumoralRESUMO
Low-level somatic mutations have been shown to be the major genetic etiology of intractable epilepsy. The extents thereof, however, have yet to be systematically and accurately explored in a large cohort of resected epilepsy brain tissues. Moreover, clinically useful and precise analysis tools for detecting low-level somatic mutations from unmatched formalin-fixed paraffin-embedded (FFPE) brain samples, the most clinically relevant samples, are still lacking. In total, 446 tissues samples from 232 intractable epilepsy patients with various brain pathologies were analyzed using deep sequencing (average read depth, 1112x) of known epilepsy-related genes (up to 28 genes) followed by confirmatory site-specific amplicon sequencing. Pathogenic mutations were discovered in 31.9% (74 of 232) of the resected epilepsy brain tissues and were recurrently found in only eight major focal epilepsy genes, including AKT3, DEPDC5, MTOR, PIK3CA, TSC1, TSC2, SCL35A2, and BRAF. Somatic mutations, two-hit mutations, and germline mutations accounted for 22.0% (51), 0.9% (2), and 9.1% (21) of the patients with intractable epilepsy, respectively. The majority of pathogenic somatic mutations (62.3%, 33 of 53) had a low variant allelic frequency of less than 5%. The use of deep sequencing replicates in the eight major focal epilepsy genes robustly increased PPVs to 50-100% and sensitivities to 71-100%. In an independent FCDII cohort of only unmatched FFPE brain tissues, deep sequencing replicates in the eight major focal epilepsy genes identified pathogenic somatic mutations in 33.3% (5 of 15) of FCDII individuals (similar to the genetic detecting rate in the entire FCDII cohort) without any false-positive calls. Deep sequencing replicates of major focal epilepsy genes in unmatched FFPE brain tissues can be used to accurately and efficiently detect low-level somatic mutations, thereby improving overall patient care by enriching genetic counseling and informing treatment decisions.
Assuntos
Encéfalo , Epilepsia Resistente a Medicamentos/genética , Mutação , Análise de Sequência/métodos , Adolescente , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/cirurgia , Criança , Pré-Escolar , Estudos de Coortes , Epilepsia Resistente a Medicamentos/metabolismo , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/cirurgia , Feminino , Humanos , Lactente , Masculino , Adulto JovemRESUMO
Intracranial aneurysms (IAs) develop more often on bifurcations compared with the rest of the circle of Willis (CoW). We investigated histological differences between 2 high IA prevalence sites (anterior communicating artery [AcomA] and basilar tip) and 2 corresponding low IA prevalence sites (anterior cerebral artery [ACA] and basilar artery [BA]) using histological sections of 10 CoWs without IAs. Medial defect density in the AcomA was 0.24 medial defects/mm compared with 0.02 for the A1 part and 0.03 for the A2 part of the ACA. In the basilar tip we found 0.15 medial defects/mm compared with 0.14 in the BA. Vascular smooth muscle cells (VSMCs) were more often disorganized in both high-prevalence sites (AcomA: 10/10, basilar tip: 5/10) compared with low-prevalence sites (both ACA and BA: 1/10). Intima thickening was more severe in the high-prevalence sites. Vascular wall thickness was not significantly different between high- and low-prevalence sites, but had a larger variance in high- compared with low-prevalence sites (AcomA vs ACA: p = 6.8E-12, basilar tip vs BA: p = 0.02). Disorganized VSMCs at high-prevalence sites likely result in a higher susceptibility to hemodynamic stress, leading to more vascular remodeling (such as intima thickening), which could increase the likelihood of IA formation.
