scholarly journals 60 Are gangliogliomas in children and adults disorders of nervous system development?

Author(s):  
Qiang Jiang ◽  
Jamie Zagozewski ◽  
Paolo Nozza ◽  
Beverly Wilson ◽  
Frank Van Landeghem ◽  
...  

INTRODUCTION: Gangliogliomas (GGs) are neuroepithelial tumours of the central nervous system (CNS) composed of mature ganglion cells or a mixed population of ganglion and glial cells. Microarray data of low grade gliomas (LGG) including GGs revealed overexpression of the Dlx2 gene, a homeobox gene essential for interneuron migration and differentiation. We hypothesized that GGs are arrested in development, and began to explore the role of the Dlx2 gene. BRAF rearrangements and BRAF V600E point mutations have been reported in pediatric LGG. METHODS: DLX2 expression was examined in GGs using immunofluorescence (IF) and immunohistochemistry (IHC) labelling of formalin fixed paraffin embedded (FFPE) tissue sections, along with staining of glial and neuronal markers. BRAF mutations were detected using a commercial antibody and/or sequence verification of the DNA extracted from the FFPE blocks. RESULTS: In the Discovery cohort 10/30 were DLX2+ (33.3%) and in the Validation cohort 15/40 were DLX2+ (37.5%). Of these 15 cases, 15 were GFAP+ (100%), 15 were synaptophysin and/or NeuN+ (100%), and 13 were OLIG2+ (86.7%); 6 had a BRAF V600E mutation (40.0%). For the Validation cohort of 40 GGs, 28 were OLIG2+ (70.0%); 13/28 co-expressed DLX2 (46.4%). 18/40 cases had a BRAF V600 mutation(17 V600E, 1 V600G; 45.0%) and 6/18 were DLX2+ (33.3%). CONCLUSIONS: DLX2 is expressed in GGs in both neuronal and glial marker expressing tumour cells. Our results support that GGs arise from CNS progenitors arrested at the neuronal-glial cell fate “decision” point.

Author(s):  
Q. Jiang ◽  
J. Zagozewski ◽  
P. Nozza ◽  
B. Wilson ◽  
F. Van Landeghem ◽  
...  

Gangliogliomas (GG) are low grade neuroepithelial tumours of the central nervous system (CNS) comprised of neoplastic glial and neuronal cells. There are no animal models or cell lines to study. Microarray data of a panel of low grade gliomas including GG revealed overexpression of the DLX2 homeobox gene required for tangential interneuronal migration and differentiation in the embryonic forebrain. We hypothesized that DLX2 regulates neural versus glial cell fate decisions in CNS progenitors and that GG are arrested in development. METHODS: DLX2 expression was examined along with glial fibrillary acidic protein (GFAP; glial marker) and synaptophysin and/or NeuN (neuronal markers) expression in a cohort of GG tumours using immunohistochemistry and dual immunofluorescence labelling of formalin fixed paraffin embedded (FFPE) tissue sections. BRAF mutational status was also assessed. RESULTS: In our discovery cohort (Genoa), 10/30 samples (33%) expressed DLX2. In our validation cohort (Edmonton), 22/36 (61%) expressed nuclear DLX2 and 12/22 DLX2+cases had BRAF mutations (55%; 11 V600E, 1 V600G). 12/18 cases with BRAF mutations were DLX2+(67%). One heavily pre-treated child with progressive cervicomedullary GG has had a very good partial response to BRAF inhibitor therapy. All 22 DLX2+tumours co-expressed GFAP (100%) and 21/22 (95%) also expressed synaptophysin or NeuN. CONCLUSIONS: Our results support GG as neurodevelopmental tumours arising from bipotential CNS progenitors that are arrested at the neural-glial cell fate "decision" point. Biological or differentiation-based treatments could be considered+/- BRAF inhibitors for those GG with/without the V600E mutation, respectively.


Development ◽  
2001 ◽  
Vol 128 (5) ◽  
pp. 711-722 ◽  
Author(s):  
T.E. Rusten ◽  
R. Cantera ◽  
J. Urban ◽  
G. Technau ◽  
F.C. Kafatos ◽  
...  

