RESUMEN

Groups (Grp) 3 and 4 are aggressive molecular subgroups of medulloblastoma (MB), with high rates of leptomeningeal dissemination. To date, there is still a paucity of biomarkers for these subtypes of MBs. In this study, we investigated the clinical significance and biological functions of Musashi-1 (MSI1) in Grp3 and Grp4-MBs. First, we assessed the expression profile of MSI1 in 59 primary MB samples (15-WNT, 18-SHH, 9-Grp3, and 17-Grp4 subgroups) by qRT-PCR. MSI1 mRNA expression levels were also validated in an additional public dataset of MBs (GSE85217). The ROC curve was used to validate the diagnostic standards of MSI1 expression. Next, the potential correlated cell-cycle genes were measured by RNA-Seq. Cell cycle, cell viability, and apoptosis were evaluated in a Grp3/Grp4 MB cell line after knockdown of MSI1 and cisplatin treatment. We identified an overexpression of MSI1 with a high accuracy to discriminate Grp3/Grp4-MBs from non-Grp3/Grp4-MBs. We identified that MSI1 knockdown not only triggered transcriptional changes in the cell-cycle pathway, but also affected G2/M phase in vitro, supporting the role of knockdown of MSI1 in cell-cycle arrest. Finally, MSI1 knockdown decreased cell viability and sensitized D283-Med cells to cisplatin treatment by enhancing cell apoptosis. Based on these findings, we suggest that MSI1 modulates cell-cycle progression and may play a role as biomarker for Grp3/Grp4-MBs. In addition, MSI1 knockdown combined with cisplatin may offer a potential strategy to be further explored in Grp3/Grp4-MBs.

RESUMEN

Medulloblastoma is the most common type of pediatric malignant primary brain tumor, and about one-third of patients die due to disease recurrence and most survivors suffer from long-term side effects. MB is clinically, genetically, and epigenetically heterogeneous and subdivided into at least four molecular subgroups: WNT, SHH, Group 3, and Group 4. We evaluated common differentially expressed genes between a Brazilian RNA-seq GSE181293 dataset and microarray GSE85217 dataset cohort of pediatric MB samples using bioinformatics methodology in order to identify hub genes of the molecular subgroups based on PPI network construction, survival and functional analysis. The main finding was the identification of five hub genes from the WNT subgroup that are tumor suppressors, and whose lower expression is related to a worse prognosis for MB patients. Furthermore, the common genes correlated with the five tumor suppressors participate in important pathways and processes for tumor initiation and progression, as well as development and differentiation, and some of them control cell stemness and pluripotency. These genes have not yet been studied within the context of MB, representing new important elements for investigation in the search for therapeutic targets, prognostic markers or for understanding of MB biology.

Asunto(s)

Neoplasias Encefálicas , Neoplasias Cerebelosas , Meduloblastoma , Humanos , Niño , Meduloblastoma/genética , Meduloblastoma/metabolismo , Meduloblastoma/patología , Pronóstico , Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/metabolismo , Neoplasias Cerebelosas/patología , Perfilación de la Expresión Génica , Biomarcadores de Tumor/genética

RESUMEN

Childhood- onset systemic lupus erythematosus (cSLE) is a multisystem inflammatory disease that can lead to severe clinical conditions resulting in early comorbidities. Several genetic, environmental, and immunological factors are known to influence the onset of the disease. MiRNAs have been already considered as potential actors involved in the development and activity of the SLE. Thus, understanding the behavior of these regulators can contribute to clarify the inflammatory process affecting SLE patients. Among miRNAs, miR-125b-5p and miR-9-5p targeting NFKB1 and TRAF6 genes can be involved in the etio-pathogenesis of the disease by modulating inflammation. In this study we evaluated miR-9-5p and miR-125b-5p expression and its target genes NFKB1 and TRAF6 in peripheral blood samples (PBMC) from the 35 cSLE patients and 35 healthy controls. MiRNAs and gene target expression have been evaluated by using RT-PCR with specific TaqMan® probes. Both miR-9-5p [Fold Change (FC) = -2.21; p = 0.002] and miR-125b-5p (FC= -3.30; p < 0.0001) and NFKB1 (FC = -1.84; p < 0.001) were downregulated in cSLE patients, while TRAF6 was upregulated (FC = 1.80; p = 0.006) in cSLE patients when compared to controls. A significant correlation was found between miR-125b-5p and its target gene NFKB1 [Spearman (r) = 0.47; p = 0.023]. Our results showed miR-125b-5p and miR-9-5p differential expression in cSLE patients, possibly contributing to better understanding the role of these regulators in cSLE development and disease pathogenesis.

