RESUMO
Adrenocortical carcinoma (ACC) is a rare cancer in which tissue-specific differentiation is paradoxically associated with dismal outcomes. The differentiated ACC subtype CIMP-high is prevalent, incurable, and routinely fatal. CIMP-high ACC possess abnormal DNA methylation and frequent ß-catenin-activating mutations. Here, we demonstrated that ACC differentiation is maintained by a balance between nuclear, tissue-specific ß-catenin-containing complexes, and the epigenome. On chromatin, ß-catenin bound master adrenal transcription factor SF1 and hijacked the adrenocortical super-enhancer landscape to maintain differentiation in CIMP-high ACC; off chromatin, ß-catenin bound histone methyltransferase EZH2. SF1/ß-catenin and EZH2/ß-catenin complexes present in normal adrenals persisted through all phases of ACC evolution. Pharmacologic EZH2 inhibition in CIMP-high ACC expelled SF1/ß-catenin from chromatin and favored EZH2/ß-catenin assembly, erasing differentiation and restraining cancer growth in vitro and in vivo. These studies illustrate how tissue-specific programs shape oncogene selection, surreptitiously encoding targetable therapeutic vulnerabilities. SIGNIFICANCE: Oncogenic ß-catenin can use tissue-specific partners to regulate cellular differentiation programs that can be reversed by epigenetic therapies, identifying epigenetic control of differentiation as a viable target for ß-catenin-driven cancers.
Assuntos
Neoplasias do Córtex Suprarrenal , Carcinoma Adrenocortical , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Carcinoma Adrenocortical/genética , Carcinoma Adrenocortical/metabolismo , Carcinoma Adrenocortical/patologia , Neoplasias do Córtex Suprarrenal/genética , Neoplasias do Córtex Suprarrenal/patologia , Epigênese Genética , Cromatina/genéticaRESUMO
Members of the HDAC family are predictive biomarkers and regulate the tumorigenesis in several cancers. However, the role of these genes in the biology of intracranial ependymomas (EPNs) remains unexplored. Here, an analysis of eighteen HDACs genes in an EPN transcriptomic dataset, revealed significantly higher levels of HDAC4 in supratentorial ZFTA fusion (ST-ZFTA) compared with ST-YAP1 fusion and posterior fossa EPNs, while HDAC7 and SIRT2 were downregulated in ST-ZFTA. HDAC4 was also overexpressed in ST-ZFTA as measured by single-cell RNA-Seq, quantitative real time-polymerase chain reaction, and immunohistochemistry. Survival analyses showed a significantly worse outcome for EPNs with higher HDAC4 and SIRT1 mRNA levels. Ontology enrichment analysis showed an HDAC4-high signature consistent with viral processes while collagen-containing extracellular matrix and cell-cell junction were enriched in those with an HDAC4-low signature. Immune gene analysis demonstrated a correlation between HDAC4 expression and low levels of NK resting cells. Several small molecules compounds targeting HDAC4 and ABCG2, were predicted by in silico analysis to be effective against HDAC4-high ZFTA. Our results provide novel insights into the biology of the HDAC family in intracranial ependymomas and reveal HDAC4 as a prognostic marker and potential therapeutic target in ST-ZFTA.
Assuntos
Neoplasias Encefálicas , Ependimoma , Humanos , Prognóstico , Fatores de Transcrição/genética , Ependimoma/genética , Ependimoma/metabolismo , Neoplasias Encefálicas/genética , Perfilação da Expressão Gênica , Histona Desacetilases/genética , Proteínas Repressoras/genéticaRESUMO
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 human glioblastoma-derived cell lineage-reinforcing malignant cell transformation. RNA-Seq analysis by next-generation sequencing of the transformed clones relative to the primary astrocytes revealed upregulation of genes involved in the PI3K/AKT and Wnt/ß-catenin signaling pathways, in addition to upregulation of genes related to epithelial-mesenchymal transition, and downregulation of genes related to aerobic respiration. These findings, at a molecular level, corroborate the change in cell behavior towards mesenchymal-like cell dedifferentiation. This linear progressive model of malignant human astrocyte transformation is unique in that neither genetic manipulation nor treatment with carcinogens are used, representing a promising tool for testing combined therapeutic strategies for glioblastoma patients, and furthering knowledge of astrocytoma transformation and progression.