Genes of the spalt family encode nuclear zinc finger proteins. In Drosophila melanogaster, they are necessary for the establishment of head/trunk identity, correct tracheal migration and patterning of the wing imaginal disc. Spalt proteins display a predominant pattern of expression in the nervous system, not only in Drosophila but also in species of fish, mouse, frog and human, suggesting an evolutionarily conserved role for these proteins in nervous system development. Here we show that Spalt works as a cell fate switch between two EGFR-induced cell types, the oenocytes and the precursors of the pentascolopodial organ in the embryonic peripheral nervous system. We show that removal of spalt increases the number of scolopodia, as a result of extra secondary recruitment of precursor cells at the expense of the oenocytes. In addition, the absence of spalt causes defects in the normal migration of the pentascolopodial organ. The dual function of spalt in the development of this organ, recruitment of precursors and migration, is reminiscent of its role in tracheal formation and of the role of a spalt homologue, sem-4, in the Caenorhabditis elegans nervous system.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e14657-e14657 ◽  
Author(s):  
Pamela Francesca Guglielmini ◽  
Maura Rossi ◽  
Federica Grosso ◽  
Sara Orecchia ◽  
Marco Galliano ◽  
...  

e14657 Background: KRAS and BRAF mutations have prognostic and predictive value in colorectal cancer and are predominantly mutually exclusive. Only a few cases of double mutations (DM) have been reported so far but the actual incidence and presumed role in worsening prognosis is still unknown. Here we report on a series of KRAS and BRAF mutations, focusing on three cases of KRAS and BRAF DM. Methods: since May 2010, 316 consecutive colorectal cancer samples were collected by our Oncology Department; ten patients (3%) had high risk localized disease and 306 (97%) metastatic disease. Genome DNA from formalin-fixed paraffin embedded samples with tumor cells > 50% was analyzed by reverse dot blot with KRAS-BRAF StripAssay kit (Nuclear Laser Medicine). Results: KRAS point mutations were found in 141 patients (44.6%): 32% G12V, 30.5% G12D, 14.9% G13D, 6.4% G12S, 5.7% G12C, 4.9% G12A, 4.9% G12R, 0.7% G13C; V600E BRAF point mutation was found in 21 patients (6.6%). Three patients (1%) displayed DM: 2 KRAS G13D + BRAF V600E (A and B) and 1 KRAS G12V + BRAF V600E (C). Patients A and C, both aged 59, presented with metastatic disease. Patient A had a rectal primary, a single lung lesion and mediastinal nodes. He failed first line FOLFOX4 plus bevacizumab and underwent salvage surgery both on primary and metastatic disease. He relapsed in 3 months with liver and brain metastasis and died after one year from diagnosis. Patient B had huge liver lesions at presentation. She progressed after 3 courses of FOLFIRI and died after 6 months from diagnosis. Patient C was operated on for a right colon cancer, G3, pT2N2, stage IIIB with lymph vascular invasion and had adjuvant FOLFOX 4. The 6-month assessment did not show relapse. Conclusions: in our series KRAS mutation incidence was in line with literature, but G12V was far more frequent. KRAS-BRAF DM accounted for 1% of all cases and the 2 patients with metastatic disease had an aggressive course with a much lower than expected survival. To our knowledge no series of DM have been described, hindering the understanding of their biological meaning. According to our experience, metastatic double mutated patients do not respond to standard therapy and should be treated with new drugs combinations in clinical trials.


2021 ◽  
Author(s):  
Valeria De La Rosa-Reyes ◽  
Mildred V Duprey-Díaz ◽  
Jonathan M Blagburn ◽  
Rosa E Blanco

Retinoic acid (RA) plays major roles during nervous system development, and during regeneration of the adult nervous system. We have previously shown that components of the RA signaling pathway are upregulated after optic nerve injury, and that exogenous application of all-trans retinoic acid (ATRA) greatly increases the survival of axotomized retinal ganglion cells (RGCs). The objective of the present study is to investigate the effects of ATRA application on the macrophages in the optic nerve after injury, and to determine whether this affects axonal regeneration. The optic nerve was crushed and treated with PBS, ATRA and/or clodronate-loaded liposomes. Nerves were examined at one and two weeks after axotomy with light microscopy, immunocytochemistry and electron microscopy. ATRA application to the optic nerve caused transient increases in the number of macrophages and microglia one week after injury. The macrophages are consistently labeled with M2-type markers, and have considerable phagocytic activity. ATRA increased ultrastructural features of ongoing phagocytic activity in macrophages at one and two weeks. ATRA treatment also significantly increased the numbers of regenerating GAP-43-labeled axons. Clodronate liposome treatment depleted macrophage numbers by 80%, completely eliminated the ATRA-mediated increase in axonal regeneration, and clodronate treatment alone decreased axonal numbers by 30%. These results suggest that the success of axon regeneration is partially dependent on the presence of debris-phagocytosing macrophages, and that the increases in regeneration caused by ATRA are in part due to their increased numbers. Further studies will examine whether macrophage depletion affects RGC survival.


