Project description:Gliomas arising in the brainstem are rare tumours worldwide that are difficult to surgically resect, and the involved miRNAs and signaling pathways associated with brainstem gliomas (BSGs) are largely unclear. Tumours in the control nervous system owned a WHO classification, which are of great significance to guide the treatment and to evaluate prognosis. To determine grade-associated miRNAs in BSGs, this study performed microarray of 10 low-grade and 15 high grade BSGs.
Project description:Gliomas arising in the brainstem and thalamus are devastating tumors that are difficult to surgically resect due to their proximity to eloquent brain structures. Here, we performed a comprehesive genomic and epigenomic study, using gene expression and methylation microarrays, to research on th different genomic and epigenetic signatures between brainstem, thalamic, and supratentorial gliomas. Comparison of brainstem, thalamic and supratentorial gliomas
Project description:Gliomas arising in the brainstem and thalamus are devastating tumors that are difficult to surgically resect due to their proximity to eloquent brain structures. Here, we performed a comprehesive genomic and epigenomic study, using gene expression and methylation microarrays, to research on th different genomic and epigenetic signatures between brainstem, thalamic, and supratentorial gliomas.
Project description:Using the RCAS/tv-a system, we induced murine brainstem gliomas (PDGF-B; p53 loss using RCAS-Cre with and without H3.3K27M) in Nestin tv-a; p53 floxed mice
Project description:Purpose: More than 90% of children with diffuse intrinsic pontine glioma (DIPG) die within 2 years of diagnosis. There is a dire need to identify therapeutic targets, however lack of patient material for research has limited progress. We evaluated a large cohort of diffuse intrinsic pontine gliomas (DIPGs) to identify recurrent genomic abnormalities and gene expression signatures underlying DIPG. Patients and Methods: We used single nucleotide polymorphism arrays to evaluate genomic copy number imbalances in 43 DIPGs from 40 patients and in 8 low-grade exophytic brainstem gliomas. Gene expression arrays were used to evaluate expression signatures from 27 DIPGs, 6 low-grade exophytic brainstem gliomas and 66 low-grade gliomas arising outside the brainstem. Results: Frequencies of specific large-scale and focal imbalances varied significantly between DIPGs and pediatric glioblastomas outside the brainstem. Focal amplifications of genes within the receptor tyrosine kinase-Ras-PI3-kinase signaling pathway were found in 47% of DIPG, with PDGFRA and MET showing the highest frequency. 30% of DIPG contained focal amplifications of cell-cycle regulatory genes controlling RB phosphorylation, and 21% had concurrent amplification of genes from both pathways. Some tumors showed heterogeneity in amplification patterns. DIPGs showed distinct gene expression signatures relating to developmental processes compared to pediatric glioblastomas arising outside the brainstem, while expression signatures of low-grade exophytic brainstem gliomas were similar to low-grade gliomas outside the brainstem. Copy number analaysis: 43 DIPG samples, 8 Low Grade Gliomas using SNP6.0. Available matched normals are also profiled with SNP6.0. Expression analysis: 29 DIPG samples, 6 Low grade samples Please contact Suzanne Baker at Suzanne.Baker@stjude.org for CEL files and genotype calls.
Project description:Purpose: More than 90% of children with diffuse intrinsic pontine glioma (DIPG) die within 2 years of diagnosis. There is a dire need to identify therapeutic targets, however lack of patient material for research has limited progress. We evaluated a large cohort of diffuse intrinsic pontine gliomas (DIPGs) to identify recurrent genomic abnormalities and gene expression signatures underlying DIPG. Patients and Methods: We used single nucleotide polymorphism arrays to evaluate genomic copy number imbalances in 43 DIPGs from 40 patients and in 8 low-grade exophytic brainstem gliomas. Gene expression arrays were used to evaluate expression signatures from 27 DIPGs, 6 low-grade exophytic brainstem gliomas and 66 low-grade gliomas arising outside the brainstem. Results: Frequencies of specific large-scale and focal imbalances varied significantly between DIPGs and pediatric glioblastomas outside the brainstem. Focal amplifications of genes within the receptor tyrosine kinase-Ras-PI3-kinase signaling pathway were found in 47% of DIPG, with PDGFRA and MET showing the highest frequency. 30% of DIPG contained focal amplifications of cell-cycle regulatory genes controlling RB phosphorylation, and 21% had concurrent amplification of genes from both pathways. Some tumors showed heterogeneity in amplification patterns. DIPGs showed distinct gene expression signatures relating to developmental processes compared to pediatric glioblastomas arising outside the brainstem, while expression signatures of low-grade exophytic brainstem gliomas were similar to low-grade gliomas outside the brainstem.
Project description:Diffuse midline glioma (DMG) identifies gliomas originating in the thalami, brainstem, cerebellum and spine. Within this entity, tumours that infiltrate the pons, called diffuse intrinsic pontine gliomas (DIPGs), have a rapid onset and devastating neurological symptoms. Radiotherapy is the only intervention that is able to modify the disease course, albeit not in a curative way. In recent years, liquid biopsies have represented the next step in clinical diagnostics due to their easily accessible nature. The purpose of this study is to profile circulating miRNA expression to disclose a potential prognostic signature with clinical impact.