Assuntos
Astrócitos , Glioblastoma , Astrócitos/metabolismo , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Transição Epitelial-Mesenquimal , Glioblastoma/patologia , Humanos , Fosfatidilinositol 3-Quinases/metabolismoRESUMO
ATRX-DAXX-H3.3 chromatin remodeler complex is a well known epigenetic factor responsible for the heterochromatin maintenance and control. ATRX is an important nucleosome controller, especially in tandem repeat regions, and DAXX is a multi-function protein with particular role in histone H3.3 deposition due to its chaperone characteristic. Abnormalities in this complex have been associated with telomere dysfunction and consequently with activation of alternative lengthening of telomeres mechanism, genomic instability, and tumor progression in different types of cancer. However, the characterization of this complex is still incomplete in meningioma. We analyzed ATRX, DAXX and H3.3 expressions and the telomere length in a cohort of meningioma of different malignant grades. We observed ATRX upregulation at gene and protein levels in grade II/III meningiomas. A low variability of telomere length was observed in meningiomas across different ages and malignant grades, in contrast to the shortening of telomere length with aging in normal controls.
Assuntos
Proteínas Correpressoras/metabolismo , Histonas/metabolismo , Neoplasias Meníngeas/metabolismo , Meningioma/metabolismo , Chaperonas Moleculares/metabolismo , Telômero/metabolismo , Proteína Nuclear Ligada ao X/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas Correpressoras/genética , Feminino , Histonas/genética , Humanos , Masculino , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/patologia , Meningioma/genética , Meningioma/patologia , Pessoa de Meia-Idade , Chaperonas Moleculares/genética , Telômero/genética , Proteína Nuclear Ligada ao X/genéticaRESUMO
Medulloblastomas (MBs) and glioblastomas (GBMs) are high-incidence central nervous system tumors. Different origin sites and changes in the tissue microenvironment have been associated with the onset and progression. Here, we describe differences between the extracellular matrix (ECM) signatures of these tumors. We compared the proteomic profiles of MB and GBM decellularized tumor samples between each other and their normal decellularized brain site counterparts. Our analysis revealed that 19, 28, and 11 ECM proteins were differentially expressed in MBs, GBMs, and in both MBs and GBMs, respectively. Next, we validated key findings by using a protein tissue array with 53 MB and 55 GBM cases and evaluated the clinical relevance of the identified differentially expressed proteins through their analysis on publicly available datasets, 763 MB samples from the GSE50161 and GSE85217 studies, and 115 GBM samples from RNAseq-TCGA. We report a shift toward a denser fibrillary ECM as well as a clear alteration in the glycoprotein signature, which influences the tumor pathophysiology. MS data have been submitted to the PRIDE repository, project accession: PXD023350.
Assuntos
Neoplasias Encefálicas , Matriz Extracelular , Glioblastoma , Meduloblastoma , Neoplasias Encefálicas/genética , Matriz Extracelular/patologia , Glioblastoma/genética , Humanos , Meduloblastoma/genética , Proteoma/genética , Proteômica , Microambiente TumoralRESUMO
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 in endocytosis and lysosome formation, along with MAPK-binding proteins related to focal adhesion turnover, were downregulated, which may corroborate the observed decrease in cell viability and increase in the rate of cell death. Invasiveness is a major determinant of the recurrence and poor outcome of GBM patients, and downregulation of LOXL3 may contribute to halting the tumor cell invasion.