Assuntos
Vasos Sanguíneos/patologia , Aneurisma Intracraniano/patologia , Artéria Cerebral Anterior/patologia , Artéria Basilar/patologia , Feminino , Hemodinâmica , Humanos , Aneurisma Intracraniano/epidemiologia , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/patologia , Prevalência , Túnica Íntima/patologiaRESUMO
Mild malformation of cortical development (mMCD) and focal cortical dysplasia (FCD) subtypes combined are by far the most common histological diagnoses in children who undergo surgery as treatment for refractory epilepsy. In patients with refractory epilepsy, a substantial burden of disease is due to cognitive impairment. We studied intelligence quotient (IQ) or developmental quotient (DQ) values and their change after epilepsy surgery in a consecutive series of 42 children (median age at surgery: 4.5, range: 0-17.0â¯years) with refractory epilepsy due to mMCD/FCD. Cognitive impairment, defined as IQ/DQ below 70, was present in 51% prior to surgery. Cognitive impairment was associated with earlier onset of epilepsy, longer epilepsy duration, and FCD type I histology. Clinically relevant improvement of ≥10 IQ/DQ points was found in 24% of children and was related to the presence of presurgical epileptic encephalopathy (EE). At time of postsurgical cognitive testing, 59% of children were completely seizure-free (Engel 1A). We found no association between cognitive outcome and seizure or medication status at two years of follow-up. Epilepsy surgery in children with mMCD or FCD not only is likely to result in complete and continuous seizure freedom, but also improves cognitive function in many.
Assuntos
Disfunção Cognitiva/cirurgia , Epilepsia/cirurgia , Malformações do Desenvolvimento Cortical/cirurgia , Avaliação de Resultados em Cuidados de Saúde , Adolescente , Criança , Pré-Escolar , Disfunção Cognitiva/etiologia , Anormalidades Craniofaciais/complicações , Anormalidades Craniofaciais/cirurgia , Epilepsia Resistente a Medicamentos/complicações , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsias Parciais/complicações , Epilepsias Parciais/cirurgia , Epilepsia/complicações , Feminino , Seguimentos , Humanos , Lactente , Masculino , Malformações do Desenvolvimento Cortical/complicaçõesRESUMO
Focal cortical dysplasia (FCD) and mild malformation of cortical development (mMCD) are frequent histopathologic diagnoses in patients who undergo surgery for refractory epilepsy. Literature concerning surgical outcome in patients with mMCD, as well as its contrast with FCD, has been scarce. We studied 88 patients with a histopathologic diagnosis of isolated FCD (n = 57) or mMCD (n = 31), revised according to the latest International League Against Epilepsy (ILAE) guidelines, who underwent resective or disconnective surgery. Our findings suggest differences between mMCD and FCD in clinical presentation and surgical outcome after surgery. Patients with mMCD developed seizures later in life, and their lesions had a predilection for location in the temporal lobe and remained undetected by magnetic resonance imaging (MRI) more frequently. A diagnosis of mMCD has a less favorable surgical outcome. Still, 32% of these patients reached continuous seizure freedom (Engel class 1A) at a latest median follow-up duration of 8 years, compared to 59% in FCD. A histopathologic diagnosis of mMCD, extratemporal surgery, and indication of an incomplete resection each were independent predictors of poor outcome.
RESUMO
Epilepsy at presentation is an independent favorable prognostic factor in glioblastoma (GBM). In this study, we analyze the oncologic signaling pathways that associate with epilepsy in human GBMs, and that can underlie this prognostic effect. Following ethical approval and patient consent, fresh frozen GBM tissue was obtained from 76 patient surgeries. Hospital records were screened for the presence of seizures at presentation of the disease. mRNA and miRNA expression-based and gene set enrichment analyses were performed on these tissues, to uncover candidate oncologic pathways that associate with epilepsy. We performed qPCR experiments and immunohistochemistry on tissue microarrays containing 286 GBMs to further explore the association of these candidate pathways and of markers of mesenchymal transformation (NF-κB, CEBP-ß, STAT3, STAT5b, VEGFA, SRF) with epilepsy. Gene sets involved in hypoxia/HIF-1α, STAT5, CEBP-ß and epithelial-mesenchymal transformation signaling were significantly downregulated in epileptogenic GBMs. On confirmatory protein expression analyses, epileptogenic tumors were characterized by a significant downregulation of phospho-STAT5b, a target of HIF-1α. Epilepsy status did not associate with molecular subclassification or miRNA expression patterns of the tumors. Epileptogenic GBMs correlate with decreased hypoxia/ HIF-1α/STAT5b signaling compared to glioblastomas that do not present with epilepsy.