Asunto(s)

Lupus Eritematoso Sistémico , MicroARNs , Subunidad p50 de NF-kappa B , Factor 6 Asociado a Receptor de TNF , Humanos , Péptidos y Proteínas de Señalización Intracelular , Leucocitos Mononucleares/metabolismo , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Subunidad p50 de NF-kappa B/genética , Subunidad p50 de NF-kappa B/metabolismo , Factor 6 Asociado a Receptor de TNF/genética , Factor 6 Asociado a Receptor de TNF/metabolismo

RESUMEN

The Group 3 Medulloblastoma (Grp3-MB) is an aggressive molecular subtype with a high incidence of metastasis and deaths. In this study, were used an RNA sequencing data (RNA-Seq) from a Brazilian cohort of MBs to identify hub genes associated with the metastatic risk. Data validation were performed by using multiple large datasets from MBs (GSE85217, GSE37418, and EGAS00001001953). DESeq2 package in R software was used to identify the differentially expressed genes (DEGs) in our RNA-Seq data. The DEGs data were accessed to construct the modules/graphs of co-expression and to identify hub genes through Cytoscape platform. The coregulated genes were enriched by the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and the protein-protein interaction (PPI) network was visualized by Cytoscape. The Kaplan-Meier plotter and ROC curves were used to validate the diagnostic and prognostic values of specific biomarkers identified through this model. We identified that inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) as a downregulated hub gene, with a high diagnostic accuracy to Grp3-MBs and associated with tumor metastasis. In addition, we identified genes significantly correlated with ITPR1 that were associated with metastasis in Grp3-MB (ATP1A2, MTTL7A, and RGL1) and worst overall survival in MBs (ANTXR1 and RGL1). Our findings suggest that the ITPR1 hub gene is potentially involved in the metastatic process for Grp3-MB. Our data also provide evidence of targets that may serve as prognostic predictors and/or regulators for the metastatic process that maybe explored for further research of individualized therapy to Grp3-MBs.

Asunto(s)

Neoplasias Cerebelosas , Meduloblastoma , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias Cerebelosas/genética , Biología Computacional , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Inositol , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Meduloblastoma/genética , Proteínas de Microfilamentos/metabolismo , Pronóstico , Receptores de Superficie Celular/genética

RESUMEN

Although ependymoma (EPN) molecular subgroups have been well established by integrated high-throughput platforms, low- and middle-income countries still need low-cost techniques to promptly classify these molecular subtypes. Here, we applied low-cost methods to classify EPNs from a Brazilian cohort with 60 pediatric EPN patients. Fusion transcripts (C11orf95-RELA, YAP1-MAMLD1, and YAP1-FAM118B) were investigated in supratentorial EPN (ST-EPNs) samples through RT-PCR/Sanger sequencing and immunohistochemistry (IHC) for p65/L1CAM. qRT-PCR and IHC were used to evaluate expression profiling of CXorf67, LAMA2, NELL2, and H3K27me3 in posterior fossa EPN (PF-EPNs) samples. In silico analysis was performed using public microarray data to validate the molecular assignment PF-EPNs with LAMA2/NELL2 markers. RELA cases and YAP1-MAMLD1 fusions were identified in nine and four ST-EPNs, respectively. An additional RELA case was identified by IHC. Of note, LAMA2 and NELL2 gene expression and immunoprofiling were less accurate for classifying PF-EPNs, which were confirmed by in silico analysis. Yet, H3K27me3 staining was sufficient to classify PF-EPN subgroups. Our results emphasize the feasibility of a simplified strategy to molecularly classify EPNs in the vast majority of cases (49/60; 81.7%). A coordinated combination of simple methods can be effective to screen pediatric EPN with the available laboratory resources at most low-/mid-income countries, giving support for clinical practice in pediatric EPN. KEY MESSAGES: Low- and middle-income countries need effective low-cost approaches to promptly distinguish between EPN molecular subgroups. RT-PCR plus Sanger sequencing is able to recognize the most common types of RELA and YAP1 fusion transcripts in ST-EPNs. Genetic and protein expressions of LAMA2 and NELL2 are of limited value to accurately stratify PF-EPNs. Immunohistochemical staining for H3K27me3 may be used as a robust method to accurately diagnose PF-EPNs subgroups. A coordinated flow diagram based on these validated low-cost methods is proposed to help clinical-decision making and to reduce costs with NGS assessment outside research protocols.