Assuntos
Aminoácido Oxirredutases/metabolismo , Adesão Celular , Regulação Neoplásica da Expressão Gênica , Glioblastoma/enzimologia , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/fisiologia , Linhagem Celular Tumoral , Proliferação de Células , Simulação por Computador , Citoesqueleto/metabolismo , Endocitose , Matriz Extracelular/metabolismo , Perfilação da Expressão Gênica , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/fisiopatologia , Humanos , Lisossomos/fisiologia , Invasividade NeoplásicaRESUMO
Glioblastoma (GBM) is the most aggressive brain primary malignancy. Toll-like receptor 4 (TLR4) has a dual role in cell fate, promoting cell survival or death depending on the context. Here, we analyzed TLR4 expression in different grades of astrocytoma, and observed increased expression in tumors, mainly in GBM, compared to non-neoplastic brain tissue. TLR4 role was investigated in U87MG, a GBM mesenchymal subtype cell line, upon LPS stimulation. p65 nuclear translocation was observed in late phase, suggesting TLR4-non-canonical pathway activation. In fact, components of ripoptosome and inflammasome cascades were upregulated and they were significantly correlated in GBMs of the TCGA-RNASeq dataset. Moreover, an increased apoptotic rate was observed when the GBM-derived U87MG cells were co-treated with LPS and Temozolomide (TMZ) in comparison to TMZ alone. Increased TLR4 immunostaining was detected in nuclei of U87MG cells 12 h after LPS treatment, concomitant to activation of DNA repair genes. Time-dependent increased RAD51, FEN1 and UNG expression levels were confirmed after LPS stimulation, which may contribute to tumor cell fitness. Moreover, the combined treatment with the RAD51 inhibitor, Amuvatinib in combination with, TMZ after LPS stimulation reduced tumor cell viability more than with each treatment alone. In conclusion, our results suggest that stimulation of TLR4 combined with pharmacological inhibition of the DNA repair pathway may be an alternative treatment for GBM patients.
Assuntos
Neoplasias Encefálicas/metabolismo , Núcleo Celular/metabolismo , Reparo do DNA , DNA de Neoplasias/metabolismo , Glioblastoma/metabolismo , Proteínas de Neoplasias/metabolismo , Transdução de Sinais , Receptor 4 Toll-Like/metabolismo , Fator de Transcrição RelA/metabolismo , Transporte Ativo do Núcleo Celular , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Núcleo Celular/genética , DNA de Neoplasias/genética , Feminino , Glioblastoma/genética , Humanos , Masculino , Proteínas de Neoplasias/genética , Receptor 4 Toll-Like/genética , Fator de Transcrição RelA/genéticaRESUMO
Microglia are specialized macrophages of the central nervous system (CNS) and first to react to pathogens or injury. Over the last decade, transcriptional profiling of microglia significantly contributed to our understanding of their functions. In the case of human CNS samples, either potential CNS pathology in the case of surgery samples, or a postmortem delay (PMD) due to the time needed for tissue access and collection, are potential factors that affect gene expression profiles. To determine the effect of PMD on the microglia transcriptome, we first analyzed mouse microglia, where genotype, antemortem conditions and PMD can be controlled. Microglia were isolated from mice after different PMDs (0, 4, 6, 12, and 24 hr) using fluorescence-activated cell sorting (FACS). The number of viable microglia significantly decreased with increasing PMD, but even after a 12 hr PMD, high-quality RNA could be obtained. PMD had very limited effect on mouse microglia gene expression, only 50 genes were differentially expressed between different PMDs. These genes were related to mitochondrial, ribosomal, and protein binding functions. In human microglia transcriptomes we previously generated, 31 of the 50 PMD-associated mouse genes had human homologs, and their relative expression was also affected by PMD. This study provides a set of genes that shows relative expression changes in relation to PMD, both in mouse and human microglia. Although the gene expression changes detected are subtle, these genes need to be accounted for when analyzing microglia transcriptomes generated from samples with variable PMDs.
