NBIA (neurodegeneration with brain iron accumulation) comprises a heterogeneous group of neurodegenerative diseases having as a common denominator, iron overload in specific brain areas, mainly basal ...ganglia and globus pallidus. In the past decade a bunch of disease genes have been identified, but NBIA pathomechanisms are still not completely clear. PKAN (pantothenate kinase-associated neurodegeneration), an autosomal recessive disorder with progressive impairment of movement, vision and cognition, is the most common form of NBIA. It is caused by mutations in the PANK2 (pantothenate kinase 2) gene, coding for a mitochondrial enzyme that phosphorylates vitamin B5 in the first reaction of the CoA (coenzyme A) biosynthetic pathway. A distinct form of NBIA, denominated CoPAN (CoA synthase protein-associated neurodegeneration), is caused by mutations in the CoASY (CoA synthase) gene coding for a bifunctional mitochondrial enzyme, which catalyses the final steps of CoA biosynthesis. These two inborn errors of CoA metabolism further support the concept that dysfunctions in CoA synthesis may play a crucial role in the pathogenesis of NBIA.
Neurodegeneration with brain iron accumulation (NBIA) comprises a clinically and genetically heterogeneous group of disorders with progressive extrapyramidal signs and neurological deterioration, ...characterized by iron accumulation in the basal ganglia. Exome sequencing revealed the presence of recessive missense mutations in COASY, encoding coenzyme A (CoA) synthase in one NBIA-affected subject. A second unrelated individual carrying mutations in COASY was identified by Sanger sequence analysis. CoA synthase is a bifunctional enzyme catalyzing the final steps of CoA biosynthesis by coupling phosphopantetheine with ATP to form dephospho-CoA and its subsequent phosphorylation to generate CoA. We demonstrate alterations in RNA and protein expression levels of CoA synthase, as well as CoA amount, in fibroblasts derived from the two clinical cases and in yeast. This is the second inborn error of coenzyme A biosynthesis to be implicated in NBIA.
Purpose: Recent data suggest that methylation of the DNA repair gene O 6 -methylguanine DNA methyltransferase (MGMT), by increasing the chemosensitivity of glioblastoma multiforme, is significantly
...associated with improved prognosis. Results in contradiction with these findings, however, are present in the literature and
the clinical and genetic context framing MGMT methylation is poorly characterized.
Experimental Design: To address these issues, we have investigated the MGMT methylation status, clinical and magnetic resonance imaging characteristics,
and relevant genetic features (loss of heterozygosity on 17p and 19q, EGFR amplification, and p53 mutations) in a retrospective study on 86 patients affected by glioblastoma multiforme: 72 patients
had a clinical history indicating de novo insurgence of the tumor and the remaining 14 were secondary glioblastoma multiforme.
Results: MGMT methylation was detected by methylation-specific PCR in 41 of 86 cases (47.7%; Meth+). Progression-free survival and
overall survival were significantly longer in Meth+ than in Meth− patients 10 versus 7 months ( P = 0.003, log-rank test) and 18 versus 14 months ( P = 0.0003, log-rank test), respectively. Mixed-nodular enhancement at magnetic resonance imaging was significantly more frequent
in Meth+ and secondary glioblastoma multiforme and ring enhancement in Meth− and primary glioblastoma multiforme ( P < 0.005). MGMT methylation was more present in secondary glioblastoma multiforme ( P = 0.006) and associated with loss of heterozygosity on 17p and/or 19q ( P = 0.005).
Conclusions: These observations suggest that MGMT methylation is part of a genetic signature of glioblastomas that developed from lower-grade
gliomas.
The R132H mutation of cytosolic isocitrate dehydrogenase (IDH1) is present in the majority of low grade gliomas.Immunotherapy in these tumors has an interesting, still unexploited, therapeutic ...potential, as they are less immunosuppressive than glioblastomas. Using site-directed mutagenesis we introduced the R132H mutation into the murine glioma cell line GL261,creating mIDH1-GL261. Presence of the mutation was confirmed by immunoblotting and production of the oncometabolite 2-hydroxyglutarate (2HG), demonstrated by mass spectrometry (LC-MS/MS) performed on cell supernatant. In vitro mIDH1-GL261 had different morphology but similar growth rate than parental GL261 (p-GL261). After intracranial injection, MRI suggested that the initial growth rate was slower in mIDH1-GL261 than p-GL261 gliomas but overall survival was similar. mIDH1-GL261 gliomas showed evidence of R132H expression and of intratumoral 2HG production (evaluated by MRS and LC-MS/MS). Immunizations were performed nine days after intracranial implantation of mIDH1- or p-GL261 cells by three subcutaneous injections of five different peptides encompassing the IDH1 mutation site, all emulsified with Montanide ISA-51, in association with GM-CSF. Control mice were injected with four ovalbumin peptides or vehicle. Mice with mIDH1-GL261 but not p-GL261 gliomas treated with mIDH1 peptides survived longer than controls; 25% of them were cured. Immunized mice showed higher amounts of peripheral CD8+ T cells, higher production of IFN-γ, and evidence of anti-mIDH1 antibodies.Immunizations led to intratumoral up-regulation of IFN-γ, granzyme-b and perforin-1 and down-regulation of TGF-β2 and IL-10. These results support the translational potential of immunotherapeutic targeting of gliomas carrying IDH1 mutations.