Asunto(s)

Ependimoma/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Algoritmos , Biomarcadores de Tumor/genética , Brasil , Niño , Biología Computacional/métodos , Manejo de la Enfermedad , Susceptibilidad a Enfermedades , Ependimoma/etiología , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Técnicas de Diagnóstico Molecular/economía , Técnicas de Diagnóstico Molecular/normas , Clasificación del Tumor , Estadificación de Neoplasias , Proteínas de Fusión Oncogénica/genética , Curva ROC , Reproducibilidad de los Resultados , Análisis de Secuencia de ADN

RESUMEN

TP53 p.R337H germline mutation is highly prevalent in the Southern region of Brazil. We sought to investigate TP53 p.R337H mutation in pediatric tumor samples from a population settled in a geographic area of high prevalence for this variant. Mutation assessment and genetic counseling for carriers/relatives were provided. 6/57 tumor samples were heterozygous for TP53 p.R337H. As expected, a high frequency was observed within adrenocortical tumors (3/3) and choroid plexus carcinomas (2/2). Interestingly, the TP53 R337H mutation was found in one case of pediatric rhabdomyosarcoma with Li-Fraumeni pedigree. Our finding expands the spectrum of childhood cancer associated with this germline mutation.

Asunto(s)

Mutación de Línea Germinal , Neoplasias/genética , Proteína p53 Supresora de Tumor/genética , Neoplasias de la Corteza Suprarrenal/epidemiología , Neoplasias de la Corteza Suprarrenal/genética , Brasil/epidemiología , Carcinoma/epidemiología , Carcinoma/genética , Preescolar , Neoplasias del Plexo Coroideo/epidemiología , Neoplasias del Plexo Coroideo/genética , Estudios de Cohortes , Femenino , Humanos , Masculino , Tasa de Mutación , Neoplasias/epidemiología , Mutación Puntual , Rabdomiosarcoma/epidemiología , Rabdomiosarcoma/genética

RESUMEN

We evaluated the potential effects of ATO in different pediatric SHH-MB cell lines (ONS-76: TP53-wild type; DAOY and UW402: TP53-mutated). MB cell lines molecular subgroup was confirmed and TP53 mutations were validated. Cell viability, clonogenicity and apoptosis were evaluated after ATO treatment at different concentrations (1-16 µM) alone or combined with irradiation doses (0.5, 1, 2 and 4 Gy). Rad51 and Ku86 proteins were evaluated by WB. ATO treatment reduced cell viability for all SHH-MB cell lines. Significant decrease of clonogenic capacity and higher apoptosis rates were also observed after ATO exposure, being cell death more pronounced (>70%) for the SHH-MB TP53-mutated. Combined treatment of ATO with irradiation also reduced colonies formation in UW402 tumor cells, which was independent of DNA damage repair proteins Rad51 and Ku86. In silico analyses suggested that a set of genes from cell cycle and p53 pathways are differentially expressed in SHH tumor subtypes, suggesting that cell lines may respond to therapies according to the gene expression profiles. Herein, we showed ATO cytotoxicity in pediatric SHH cell lines, with marked radiosensitizing effect for the MB-SHH TP53-mutated cells. These results highlight the potential of ATO, alone or in combination with radiotherapy, supporting further clinical investigations.