Assuntos
Microglia , Transcriptoma , Animais , Autopsia , Sistema Nervoso Central , Perfilação da Expressão Gênica , Humanos , Macrófagos , CamundongosRESUMO
Lysyl oxidase like 3 (LOXL3) is a copper-dependent amine oxidase responsible for the crosslinking of collagen and elastin in the extracellular matrix. LOXL3 belongs to a family including other members: LOX, LOXL1, LOXL2, and LOXL4. Autosomal recessive mutations are rare and described in patients with Stickler syndrome, early-onset myopia and non-syndromic cleft palate. Along with an essential function in embryonic development, multiple biological functions have been attributed to LOXL3 in various pathologies related to amino oxidase activity. Additionally, various novel roles have been described for LOXL3, such as the oxidation of fibronectin in myotendinous junction formation, and of deacetylation and deacetylimination activities of STAT3 to control of inflammatory response. In tumors, three distinct roles were described: (1) LOXL3 interacts with SNAIL and contributes to proliferation and metastasis by inducing epithelial-mesenchymal transition in pancreatic ductal adenocarcinoma cells; (2) LOXL3 is localized predominantly in the nucleus associated with invasion and poor gastric cancer prognosis; (3) LOXL3 interacts with proteins involved in DNA stability and mitosis completion, contributing to melanoma progression and sustained proliferation. Here we review the structure, function and activity of LOXL3 in normal and pathological conditions and discuss the potential of LOXL3 as a therapeutic target in various diseases.
Assuntos
Aminoácido Oxirredutases/genética , Artrite/genética , Fissura Palatina/genética , Doenças do Tecido Conjuntivo/genética , Matriz Extracelular/genética , Perda Auditiva Neurossensorial/genética , Miopia/genética , Neoplasias/genética , Descolamento Retiniano/genética , Aminoácido Oxirredutases/química , Aminoácido Oxirredutases/metabolismo , Artrite/enzimologia , Artrite/patologia , Fissura Palatina/enzimologia , Fissura Palatina/patologia , Colágeno/química , Colágeno/genética , Colágeno/metabolismo , Doenças do Tecido Conjuntivo/enzimologia , Doenças do Tecido Conjuntivo/patologia , Elastina/química , Elastina/genética , Elastina/metabolismo , Transição Epitelial-Mesenquimal/genética , Matriz Extracelular/química , Matriz Extracelular/enzimologia , Regulação da Expressão Gênica , Perda Auditiva Neurossensorial/enzimologia , Perda Auditiva Neurossensorial/patologia , Humanos , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Miopia/enzimologia , Miopia/patologia , Neoplasias/enzimologia , Neoplasias/patologia , Especificidade de Órgãos , Descolamento Retiniano/enzimologia , Descolamento Retiniano/patologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismoRESUMO
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 CD99 was silenced. A decrease in tumor cell migration/invasion, and dysfunction of focal adhesion, were observed in functional assays. In addition, a striking morphological change was detected in CD99-silenced U87MG cells, further corroborating CD99 involvement in actin cytoskeleton rearrangement. Inhibiting the overexpressed CD99 may improve resectability and decrease the recurrence rate of GBM by decreasing tumor cells migration and invasion.