Abstract
Purpose: Recent data suggest that methylation of the DNA repair gene O6-methylguanine DNA methyltransferase (MGMT), by increasing the chemosensitivity of glioblastoma multiforme, is ...significantly associated with improved prognosis. Results in contradiction with these findings, however, are present in the literature and the clinical and genetic context framing MGMT methylation is poorly characterized.
Experimental Design: To address these issues, we have investigated the MGMT methylation status, clinical and magnetic resonance imaging characteristics, and relevant genetic features (loss of heterozygosity on 17p and 19q, EGFR amplification, and p53 mutations) in a retrospective study on 86 patients affected by glioblastoma multiforme: 72 patients had a clinical history indicating de novo insurgence of the tumor and the remaining 14 were secondary glioblastoma multiforme.
Results: MGMT methylation was detected by methylation-specific PCR in 41 of 86 cases (47.7%; Meth+). Progression-free survival and overall survival were significantly longer in Meth+ than in Meth− patients 10 versus 7 months (P = 0.003, log-rank test) and 18 versus 14 months (P = 0.0003, log-rank test), respectively. Mixed-nodular enhancement at magnetic resonance imaging was significantly more frequent in Meth+ and secondary glioblastoma multiforme and ring enhancement in Meth− and primary glioblastoma multiforme (P < 0.005). MGMT methylation was more present in secondary glioblastoma multiforme (P = 0.006) and associated with loss of heterozygosity on 17p and/or 19q (P = 0.005).
Conclusions: These observations suggest that MGMT methylation is part of a genetic signature of glioblastomas that developed from lower-grade gliomas.
Mutations in PSEN1 are responsible for familial Alzheimer’s disease (FAD) inherited as autosomal dominant trait, but also de novo mutations have been rarely reported in sporadic early-onset dementia ...cases. Parkinsonism in FAD has been mainly described in advanced disease stages. We characterized a patient presenting with early-onset dystonia-parkinsonism later complicated by dementia and myoclonus. Brain MRI showed signs of iron accumulation in the basal ganglia mimicking neurodegeneration with brain iron accumulation (NBIA) as well as fronto-temporal atrophy. Whole exome sequencing revealed a novel PSEN1 mutation and segregation within the family demonstrated the mutation arose de novo.
We suggest considering PSEN1 mutations in cases of dystonia-parkinsonism with positive DAT-Scan, later complicated by progressive cognitive decline and cortical myoclonus even without a dominant family history.
Meningiomas are the most frequent intracranial tumors. Surgery can be curative, but recurrences are possible. We performed gene expression analyses and loss of heterozygosity (LOH) studies looking ...for new markers predicting the recurrence risk. We analyzed expression profiles of 23 meningiomas (10 grade I, 10 grade II, and 3 grade III) and validated the data using quantitative polymerase chain reaction (qPCR). We performed LOH analysis on 40 meningiomas, investigating chromosomal regions on 1p, 9p, 10q, 14q, and 22q. We found 233 and 268 probe sets to be significantly down‐ and upregulated, respectively, in grade II or III meningiomas. Genes downregulated in high‐grade meningiomas were overrepresented on chromosomes 1, 6, 9, 10, and 14. Based on functional enrichment analysis, we selected LIM domain and actin binding 1 (LIMA1), tissue inhibitor of metalloproteinases 3 (TIMP3), cyclin‐dependent kinases regulatory subunit 2 (CKS2), leptin receptor (LEPR), and baculoviral inhibitor of apoptosis repeat‐containing 5 (BIRC5) for validation using qPCR and confirmed their differential expression in the two groups of tumors. We calculated ΔCt values of CKS2 and LEPR and found that their differential expression (C‐L index) was significantly higher in grade I than in grade II or III meningiomas (p < .0001). Interestingly, the C‐L index of nine grade I meningiomas from patients who relapsed in <5 years was significantly lower than in grade I meningiomas from patients who did not relapse. These findings indicate that the C‐L index may be relevant to define the progression risk in meningioma patients, helping guide their clinical management. A prospective analysis on a larger number of cases is warranted.
摘要
脑膜瘤是最常见的颅内肿瘤，可通过手术进行治疗，但有复发可能。我们进行基因表达分析和杂合性缺失（LOH）研究，以寻找预测脑膜瘤复发风险的新的标志物。我们分析了23例脑膜瘤（10例I级、10例II级和3例III级）的基因表达谱并用定量聚合酶链反应（qPCR）验证。对40例脑膜瘤进行LOH分析，检查1p、9p、10q、14q和22q染色体区域。我们发现，在II级或III级脑膜瘤，有233个探针集表达显著下调，有268个探针集表达显著上调。在高级别脑膜瘤，1、6、9、10、14号染色体的基因下调过表达。基于功能富集分析，我们选择了LIM结构域和肌动蛋白结合蛋白1（LIMA1）、金属蛋白酶组织抑制因子3（TIMP3）、细胞周期蛋白依赖性激酶调节亚基2（CKS2）、瘦素受体（LEPR）和凋亡重复序列杆状病毒抑制因子5（BIRC5）5个基因，使用qPCR验证其在两组肿瘤中的差异表达。我们计算了CKS2和LEPR的?Ct值，并发现它们的差异表达（C‐L指数）在I级脑膜瘤中显著高于II级或III级脑膜瘤（p<0.0001）。有趣的是，9例I级脑膜瘤患者在5年内复发，与其他I级脑膜瘤患者相比，复发患者标本的C‐L指数显著低于未复发患者的标本。这项研究表明，C‐L指数可能与脑膜瘤患者病情进展的风险相关，有助于指导患者的临床管理。还需要开展较大样本的前瞻性分析。
Gene expression analyses and loss of heterozygosity studies were performed to find new markers relevant to predict meningioma recurrence risk. The differential expression (C‐L index) of CKS2 and LEPR was significantly higher in grade I than in grade II or III meningiomas, suggesting that the C‐L index may be relevant to define progression risk.
Several examples have always illustrated how access to large numbers of biospecimens and associated data plays a pivotal role in the identification of disease genes and the development of ...pharmaceuticals. Hence, allowing researchers to access to significant numbers of quality samples and data, genetic biobanks are a powerful tool in basic, translational and clinical research into rare diseases. Recently demand for well-annotated and properly-preserved specimens is growing at a high rate, and is expected to grow for years to come. The best effective solution to this issue is to enhance the potentialities of well-managed biobanks by building a network.Here we report a 5-year experience of the Telethon Network of Genetic Biobanks (TNGB), a non-profit association of Italian repositories created in 2008 to form a virtually unique catalogue of biospecimens and associated data, which presently lists more than 750 rare genetic defects. The process of TNGB harmonisation has been mainly achieved through the adoption of a unique, centrally coordinated, IT infrastructure, which has enabled (i) standardisation of all the TNGB procedures and activities; (ii) creation of an updated TNGB online catalogue, based on minimal data set and controlled terminologies; (iii) sample access policy managed via a shared request control panel at web portal. TNGB has been engaged in disseminating information on its services into both scientific/biomedical - national and international - contexts, as well as associations of patients and families. Indeed, during the last 5-years national and international scientists extensively used the TNGB with different purposes resulting in more than 250 scientific publications. In addition, since its inception the TNGB is an associated member of the Biobanking and Biomolecular Resources Research Infrastructure and recently joined the EuroBioBank network. Moreover, the involvement of patients and families, leading to the formalization of various agreements between TNGB and Patients' Associations, has demonstrated how promoting Biobank services can be instrumental in gaining a critical mass of samples essential for research, as well as, raising awareness, trust and interest of the general public in Biobanks. This article focuses on some fundamental aspects of networking and demonstrates how the translational research benefits from a sustained infrastructure.
In recent years the amount of information concerning the genetics and the biology of gliomas, and particularly of glioblastoma multiforme, increased steadily. Such an increase has been paralleled by ...the technological progress of MRI. The merging of these scientific areas, as summarized in this review, is helping the stratification of glioma patients for clinical trials and their clinical follow-up. Although available therapeutic options appear limited in number, it is likely that in the next 5 years, both as a consequence of the increased knowledge due to genomic sequencing of hundreds of glioblastoma specimens and to continuous improvements of MRI, new perspectives will be available for these patients, with a sizable impact on their prognosis.
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