Asunto(s)

Apoptosis/efectos de los fármacos , Trióxido de Arsénico/farmacología , Meduloblastoma/tratamiento farmacológico , Fármacos Sensibilizantes a Radiaciones/farmacología , Línea Celular Tumoral , Niño , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Meduloblastoma/metabolismo , Meduloblastoma/patología , Proteínas de Neoplasias/metabolismo

RESUMEN

Next-generation sequencing platforms are routinely used for molecular assignment due to their high impact for risk stratification and prognosis in medulloblastomas. Yet, low and middle-income countries still lack an accurate cost-effective platform to perform this allocation. TaqMan Low Density array (TLDA) assay was performed using a set of 20 genes in 92 medulloblastoma samples. The same methodology was assessed in silico using microarray data for 763 medulloblastoma samples from the GSE85217 study, which performed MB classification by a robust integrative method (Transcriptional, Methylation and cytogenetic profile). Furthermore, we validated in 11 MBs samples our proposed method by Methylation Array 450 K to assess methylation profile along with 390 MB samples (GSE109381) and copy number variations. TLDA with only 20 genes accurately assigned MB samples into WNT, SHH, Group 3 and Group 4 using Pearson distance with the average-linkage algorithm and showed concordance with molecular assignment provided by Methylation Array 450 k. Similarly, we tested this simplified set of gene signatures in 763 MB samples and we were able to recapitulate molecular assignment with an accuracy of 99.1% (SHH), 94.29% (WNT), 92.36% (Group 3) and 95.40% (Group 4), against 97.31, 97.14, 88.89 and 97.24% (respectively) with the Ward.D2 algorithm. t-SNE analysis revealed a high level of concordance (k = 4) with minor overlapping features between Group 3 and Group 4. Finally, we condensed the number of genes to 6 without significantly losing accuracy in classifying samples into SHH, WNT and non-SHH/non-WNT subgroups. Additionally, we found a relatively high frequency of WNT subgroup in our cohort, which requires further epidemiological studies. TLDA is a rapid, simple and cost-effective assay for classifying MB in low/middle income countries. A simplified method using six genes and restricting the final stratification into SHH, WNT and non-SHH/non-WNT appears to be a very interesting approach for rapid clinical decision-making.

Asunto(s)

Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/patología , Meduloblastoma/genética , Meduloblastoma/patología , Análisis por Matrices de Proteínas/métodos , Adolescente , Niño , Preescolar , Metilación de ADN/fisiología , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Adulto Joven

Asunto(s)

Astrocitoma/genética , Astrocitoma/patología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Metilación de ADN/genética , Exoma/genética , Oftalmopatías/genética , Oftalmopatías/patología , Lipomatosis/genética , Lipomatosis/patología , Síndromes Neurocutáneos/genética , Síndromes Neurocutáneos/patología , Adulto , Niño , Preescolar , Femenino , Duplicación de Gen , Genes ras/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Proteínas de Neoplasias/genética , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , Secuenciación del Exoma

RESUMEN

INTRODUCTION: Medulloblastoma (MB) is an embryonal tumour that originates from genetic deregulation of cerebellar developmental pathways and is classified into 4 molecular subgroups: SHH, WNT, group 3, and group 4. Hydroxymethylation levels progressively increases during cerebellum development suggesting a possibility of deregulation in MB pathogenesis. The aim of this study was to investigate global hydroxymethylation levels and changes in TET and IDH gene expression in MB samples compared to control cerebellum samples. METHODS: The methods utilized were qRT-PCR for gene expression, dot-blot and immunohistochemistry for global hydroxymethylation levels and sequencing for the investigation of IDH mutations. RESULTS: Our results show that global hydroxymethylation level was decreased in MB, and low 5hmC level was associated with the presence of metastasis. TET1 expression levels were decreased in the WNT subgroup, while TET3 expression levels were decreased in the SHH subgroup. Reduced TET3 expression levels were associated with the presence of events such as relapse and death. Higher expression of IDH1 was observed in MB group 3 samples, whereas no mutations were detected in exon 4 of IDH1 and IDH2. CONCLUSION: These findings suggest that reduction of global hydroxymethylation levels, an epigenetic event, may be important for MB development and/or maintenance, representing a possible target in this tumour and indicating a possible interaction of TET and IDH genes with the developmental pathways specifically activated in the MB subgroups. These genes could be specific targets and markers for each subgroup.