Assuntos
Antígeno 12E7/genética , Antígeno 12E7/metabolismo , Neoplasias Encefálicas/genética , Perfilação da Expressão Gênica/métodos , Glioblastoma/genética , Regulação para Cima , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Quinase 1 de Adesão Focal/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Genes src/genética , Glioblastoma/metabolismo , Humanos , Invasividade Neoplásica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Interferente Pequeno/farmacologia , Análise de Sequência de RNARESUMO
PURPOSE: Adrenocortical carcinoma (ACC) is a rare, aggressive malignancy with few therapies; however, patients with locoregional disease have variable outcomes. The Cancer Genome Atlas project on ACC (ACC-TCGA) identified that cancers of patients with homogeneously rapidly recurrent or fatal disease bear a unique CpG island hypermethylation phenotype, "CIMP-high." We sought to identify a biomarker that faithfully captures this subgroup.Experimental Design: We analyzed ACC-TCGA data to characterize differentially regulated biological processes, and identify a biomarker that is methylated and silenced exclusively in CIMP-high ACC. In an independent cohort of 114 adrenocortical tumors (80 treatment-naive primary ACC, 22 adrenocortical adenomas, and 12 non-naive/nonprimary ACC), we evaluated biomarker methylation by a restriction digest/qPCR-based approach, validated by targeted bisulfite sequencing. We evaluated expression of this biomarker and additional prognostic markers by qPCR. RESULTS: We show that CIMP-high ACC is characterized by upregulation of cell cycle and DNA damage response programs, and identify that hypermethylation and silencing of G0S2 distinguishes this subgroup. We confirmed G0S2 hypermethylation and silencing is exclusive to 40% of ACC, and independently predicts shorter disease-free and overall survival (median 14 and 17 months, respectively). Finally, G0S2 methylation combined with validated molecular markers (BUB1B-PINK1) stratifies ACC into three groups, with uniformly favorable, intermediate, and uniformly dismal outcomes. CONCLUSIONS: G0S2 hypermethylation is a hallmark of rapidly recurrent or fatal ACC, amenable to targeted assessment using routine molecular diagnostics. Assessing G0S2 methylation is straightforward, feasible for clinical decision-making, and will enable the direction of efficacious adjuvant therapies for patients with aggressive ACC.
Assuntos
Neoplasias do Córtex Suprarrenal/genética , Neoplasias do Córtex Suprarrenal/patologia , Carcinoma Adrenocortical/genética , Carcinoma Adrenocortical/patologia , Proteínas de Ciclo Celular/genética , Metilação de DNA , Neoplasias do Córtex Suprarrenal/mortalidade , Carcinoma Adrenocortical/mortalidade , Biomarcadores Tumorais , Linhagem Celular Tumoral , Ilhas de CpG , Mineração de Dados , Feminino , Inativação Gênica , Loci Gênicos , Humanos , Masculino , Gradação de Tumores , Fenótipo , Prognóstico , RecidivaRESUMO
The disruption of mitochondrial activity has been associated with cancer development because it contributes to regulating apoptosis and is the main source of reactive oxygen species (ROS) production. Mitochondrial transcription factor A (TFAM) is a protein that maintains mitochondrial DNA (mtDNA) integrity, and alterations in its expression are associated with mitochondrial damage and cancer development. In addition, studies have shown that mitochondria are a known target of melatonin, the pineal gland hormone that plays an important anti-tumorigenic role. Thus, we hypothesized that melatonin decreases the expression of TFAM (RNA and protein) in the human glioblastoma cell line U87MG, which disrupts mtDNA expression and results in cell death due to increased ROS production and mitochondrial damage. Our results confirm the hypothesis, and also show that melatonin reduced the expression of other mitochondrial transcription factors mRNA (TFB1M and TFB2M) and interfered with mtDNA transcription. Moreover, melatonin delayed cell cycle progression and potentiated the reduction of cell survival due to treatment with the chemotherapeutic agent temozolomide. In conclusion, elucidating the effect of melatonin on TFAM expression should help to understand the signaling pathways involved in glioblastoma progression, and melatonin could be potentially applied in the treatment of this type of brain tumor.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Glioma/patologia , Melatonina/farmacologia , Proteínas Mitocondriais/metabolismo , Terapia de Alvo Molecular , Fatores de Transcrição/metabolismo , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA Mitocondrial/genética , Dacarbazina/análogos & derivados , Dacarbazina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/genética , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Temozolomida , Transcrição Gênica/efeitos dos fármacosRESUMO
PURPOSE: Posterior fossa ependymoma comprises two distinct molecular variants termed EPN_PFA and EPN_PFB that have a distinct biology and natural history. The therapeutic value of cytoreductive surgery and radiation therapy for posterior fossa ependymoma after accounting for molecular subgroup is not known. METHODS: Four independent nonoverlapping retrospective cohorts of posterior fossa ependymomas (n = 820) were profiled using genome-wide methylation arrays. Risk stratification models were designed based on known clinical and newly described molecular biomarkers identified by multivariable Cox proportional hazards analyses. RESULTS: Molecular subgroup is a powerful independent predictor of outcome even when accounting for age or treatment regimen. Incompletely resected EPN_PFA ependymomas have a dismal prognosis, with a 5-year progression-free survival ranging from 26.1% to 56.8% across all four cohorts. Although first-line (adjuvant) radiation is clearly beneficial for completely resected EPN_PFA, a substantial proportion of patients with EPN_PFB can be cured with surgery alone, and patients with relapsed EPN_PFB can often be treated successfully with delayed external-beam irradiation. CONCLUSION: The most impactful biomarker for posterior fossa ependymoma is molecular subgroup affiliation, independent of other demographic or treatment variables. However, both EPN_PFA and EPN_PFB still benefit from increased extent of resection, with the survival rates being particularly poor for subtotally resected EPN_PFA, even with adjuvant radiation therapy. Patients with EPN_PFB who undergo gross total resection are at lower risk for relapse and should be considered for inclusion in a randomized clinical trial of observation alone with radiation reserved for those who experience recurrence.