RESUMO
BACKGROUND: The antiepileptic drug valproic acid (VPA) inhibits histone deacetylase in glioblastoma cells in vitro, which influences several oncogenic pathways and decreases glioma cell proliferation. The clinical relevance of these observations remains unclear, as VPA does not seem to affect glioblastoma patient survival. In this study, we analyzed whether the in vitro effects of VPA treatment on histone acetylation are also observed in tumor tissues of glioblastoma patients. METHODS: The in vitro effects of VPA treatment on histone acetylation were assessed with immunofluorescence and western blotting. On tissue microarrays and in fresh-frozen glioblastoma tissues we investigated the histone acetylation patterns of patients who were either treated with VPA or did not receive antiepileptic drugs at the time of their surgery. We also performed mRNA expression-based and gene set enrichment analyses on these tissues. RESULTS: VPA increased the expression levels of acetylated histones H3 and H4 in vitro, in agreement with previous reports. In tumor samples obtained from glioblastoma patients, however, VPA treatment affected neither gene (set) expression nor histone acetylation. CONCLUSIONS: The in vitro effects of VPA on histone acetylation status in glioblastoma cells could not be confirmed in clinical tumor samples of glioblastoma patients using antiepileptic doses of VPA, which reflects the lack of effect of VPA on the clinical outcome of glioblastoma patients.
RESUMO
Glioneuronal tumours, including gangliogliomas and dysembryoplastic neuroepithelial tumours, represent the most common low-grade epilepsy-associated brain tumours and are a well-recognized cause of intractable focal epilepsy in children and young adults. Classification is predominantly based on histological features, which is difficult due to the broad histological spectrum of these tumours. The aim of the present study was to find molecular markers that can be used to identify entities within the histopathology spectrum of glioneuronal tumours. The focus of this study was on microRNAs (miRNAs). miRNAs are important post-transcriptional regulators of gene expression and are involved in the pathogenesis of different neurological diseases and oncogenesis. Using a miRNA array, miR-519d and miR-4758 were found to be upregulated in gangliogliomas (n=26) compared to control cortex (n=17), peritumoural tissue (n=7), dysembryoplastic neuroepithelial tumours (n=9) and astrocytomas (grade I-IV; subependymal giant cell astrocytomas, n=10; pilocytic astrocytoma, n=15; diffuse astrocytoma grade II, n=10; grade III, n=14 and glioblastoma n=15). Furthermore, the PI3K/AKT3/P21 pathway, which is predicated to be targeted by miR-519d and miR-4758, was deregulated in gangliogliomas. Functionally, overexpression of miR-519d in an astrocytic cell line resulted in a downregulation of CDKN1A (P21) and an increase in cell proliferation, whereas co-transfection with miR-4758 counteracted this effect. These results suggest that miR-519d and miR-4758 might work in concert as regulators of the cell cycle in low grade gliomas. Furthermore, these miRNAs could be used to distinguish gangliogliomas from dysembryoplastic neuroepithelial tumours and other low and high grade gliomas and may lead to more targeted therapy.
RESUMO
In this article, we report data on vessel wall thickness parameters derived from different arterial segments of the circle of Willis and its primary branches in patients with and without cerebrovascular disease. Also data on inter-rater reliability and agreement of the derived vessel wall parameters are reported. For further interpretation and discussion please refer to the research article "ex vivo vessel wall thickness measurements of the human circle of Willis using 7T MRI" (Harteveld et al., in press) [1].