Asunto(s)

Neoplasias Cerebelosas/metabolismo , Metilación de ADN , Isocitrato Deshidrogenasa/metabolismo , Meduloblastoma/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias Cerebelosas/genética , Cerebelo/metabolismo , Niño , Preescolar , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Isocitrato Deshidrogenasa/genética , Masculino , Meduloblastoma/genética , Mutación , Proteínas Proto-Oncogénicas/genética

RESUMEN

PURPOSE: Glioblastoma (GBM) is a very aggressive and lethal brain tumor with poor prognosis. Despite new treatment strategies, patients' median survival is still lower than 1 year in most cases. The expression of the BUB gene family has demonstrated to be altered in a variety of solid tumors, pointing to a role as putative therapeutic target. The purpose of this study was to determine BUB1, BUB3, and BUBR1 gene expression profiles in glioblastoma and to analyze the effects of BUB1 and BUBR1 inhibition combined or not with Temozolomide and radiation in the pediatric SF188 GBM cell line. METHODS: For gene expression analysis, 8 cell lines and 18 tumor samples were used. The effect of BUB1 and BUBR1 inhibition was evaluated using siRNA. Apoptosis, cell proliferation, cell cycle kinetics, micronuclei formation, and clonogenic capacity were analyzed after BUB1 and BUBR1 inhibition. Additionally, combinatorial effects of gene inhibition and radiation or Temozolomide (TMZ) treatment were evaluated through proliferation and clonogenic capacity assays. RESULTS: We report the upregulation of BUB1 and BUBR1 expression and the downregulation of BUB3 in GBM samples and cell lines when compared to white matter samples (p < 0.05). Decreased cell proliferation and colony formation after BUB1 and BUBR1 inhibition were observed, along with increased micronuclei formation. Combinations with TMZ also caused cell cycle arrest and increased apoptosis. Moreover, our results demonstrate that BUB1 and BUBR1 inhibition sensitized SF188 cells to γ-irradiation as shown by decreased growth and abrogation of colony formation capacity. CONCLUSION: BUB1 and BUBR1 inhibition decreases proliferation and shows radiosensitizing effects on pediatric GBM cells, which could improve treatment strategies for this devastating tumor. Collectively, these findings highlight the potentials of BUB1 and BUBR1 as putative therapeutic targets for glioblastoma treatment.

Asunto(s)

Neoplasias Encefálicas/genética , Proliferación Celular , Glioblastoma/genética , Proteínas Serina-Treonina Quinasas/genética , Tolerancia a Radiación/genética , Apoptosis/efectos de los fármacos , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica , Glioblastoma/metabolismo , Humanos , Masculino , Proteínas Serina-Treonina Quinasas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcriptoma

RESUMEN

Immune thrombocytopenic purpura (ITP) is a common hematological disorder in the childhood, and it is one of the most common forms of autoimmune disease in pediatric patients. The ITP basis is a primary dysfunction of the immune system. This study aimed to analyze the genetic polymorphisms of the Fcγ receptors IIA and IIIA. The genetic polymorphisms of the Fc receptors γIIA (131H/R) and γRIIIA (158V/F) were analyzed by polymerase chain reaction-restriction fragment length polymorphism technique. Odds ratio and 95% confidence interval were calculated by χ(2) test. Homozygous polymorphic genotype for the FcγRIIIA was significantly more frequent among patients compared with controls (odds ratio = 0.27; 95% confidence interval, 0.09-0.80; P = 0.03). There was no statistical difference between the ITP group and the controls in the analysis of combinations of alleles of the high-affinity Fc receptor, but the ITP individuals with this combination had a lower duration of disease (P = 0.01). Genetic polymorphisms in immune system genes can be important for ITP pathogenesis and disease outcome.