Assuntos
Procedimentos Cirúrgicos de Citorredução , Ependimoma/terapia , Neoplasias Infratentoriais/terapia , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Terapia Combinada , Ependimoma/mortalidade , Feminino , Humanos , Lactente , Neoplasias Infratentoriais/mortalidade , Masculino , Estudos RetrospectivosRESUMO
Gliomas, the most common primary brain tumors in adults, are classified into four malignancy grades according to morphological features. Recent studies have shown that melatonin treatment induces cytotoxicity in glioma-initiating cells and reduces the invasion and migration of glioma cell lines, inhibiting the nuclear factor κB (NFκB) oncopathway. Given that C6 rat glioma cells produce melatonin, we investigated the correlation between the capacity of gliomas to synthesize/metabolize melatonin and their overall malignancy. We first characterized the melatonergic system of human gliomas cell lines with different grades of aggressiveness (HOG, T98G, and U87MG) and demonstrated that glioma-synthesized melatonin exerts an autocrine antiproliferative effect. Accordingly, the sensitivity to exogenous melatonin was higher for the most aggressive cell line, U87MG, which synthesized/accumulated less melatonin. Using The Cancer Genome Atlas RNAseq data of 351 glioma patients, we designed a predictive model of the content of melatonin in the tumor microenvironment, the ASMT:CYP1B1 index, combining the gene expression levels of melatonin synthesis and metabolism enzymes. The ASMT:CYP1B1 index negatively correlated with tumor grade, as well as with the expression of pro-proliferation and anti-apoptotic NFκB target genes. More importantly, the index was a grade- and histological type-independent prognostic factor. Even when considering only high-grade glioma patients, a low ASMT:CYP1B1 value, which suggests decreased melatonin and enhanced aggressiveness, was strongly associated with poor survival. Overall, our data reveal the prognostic value of the melatonergic system of gliomas and provide insights into the therapeutic role of melatonin.
Assuntos
Acetilserotonina O-Metiltransferasa , Neoplasias Encefálicas , Citocromo P-450 CYP1B1 , Genes Neoplásicos , Glioma , Melatonina , Proteínas de Neoplasias , Acetilserotonina O-Metiltransferasa/genética , Acetilserotonina O-Metiltransferasa/metabolismo , Animais , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Linhagem Celular Tumoral , Citocromo P-450 CYP1B1/genética , Citocromo P-450 CYP1B1/metabolismo , Glioma/diagnóstico , Glioma/genética , Glioma/metabolismo , Glioma/mortalidade , Humanos , Melatonina/biossíntese , Melatonina/genética , NF-kappa B/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Prognóstico , RatosRESUMO
Cell-free DNA shed by cancer cells has been shown to be a rich source of putative tumor-specific biomarkers. Because cell-free DNA from brain and spinal cord tumors cannot usually be detected in the blood, we studied whether the cerebrospinal fluid (CSF) that bathes the CNS is enriched for tumor DNA, here termed CSF-tDNA. We analyzed 35 primary CNS malignancies and found at least one mutation in each tumor using targeted or genome-wide sequencing. Using these patient-specific mutations as biomarkers, we identified detectable levels of CSF-tDNA in 74% [95% confidence interval (95% CI) = 57-88%] of cases. All medulloblastomas, ependymomas, and high-grade gliomas that abutted a CSF space were detectable (100% of 21 cases; 95% CI = 88-100%), whereas no CSF-tDNA was detected in patients whose tumors were not directly adjacent to a CSF reservoir (P < 0.0001, Fisher's exact test). These results suggest that CSF-tDNA could be useful for the management of patients with primary tumors of the brain or spinal cord.