RESUMO
BACKGROUND AND AIMS: MRI can detect intracranial vessel wall thickening before any luminal stenosis is present. Apart from representing a vessel wall lesion, wall thickening could also reflect normal (age-related) variations in vessel wall thickness present throughout the intracranial arterial vasculature. The aim of this study was to perform vessel wall thickness measurements of the major intracranial arteries in ex vivo circle of Willis (CoW) specimens using 7T MRI, to obtain more detailed information about wall thickness variations of the intracranial arteries. METHODS: Fifteen human CoW specimens were scanned at 7T MRI with an ultrahigh-resolution T1-weighted sequence. Five specimens were used for validation of MRI measurements with histology and evaluation of inter-rater reliability and agreement. The other 10 specimens from patients with (nâ¯=â¯5) and without (nâ¯=â¯5) cerebrovascular disease were used for vessel wall thickness measurements over the entire length of the major arterial segments of the CoW using MRI only. RESULTS: MRI measurements showed excellent agreement with histology. Mean wall thickness varied from 0.45 to 0.66â¯mm, minimum wall thickness from 0.31 to 0.42â¯mm, maximum wall thickness from 0.52 to 0.86â¯mm, and normalized wall index from 0.64 to 0.75. On average, vessel walls were thicker for symptomatic patients compared to asymptomatic patients. CONCLUSIONS: High-resolution MRI enables accurate measurement of vessel wall thickness in ex vivo CoW specimens. Vessel wall thickness measurements over the entire length of segments showed considerable variation both within and between arterial segments of patients.
Assuntos
Círculo Arterial do Cérebro/anatomia & histologia , Círculo Arterial do Cérebro/diagnóstico por imagem , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias Cerebrais/anatomia & histologia , Artérias Cerebrais/diagnóstico por imagem , Feminino , Humanos , Técnicas In Vitro , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Estudos RetrospectivosRESUMO
Pediatric medulloblastomas are the most frequently diagnosed embryonal tumors of the central nervous system. Current therapies cause severe neurological and cognitive side effects including secondary malignancies. Cellular immunotherapy might be key to improve survival and to avoid morbidity. Efficient killing of tumor cells using immunotherapy requires to overcome cancer-associated strategies to evade cytotoxic immune responses. Here, we examined the immune response and immune evasion strategies in pediatric medulloblastomas. Cytotoxic T-cells, infiltrating medulloblastomas with variable activation status, showed no correlation with overall survival of the patients. We found limited numbers of PD1+ T-cells and complete absence of PD-L1 on medulloblastomas. Medulloblastomas downregulated immune recognition molecules MHC-I and CD1 d. Intriguingly, expression of granzyme inhibitors SERPINB1 and SERPINB4 was acquired in 23% and 50% of the tumors, respectively. Concluding, pediatric medulloblastomas exploit multiple immune evasion strategies to overcome immune surveillance. Absence of PD-L1 expression in medulloblastoma suggest limited or no added value for immunotherapy with PD1/PD-L1 blockers.
RESUMO
BACKGROUND: We aimed to gain new insights into the pathogenesis of sporadic ALS (sALS) through a comprehensive proteomic analysis. METHODS: Protein profiles of the anterior and posterior horn in post-mortem spinal cord samples of 10 ALS patients and 10 controls were analysed using 2D-differential gel electrophoresis. The identified protein spots with statistically significant level changes and a spot ratio >2.0 were analysed by LC-MS/MS. RESULTS: In the posterior horn only 3 proteins were differentially expressed. In the anterior horn, 16 proteins with increased levels and 2 proteins with decreased levels were identified in ALS compared to controls. The identified proteins were involved in mitochondrial metabolism, calcium homeostasis, protein metabolism, glutathione homeostasis, protein transport and snRNP assembly. The two proteins with decreased levels, ATP5D and calmodulin, were validated by Western blot and immunostaining. Immunohistochemical and immunofluorescent double staining of ATP5D and synaptophysin showed that the reduction of ATP5D was most pronounced at synapses. CONCLUSIONS: We speculate that mitochondrial dysfunction in synaptic clefts could play an important role in sALS pathogenesis. A similar approach revealed decreased calmodulin expression mainly in the neuronal body and dendrites of ALS patients. These findings contribute to a deeper understanding of the disease process underlying ALS.