Asunto(s)

Polimorfismo Genético , Púrpura Trombocitopénica Idiopática/genética , Receptores de IgG/genética , Adolescente , Alelos , Niño , Femenino , Genotipo , Humanos , Masculino , Púrpura Trombocitopénica Idiopática/etiología , Estudios Retrospectivos

RESUMEN

BACKGROUND: Glioblastoma remains one of the most devastating human malignancies, and despite therapeutic advances, there are no drugs that significantly improve the patient survival. Altered expression of the Aurora kinases was found in different malignancies, and their inhibition has been studied in cancer therapy. In this study, we analyzed the expression of Aurora A and Aurora B in glioblastoma samples and also analyzed whether the effects of Aurora kinase inhibition were associated with temozolomide or not on cell lines and primary cultures of glioblastoma. MATERIALS AND METHODS: RT-PCR assays were used to determine the mRNA expression in glioblastoma tumor samples and in the cell lines. Cell proliferation was measured by XTT assay, and apoptosis was determined by flow cytometry. Drug combination analyses were made based in Chou-Talalay method. Gamma radiation for clonogenic survival used the doses of 2, 4 and 6 Gy. Changes in Aurora B level were assessed by Western blot analysis. RESULTS: Aurora A and B were expressed in glioblastoma samples as well as in the glioblastoma cell lines (n = 6). Moreover, ZM447439, a selective Aurora kinase inhibitor, decreased the proliferation separately and synergistically with temozolomide in primary cultures and cell lines of glioblastoma. ZM also enhanced the effects of radiation on the two cell lines studied (U343 and U251), mainly when associated with TMZ in U343 cells. Treatment with ZM induced apoptotic cell death and diminished Aurora B protein level. CONCLUSIONS: These data suggest that Aurora kinase inhibition may be a target for glioblastoma treatment and could be used as adjuvant to chemo- and radiotherapy.

Asunto(s)

Antineoplásicos Alquilantes/farmacología , Benzamidas/farmacología , Neoplasias Encefálicas/tratamiento farmacológico , Dacarbazina/análogos & derivados , Glioblastoma/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Quinazolinas/farmacología , Fármacos Sensibilizantes a Radiaciones/farmacología , Apoptosis/efectos de los fármacos , Aurora Quinasa B , Aurora Quinasas , Western Blotting , Neoplasias Encefálicas/enzimología , Línea Celular Tumoral , Proliferación Celular , Dacarbazina/farmacología , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Glioblastoma/enzimología , Humanos , Proteínas Serina-Treonina Quinasas/metabolismo , ARN Neoplásico/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Temozolomida , Factores de Tiempo

RESUMEN

The matrix metalloproteinases (MMP) are endopeptidases performing proteolytic functions in the extracellular matrix and their overexpression has been suggested to be a characteristic of malignant tumors. Molecular changes such as the presence of chimeric protein Ewing's sarcoma protein-friend leukemia virus integration 1 (EWS-FLI1) in the Ewing family of tumors (EFT) and the oncogenes C-ERBB-2, N-MYC, C-MYC in medulloblastoma (MB) promote the overexpression of MMP. In the present study, protein expression of MMP-1, -2, -3, -9 and -14 was qualitatively evaluated in 17 EFT and MB samples of children and adolescent by western blotting and optical densitometry, and the level of gene expression of some MMPs was determined by real-time quantitative polymerase chain reaction. Five MB samples (45.4%) presented expression of the five MMPs and six samples (54.6%) presented expression of at least one of them. Four EFT samples (66.6%) presented expression of MMP-2, -9 and -14, and two samples (33.4%) presented expression of at least one of these MMPs, whereas the presence of MMP-1 and -3 was not observed. Gene analysis showed that MMP-2 had a high expression in MB, while the expression of MMP-9 and MMP-14 was higher in EFT. It has been established that the expression of the MMPs might be related to a complex pathway of gene regulation.