Assuntos
Neoplasias Encefálicas/líquido cefalorraquidiano , DNA de Neoplasias/líquido cefalorraquidiano , Neoplasias da Medula Espinal/líquido cefalorraquidiano , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/genética , Criança , Pré-Escolar , Análise Mutacional de DNA , DNA de Neoplasias/genética , Demografia , Éxons/genética , Feminino , Genoma Humano , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mutação/genética , Neoplasias da Medula Espinal/genéticaRESUMO
Strong evidence implicates intracellular signaling cascades dysfunction in the pathophysiology of Bipolar Disorder (BD). Regulation of AKT/mTOR pathway is a critical signaling pathway in synaptic neurotransmission and plasticity, also modulating cell proliferation and migration. Gene expression of the AKT/mTOR pathway was assessed in 25 BD (DSM-IV-TR criteria) unmedicated depressed individuals at baseline and after 6 weeks of lithium therapy and 31 matched healthy controls. Decreases in blood AKT1 and mTOR mRNA expression, as well as in BAD/BCL-2 expression ratio were observed in short-term BD patients during depressive episodes in comparison to healthy controls. There was no significant change in the expression of AKT1, mTOR, BCL-2, BAD and NDUFA6 after lithium therapy in the total group of BD subjects. However, the changes in AKT1 expression after lithium treatment were positively correlated with depression improvement. An integrated activity within this pathway was observed at both baseline and post-treatment. The present results support an integrated AKT/mTOR signaling pathway activity in a similar fashion to the described in previous human postmortem and rodents brain studies. Overall, the results reinforce a role for AKT1 and mTOR in the pathophysiology of BD and support the relevance of blood mRNA expression as a valid surrogate biological source to study brain intracellular signaling cascades changes and convergent molecular pathways in psychiatric disorders.
Assuntos
Transtorno Bipolar/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Adolescente , Adulto , Antimaníacos/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Redes Reguladoras de Genes/genética , Humanos , Cloreto de Lítio/uso terapêutico , Masculino , Pessoa de Meia-Idade , NADH Desidrogenase/genética , NADH Desidrogenase/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estatísticas não Paramétricas , Adulto Jovem , Proteína de Morte Celular Associada a bcl/genética , Proteína de Morte Celular Associada a bcl/metabolismoRESUMO
OBJECTIVES: The aim of the study was to evaluate the effect of the prior use of corticosteroids (CS) on the presence of inflammatory infiltrates (InI) in muscle biopsies of polymyositis (PM). METHODS: We retrospectively evaluated 60 muscle biopsy samples that had been obtained at the time of the diagnosis of PM. The patients were divided into three groups according to the degree of the InI present in the muscle biopsies: (a) minimal InI present only in an interstitial area of the muscle biopsy (endomysium, perimysium) or in a perivascular area; (B) moderate InI in one or two areas of the interstitium or of the perivascular area; and (C) moderate InI throughout the interstitium or intense inflammation in at least one area of the interstitium or of the perivascular area. RESULTS: The three groups were comparable regarding the demographic, clinical and laboratory features (p>0.05). Approximately half of the patients in each group were using CS at the time of the muscle biopsy. The median (interquartile) duration of CS use [4 (0-38), 4 (0-60) and 5 (0-60) days: groups A, B and C, respectively] and the median cumulative CS dose used [70 (0-1200), 300 (0-1470) and 300 (0-1800)mg] were similar between the groups (p>0.05). CONCLUSIONS: Previous CS use did not influence the presence or the degree of InI found in muscle biopsies in PM with clinical and laboratory disease activity. Our study showed that muscle biopsies should be performed this population, even in individuals who have already been taking CSs.
Assuntos
Corticosteroides/uso terapêutico , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Polimiosite/tratamento farmacológico , Polimiosite/patologia , Adulto , Biópsia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/imunologia , Polimiosite/imunologia , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
OBJECTIVES: To study muscle biopsy tissue from patients with juvenile dermatomyositis (JDM) in order to test the reliability of a score tool designed to quantify the severity of histological abnormalities when applied to biceps humeri in addition to quadriceps femoris. Additionally, to evaluate whether elements of the tool correlate with clinical measures of disease severity. METHODS: 55 patients with JDM with muscle biopsy tissue and clinical data available were included. Biopsy samples (33 quadriceps, 22 biceps) were prepared and stained using standardised protocols. A Latin square design was used by the International Juvenile Dermatomyositis Biopsy Consensus Group to score cases using our previously published score tool. Reliability was assessed by intraclass correlation coefficient (ICC) and scorer agreement (α) by assessing variation in scorers' ratings. Scores from the most reliable tool items correlated with clinical measures of disease activity at the time of biopsy. RESULTS: Inter- and intraobserver agreement was good or high for many tool items, including overall assessment of severity using a Visual Analogue Scale. The tool functioned equally well on biceps and quadriceps samples. A modified tool using the most reliable score items showed good correlation with measures of disease activity. CONCLUSIONS: The JDM biopsy score tool has high inter- and intraobserver agreement and can be used on both biceps and quadriceps muscle tissue. Importantly, the modified tool correlates well with clinical measures of disease activity. We propose that standardised assessment of muscle biopsy tissue should be considered in diagnostic investigation and clinical trials in JDM.
Assuntos
Dermatomiosite/patologia , Músculo Quadríceps/patologia , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Biópsia , Complexo CD3/metabolismo , Criança , Pré-Escolar , Dermatomiosite/metabolismo , Feminino , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Miosinas/metabolismo , Músculo Quadríceps/metabolismo , Reprodutibilidade dos Testes , Índice de Gravidade de DoençaRESUMO
In the present study, we searched for genes highly expressed in placenta and that could contribute to the establishment and maintenance of a malignant phenotype in different types of tumours, and in astrocytomas in particular. We employed a strategy based on the integration of in silico data from previously generated massively parallel signature sequencing and public serial analysis of gene expression databases. Among 12 selected genes, CD99 exhibited the highest relative mRNA expression in GBM compared to non-neoplastic brain tissues. In a larger cohort of astrocytic tumours, we further demonstrated increased CD99 expression in all malignant grades, with GBMs showing the highest values. These findings were confirmed at the protein level by Western blotting and immunohistochemistry. Additionally, we demonstrated the CD99 localisation profile in astrocytic tumours. Interestingly, CD99 expression was confined to the cytoplasm or membrane in more malignant astrocytomas, in contrast to non-neoplastic brain tissue or non-infiltrative pilocytic astrocytoma, which showed no obvious staining in these structures. Comparison of three GBM cell lines revealed higher CD99 expression at the membrane and higher migratory capacity in the A172 and U87MG lines, but lower CD99 expression and no migratory ability in the T98 line. Knocking down CD99 expression by siRNA decreased significantly the migration of both cell lines. These integrated CD99 gene and protein expression results suggest that CD99 expression in astrocytomas of different malignant grades might contribute to the infiltrative ability and support the importance of CD99 as a potential target to reduce infiltrative astrocytoma capacity in migration and invasion.