2020 ◽  
Vol 10 (6) ◽  
pp. 1949-1962 ◽  
Author(s):  
Elyse L. Christensen ◽  
Alexandra Beasley ◽  
Jessica Radchuk ◽  
Zachery E. Mielko ◽  
Elicia Preston ◽  
...  

Proper nervous system development is required for an organism’s survival and function. Defects in neurogenesis have been linked to neurodevelopmental disorders such as schizophrenia and autism. Understanding the gene regulatory networks that orchestrate neural development, specifically cascades of proneural transcription factors, can better elucidate which genes are most important during early neurogenesis. Neurogenins are a family of deeply conserved factors shown to be both necessary and sufficient for the development of neural subtypes. However, the immediate downstream targets of neurogenin are not well characterized. The objective of this study was to further elucidate the role of ngn-1/neurogenin in nervous system development and to identify its downstream transcriptional targets, using the nematode Caenorhabditis elegans as a model for this work. We found that ngn-1 is required for axon outgrowth, nerve ring architecture, and neuronal cell fate specification. We also showed that ngn-1 may have roles in neuroblast migration and epithelial integrity during embryonic development. Using RNA sequencing and comparative transcriptome analysis, we identified eight transcription factors (hlh-34/NPAS1, unc-42/PROP1, ceh-17/PHOX2A, lim-4/LHX6, fax-1/NR2E3, lin-11/LHX1, tlp-1/ZNF503, and nhr-23/RORB) whose transcription is activated, either directly or indirectly, by ngn-1. Our results show that ngn-1 has a role in transcribing known terminal regulators that establish and maintain cell fate of differentiated neural subtypes and confirms that ngn-1 functions as a proneural transcription factor in C. elegans neurogenesis.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yong Li ◽  
Gang Deng ◽  
Yangzhi Qi ◽  
Huikai Zhang ◽  
Hongxiang Jiang ◽  
...  

Background. LUZP2 is a protein limitedly expressed in the brain and spinal cord, while there are few studies on it in brain tumors. Low-grade glioma (LGG) is one of the most common brain tumors. However, the biological behavior of LGG is not very clear at present. This study was aimed at exploring the role of LUZP2 in LGG. Methods. By data mining in The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA), the expression, clinical characteristics, and potential regulatory mechanism of LUZP2 in LGG were assessed. The regulatory miRNAs of LUZP2 were predicted using miRDB, TargetScan, and miRTarBase. Meanwhile, the potential biological function of coexpressed genes was investigated by GO and KEGG analyses. Results. LUZP2 expression was downregulated with the increase of tumor grade (p<0.05). Low LUZP2 expression independently predicted poor OS in LGG in TCGA cohort and the CGGA part B and part C cohorts (all p<0.001). Additionally, LUZP2 was targeted by miR-142-5p according to 2 prediction databases and 1 validated database, which was negatively related to LUZP2 mRNA expression (p<0.001). Kaplan-Meier analyses demonstrated that low miR-142-5p expression was significantly associated with poor OS (p<0.001). Furthermore, coexpression genes of LUZP2 were significantly involved in nervous system development and metabolic pathways.Conclusions. LUZP2 may be crucial for nervous system extracellular matrix development and serve as an important clinical biomarker for LGG patients. miR-142-5p upregulation could be the upstream regulator that contributed to LUZP2 downregulation.


2015 ◽  
Vol 33 (9) ◽  
pp. 1015-1022 ◽  
Author(s):  
Matthew Mistry ◽  
Nataliya Zhukova ◽  
Daniele Merico ◽  
Patricia Rakopoulos ◽  
Rahul Krishnatry ◽  
...  

Purpose To uncover the genetic events leading to transformation of pediatric low-grade glioma (PLGG) to secondary high-grade glioma (sHGG). Patients and Methods We retrospectively identified patients with sHGG from a population-based cohort of 886 patients with PLGG with long clinical follow-up. Exome sequencing and array CGH were performed on available samples followed by detailed genetic analysis of the entire sHGG cohort. Clinical and outcome data of genetically distinct subgroups were obtained. Results sHGG was observed in 2.9% of PLGGs (26 of 886 patients). Patients with sHGG had a high frequency of nonsilent somatic mutations compared with patients with primary pediatric high-grade glioma (HGG; median, 25 mutations per exome; P = .0042). Alterations in chromatin-modifying genes and telomere-maintenance pathways were commonly observed, whereas no sHGG harbored the BRAF-KIAA1549 fusion. The most recurrent alterations were BRAF V600E and CDKN2A deletion in 39% and 57% of sHGGs, respectively. Importantly, all BRAF V600E and 80% of CDKN2A alterations could be traced back to their PLGG counterparts. BRAF V600E distinguished sHGG from primary HGG (P = .0023), whereas BRAF and CDKN2A alterations were less commonly observed in PLGG that did not transform (P < .001 and P < .001 respectively). PLGGs with BRAF mutations had longer latency to transformation than wild-type PLGG (median, 6.65 years [range, 3.5 to 20.3 years] v 1.59 years [range, 0.32 to 15.9 years], respectively; P = .0389). Furthermore, 5-year overall survival was 75% ± 15% and 29% ± 12% for children with BRAF mutant and wild-type tumors, respectively (P = .024). Conclusion BRAF V600E mutations and CDKN2A deletions constitute a clinically distinct subtype of sHGG. The prolonged course to transformation for BRAF V600E PLGGs provides an opportunity for surgical interventions, surveillance, and targeted therapies to mitigate the outcome of sHGG.


2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tania Moujaber ◽  
Dariush Etemadmoghadam ◽  
Catherine J. Kennedy ◽  
Yoke-Eng Chiew ◽  
Rosemary L. Balleine ◽  
...  

Purpose Low-grade serous ovarian carcinoma (LGSC) responds poorly to chemotherapy and is characterized by activating mutations in the Ras sarcoma–mitogen-activated protein kinase (RAS-MAPK) pathway, including oncogenic BRAF. However, response to BRAF inhibitors is tumor-type specific. Significant improvement in survival is seen in patients with BRAF-mutant melanoma, but other cancer types, such as colorectal cancers, are generally less sensitive. We examined the frequency and characteristics of BRAF-mutated LGSC and described the response to treatment with BRAF inhibitors. Patients and Methods Mutations were assessed in LGSC (N = 65) by using targeted, exome, and whole-genome sequencing. Patient characteristics, treatment, and clinical outcome were assessed, and the median follow-up time was more than 5 years. BRAF inhibitors were trialed in two patients with a somatic BRAF V600E mutation: one patient received dabrafenib monotherapy and was monitored clinically, biochemically (cancer antigen [CA]-125 levels), and with positron emission tomography (PET) imaging. Expression of the BRAF V600E protein in this patient was assessed by immunohistochemistry. Results Among patients with LGSC, nine (13.8%) of 65 had a somatic BRAF mutation. Of the nine patients with BRAF mutation–positive LGSC, four experienced progressive disease that did not respond to conventional chemotherapy. Two of the patients experienced progression quickly and died as a result of disease progression, and two received targeted treatment. Two patients with BRAF V600E mutation received BRAF inhibitors at relapse and both achieved durable responses. Conclusion BRAF mutations are not uncommon in patients with LGSC and should be routinely tested, because BRAF inhibitors can be an effective treatment for these patients. The results highlight the need for targeted treatment in this rare tumor type, and a prospective study is needed to formally assess the response rate and clinical benefit.


2020 ◽  
Vol 10 (9) ◽  
pp. 3071-3085
Author(s):  
Wendy Aquino-Nunez ◽  
Zachery E Mielko ◽  
Trae Dunn ◽  
Elise M Santorella ◽  
Ciara Hosea ◽  
...  

Abstract Identifying the mechanisms behind neuronal fate specification are key to understanding normal neural development in addition to neurodevelopmental disorders such as autism and schizophrenia. In vivo cell fate specification is difficult to study in vertebrates. However, the nematode Caenorhabditis elegans, with its invariant cell lineage and simple nervous system of 302 neurons, is an ideal organism to explore the earliest stages of neural development. We used a comparative transcriptome approach to examine the role of cnd-1/NeuroD1 in C. elegans nervous system development and function. This basic helix-loop-helix transcription factor is deeply conserved across phyla and plays a crucial role in cell fate specification in both the vertebrate nervous system and pancreas. We find that cnd-1 controls expression of ceh-5, a Vax2-like homeobox class transcription factor, in the RME head motorneurons and PVQ tail interneurons. We also show that cnd-1 functions redundantly with the Hox gene ceh-13/labial in defining the fate of DD1 and DD2 embryonic ventral nerve cord motorneurons. These data highlight the utility of comparative transcriptomes for identifying transcription factor targets and understanding gene regulatory networks.


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