RESUMEN

BACKGROUND: A growing body of evidence has revealed the involvement of epigenetic alterations in the etiology of astrocytomas. In the present study, we aimed to evaluate the association of DNA methylation of histone deacetylase genes (HDAC) with the etiology of astrocytoma, and the implications for epigenetic therapy. MATERIALS AND METHODS: Methylation of the HDAC4, HDAC5 and HDAC6 genes was assessed in 29 tumor samples (astrocytomas grades I, III, and IV) and in the glioblastoma cell lines U87, U251, U343, SF188, and T98G by methylation-specific quantitative PCR (MSED-qPCR). RESULTS: Significantly increased methylation of the HDAC5 gene was observed in astrocytomas when compared to non-neoplastic brain samples (p=0.0007) and to glioblastomas cell lines (p=0.001). A heterogenic methylation pattern was evidenced when compared to the glioblastoma cell lines. Distinct effects on methylation and gene expression were observed after in vitro treatment of the different cell lines with decitabine. CONCLUSION: Our results suggest that abnormal methylation of HDAC genes is involved in the etiology of astrocytomas and indicate that loci-specific epigenetic interindividualities might be associated to the differential responses to treatment with decitabine.

Asunto(s)

Astrocitoma/etiología , Neoplasias Encefálicas/etiología , Metilación de ADN , Histona Desacetilasas/genética , Proteínas Represoras/genética , Adulto , Antimetabolitos Antineoplásicos/farmacología , Astrocitoma/tratamiento farmacológico , Azacitidina/análogos & derivados , Azacitidina/farmacología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Neoplasias Encefálicas/tratamiento farmacológico , Niño , Ensayo de Unidades Formadoras de Colonias , ADN de Neoplasias/genética , Decitabina , Epigénesis Genética , Histona Desacetilasa 6 , Humanos , Reacción en Cadena de la Polimerasa , Células Tumorales Cultivadas

RESUMEN

BACKGROUND: Angiogenesis has been shown as an important process in hematological malignancies. It consists in endothelial proliferation, migration, and tube formation following pro-angiogenic factors releasing, specially the vascular endothelial growth factor (VEGF), which angiogenic effect seems to be dependent on nitric oxide (NO). We examined the association among functional polymorphisms in these two angiogenesis related genes: VEGF (-2578C>A, -1154G>A, and -634G>C) and NOS3 (-786T>C, intron 4 b>a, and Glu298Asp) with prognosis of childhood acute lymphoblastic leukemia (ALL). METHODS: The genotypes were determined and haplotypes estimated in 105 ALL patients that were divided in 2 groups: high risk (HR) and low risk of relapse (LR) patients. In addition, event-free survival curves according to genotypes were assessed. RESULTS: The group HR compared to the LR showed a higher frequency of the alleles -2578C and -634C and the haplotype CGC for VEGF (0.72 vs. 0.51, p<0.008; 0.47 vs. 0.26, p<0.008; and 42.1 vs. 14.5, p<0.006; respectively) and a lower frequency of the haplotype CbGlu (0.4 vs. 8.8,p<0.006), for NOS3. CONCLUSION: Polymorphisms of VEGF and NOS3 genes are associated with high risk of relapse, therefore may have a prognostic impact in childhood ALL.

Asunto(s)

Óxido Nítrico Sintasa de Tipo III/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Factor A de Crecimiento Endotelial Vascular/genética , Secuencia de Bases , Niño , Preescolar , Cartilla de ADN , Supervivencia sin Enfermedad , Femenino , Genotipo , Haplotipos , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Recurrencia , Factores de Riesgo

RESUMEN

The differential diagnosis of renal tumors, particularly in adolescents, may be challenging. We describe an 11-year-old female with a primary intra-renal mass. Initial differential diagnoses included primitive neuroectodermal tumor (PNET), desmoplastic small round cell tumor (DSRCT), and Wilms Tumor (WT). Extensive pathologic and molecular analysis on initial and relapsed tumor samples confirmed WT. The EWS-WT1 and EWS-FLI1 rearrangements, distinctive of DSRCT and PNET were negative. The differential diagnosis on monophasic blastemal WT may be complex. Primary renal DSRCT and PNET have been rarely described. Nevertheless, molecular confirmation for these rare conditions may be necessary in selected cases.