Project description:To investigate the regulatory mechanisms governing the malignant signature of different gliomas we analyzed microRNA expression profiles in human tumor samples of world health organization (WHO) grade I (benign tumors), II (low grade tumors) and IV (high grade tumors) and from primary cultures obtained from tumor samples of grade II and IV. Patients This study included tumor samples histologically verified as astrocytic gliomas obtained from patients who had undergone craniotomy for microsurgical tumor removal. According to the revised WHO classification, tumors were diagnosed as: grade I or pilocytic astrocytomas; grade II or diffuse fibrillary astrocytomas; grade IV or glioblastoma multiforme. Primary cell cultures from grade II and grade IV gliomas were also obtained and miRNA expression in these cultures were analyzed RNA extraction Total RNA, including small RNA, was isolated from tissue samples using the mirVanaTM miRNA Isolation Kit (Ambion) following the standard protocol. The quantity and quality of the purified RNA was evaluated by spectrophotometric analysis and electrophoresis on denaturing gel of acrylamide. Multiplex Real-Time Quantitative Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) The miRNAs were first converted to cDNA using Multiplex RT for TaqMan Array Human MicroRNA Panel. The RT Master mix included 100 mM each of dNTPs , 50 U/ml MultiScrabe reverse transcriptase (Applied Biosystems), 20 U/M-BM-5l RNase inhibitor (Applied Biosystems) and 10X RT Buffer. The 10 M-BM-5l reactions, including 7 M-BM-5l of RT master mix, 2 M-BM-5l of purified microRNA and 1 M-BM-5l of Multiplex RT Human primer pool (Applied Biosystem), were incubated in ice for 5 min and then in a thermal cycler for 30 min at 16M-BM-0C, 30 min at 42M-BM-0C, 5 min at 85M-BM-0C, and then hold at 4M-BM-0C. miRNA levels were normalized to the expression of small nucleolar RNAs, RNU44, RNU48 and RNU6B. All reverse transcriptase reactions, including no-template controls and RT controls, were run in duplicate. Real-time PCR was performed using a standard TaqMan PCR kit procedure on an M-bM-^@M-^\Real Time Fast 7900 HTM-bM-^@M-^] PCR System (Applied Biosystems). The 100 M-BM-5l PCR included 50 M-BM-5l RT product (before diluited 1:60) and 50 M-BM-5l TaqMan Universal PCR Master Mix (2X) (Applied Biosystems). The total volume were loaded into Card TaqMan Low Density Array Human MicroRNA Panel (Applied Biosystem) including a total of 384 human microRNAs publicated on databases www.sanger.ac.uk. The reaction cards was runned at 50M-BM-0C for 2 min and 95M-BM-0C for 10 min, followed by 40 cycles of 97M-BM-0C for 30s and 59,7M-BM-0C for 1 min. All reactions were run in triplicate. Analysis of data was performed using the SDS 2.3 software using the 2-M-bM-^HM-^FM-bM-^HM-^FCt (relative quantitative) method . The M-bM-^HM-^FCt of every miRNA was determined in relation to the endogenous control RNA U6 that was invariably expressed in all samples. The M-bM-^HM-^FM-bM-^HM-^FCt value was determined in relation to the calibrator, namely the normal brain tissue. Resulting data were grouped according to the tumor grading e selectioned using a cut-off value of 3. Results were expressed as M-bM-^@M-^\fold changeM-bM-^@M-^] over normal brain tissue. We analyzed two samples of grade I, two samples of grade II, two samples of grade IV gliomas. Four samples form norma brain were used as norma control. Primary cell cultures form grade II and grade IV samples were used for the analysis. All reverse transcriptase reactions, including no-template controls and RT controls, were run in triplicate.
Project description:Diffuse intrinsic pontine gliomas (DIPGs) are highly lethal childhood brain tumors. Their unique genetic makeup, pathological heterogeneity, and brainstem location all present challenges to treatment. Developing mouse models that accurately reflect each of these distinct features will be critical to advance our understanding of DIPG development, progression, and therapeutic resistance. The aim of this study was to generate new mouse models of DIPG, and characterize the role of specific oncogenic combinations in DIPG pathogenesis. We used in utero electroporation (IUE) to transfect neural stem cells in the developing brainstem with PiggyBac DNA transposon plasmids. Combinations of PDGFB or PdgfraD842V, dominant negative Trp53 (DNp53), and H3.3K27M expression induced fully penetrant brainstem gliomas. IUE enabled the targeted transfection of brainstem neural stem cells. PDGFB + DNp53 induced the rapid development of grade-IV gliomas. PdgfraD842V + DNp53 produced slower forming grade-III gliomas. Addition of H3.3K27M only significantly accelerated PdgfraD842V DIPG development. Glioma subgroup molecular signatures were associated with differences in bulk PDGFB and PdgfraD842V tumor composition. H3.3K27M induced both overlapping and unique gene expression changes in PDGFB and PdgfraD842V tumors. Paracrine effects of PDGFB promote disruption of pericyte-endothelial interactions and angiogenesis in PDGFB DIPG mouse models. Brainstem targeted in utero electroporation provides a rapid and flexible system to generate diverse DIPG mouse models. Using IUE to investigate mutation and pathohistological heterogeneity of DIPG will provide a valuable tool for future genetic and preclinical studies.