Asunto(s)

Neoplasias Renales/patología , Tumor de Wilms/patología , Adolescente , Niño , Análisis Citogenético , Diagnóstico Diferencial , Femenino , Humanos , Tumores Neuroectodérmicos Periféricos Primitivos/patología , Sarcoma/patología

RESUMEN

This study evaluates the mRNA expression profile of genes TIMP1, TIMP2, MMP2 and MMP9 in diagnostic bone marrow samples from 134 consecutive ALL children by real-time quantitative PCR. A significant association was observed between higher expression levels of MMP9 and low risk group and absence of extramedullary infiltration and higher expression levels of TIMP2 and MMP2 with T-ALL. TIMP1 gene expression values higher than the median were associated with a significantly lower 5-year event free-survival in univariable (P=0.04) and multivariable analysis (P=0.01). Our data address new information in the complex interaction of the migration/adhesion genes and childhood ALL.

Asunto(s)

Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , ARN Mensajero/genética , Inhibidor Tisular de Metaloproteinasa-1/genética , Inhibidor Tisular de Metaloproteinasa-2/genética , Secuencia de Bases , Niño , Preescolar , Cartilla de ADN , Citometría de Flujo , Humanos , Lactante , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Pronóstico

RESUMEN

Polymorphic variations of several genes associated with dietary effects and exposure to environmental carcinogens may influence susceptibility to leukemia development. The objective of the present study was to evaluate the effect of the polymorphisms of debrisoquine hydroxylase (CYP2D6), epoxide hydrolase (EPHX1), myeloperoxidase (MPO), and quinone-oxoreductase (NQO1), which have been implicated in xenobiotic metabolism, on the risk of childhood acute lymphoblastic leukemia (ALL). We evaluated the frequency of polymorphisms in the CYP2D6 (*3 and *4), EPHX1 (*2 and *3), MPO (*2), and NQO1 (*2) genes in 206 patients with childhood ALL and in 364 healthy individuals matched for age and gender from a Brazilian population separated by ethnicity (European ancestry and African ancestry), using the PCR-RFLP method. The CYP2D6 polymorphism variants were associated with an increased risk of ALL. The EPHX1, NQO1, and MPO variant genotypes were significantly associated with a reduced risk of childhood ALL. A significantly stronger protective effect is observed when the EPHX1, NQO1, and MPO variant genotypes are combined suggesting that, CYP2D6 polymorphisms may play a role in the susceptibility to pediatric ALL, whereas the EPHX1, NQO1, and MPO polymorphisms might have a protective function against leukemogenesis.

Asunto(s)

Citocromo P-450 CYP2D6/genética , Epóxido Hidrolasas/genética , Predisposición Genética a la Enfermedad , Factor Estimulante de Colonias de Granulocitos/genética , Interleucina-3/genética , NAD(P)H Deshidrogenasa (Quinona)/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Recombinantes de Fusión/genética , Adolescente , Brasil , Femenino , Humanos , Lactante , Masculino , Proteínas Recombinantes

RESUMEN

Acute lymphoblastic leukemia (ALL) presenting with neutropenia alone is very rare. We describe a newborn with an early life-threatening infection, severe neutropenia and bone marrow findings compatible with severe congenital neutropenia (SCN). She was treated with granulocyte colony-stimulating factor (G-CSF) with complete neutrophil recovery. Three months later she developed a pro-B ALL. We identified a rare loss of 5'-MLL present at the diagnosis of SCN and ALL by FISH analysis using two different MLL (11q23) probes. Molecular analyses for SCN causing mutations (ELA-2, HAX-1 and G6PC3) and for somatic mutations of the CSF3R gene were negative. The early presence of 5'-MLL loss in bone marrow samples may favor the diagnosis of de novo ALL. Nevertheless, the genetic background for SCN is heterogeneous and a non-described mutation for SCN followed by a secondary ALL cannot be excluded. Further genetic investigation may be useful to gain insight into this rare condition in children.

Asunto(s)

Neutropenia/congénito , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Femenino , Humanos , Hibridación Fluorescente in Situ , Recién Nacido , Neutropenia/complicaciones , Neutropenia/tratamiento farmacológico , Reacción en Cadena de la Polimerasa , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico