Project description:The R132H mutation in the metabolic enzyme isocitrate dehydrogenase 1 (IDH1) is the most important prognostic factor for survival of glioma patients. This resulted in many studies investigating the effects of this mutation, including those on energy metabolism. This led to the discovery of a panel of enzymes mainly involved in glutamate anaplerosis and aerobic glycolysis that change in abundance as a result of the IDH1 mutation. To further study these changes and investigate the therapeutic value of inhibitors of IDH1 R132H-associated metabolic pathways, appropriate glioma models are required that mimic in vivo metabolism as good as possible. To investigate how metabolism is affected by in vitro cell culture, we here compared surgically obtained snap frozen glioma tissues with their corresponding primary glioma cell culture models with a previously developed targeted mass spectrometry proteomic assay. We determined the relative abundance of a panel of metabolic enzymes. Results confirmed increased glutamate use and decreased aerobic glycolysis in resected IDH1 R132H glioma tissue samples. However, these metabolic profiles were not reflected in the paired glioma culture samples. Analysis of orthotopic glioma xenograft samples with and without the IDH1 mutation revealed metabolic profiles that more closely resembled clinical counterparts. We suggest that culture conditions and tumor microenvironment play a crucial role in maintaining the in vivo metabolic situation in cell culture models. For this reason, new models that more closely resemble the in vivo microenvironment, such as 3-dimensional cell co-cultures or organotypic multicellular spheroid models, need to be developed and investigated.
Project description:The R132H mutation in the metabolic enzyme isocitrate dehydrogenase 1 (IDH1) is the most important prognostic factor for survival of glioma patients. This resulted in many studies investigating the effects of this mutation, including those on energy metabolism. This led to the discovery of a panel of enzymes mainly involved in glutamate anaplerosis and aerobic glycolysis that change in abundance as a result of the IDH1 mutation. To further study these changes and investigate the therapeutic value of inhibitors of IDH1 R132H-associated metabolic pathways, appropriate glioma models are required that mimic in vivo metabolism as good as possible. To investigate how metabolism is affected by in vitro cell culture, we here compared surgically obtained snap frozen glioma tissues with their corresponding primary glioma cell culture models with a previously developed targeted mass spectrometry proteomic assay. We determined the relative abundance of a panel of metabolic enzymes. Results confirmed increased glutamate use and decreased aerobic glycolysis in resected IDH1 R132H glioma tissue samples. However, these metabolic profiles were not reflected in the paired glioma culture samples. Analysis of orthotopic glioma xenograft samples with and without the IDH1 mutation revealed metabolic profiles that more closely resembled clinical counterparts. We suggest that culture conditions and tumor microenvironment play a crucial role in maintaining the in vivo metabolic situation in cell culture models. For this reason, new models that more closely resemble the in vivo microenvironment, such as 3-dimensional cell co-cultures or organotypic multicellular spheroid models, need to be developed and investigated.
Project description:Diffuse midline glioma (DMG) is a lethal pediatric brain cancer with limited treatment options. We developed a human brainstem organoid model to study H3.3K27M-driven DMG, enabling formation of patient-like tumors with molecular heterogeneity. To characterize the resulting tumor we performed DNA methylation and compared the generated tumor with methylation data from DMG, pGBM and PFA ependymoma patients.
Project description:NK cells were purified from peripheral blood of healthy controls (n = 5), individuals with latent tuberculosis infection (n = 5), and active tuberculosis patients (n = 5). Total RNA was isolated from purified NK cells using RNA Isolation Kit (Dongsheng, R1061) according to the manufacturer's instructions. RNA Sequencing was conducted using the Illumina HiSeq X Ten platform (Novogene Bioinformatics Technology Co., Ltd.) with paired-end 150-bp reads.
Project description:The outcome for children with high-grade gliomas (HGG) remains dismal, with a two-year survival rate of only 10-30%. Approximately half of pediatric HGGs are diffuse intrinsic pontine glioma (DIPG), a brainstem tumor that arises almost exclusively in children. Genome-wide analyses of copy number imbalances previously showed that platelet derived growth factor receptor alpha (PDGFRA) is the most frequent target of focal amplification in pediatric HGGs. To determine whether the PDGFRA is also targeted by more subtle mutations not detected by copy number analysis, we sequenced all PDGFRA coding exons from a cohort of pediatric HGGs. Somatic activating mutations were identified in 14.4% (13/90) of non-brainstem pediatric HGGs and 4.7% (2/43) of DIPGs, including missense mutations and in-frame deletions and insertions not previously described. 40% of tumors with mutation showed concurrent amplification, while 60% carried heterozygous mutations. Six different mutations impacting different domains all resulted in ligand-independent receptor activation that was blocked by small molecule inhibitors of PDGFR. Expression of mutants in p53-null primary mouse astrocytes conferred a proliferative advantage in vitro, and generated HGGs in vivo with complete penetrance when implanted into brain. The gene expression signatures reflected the spectrum of human diffuse HGGs. PDGFRA intragenic deletion of exons 8 and 9 were previously shown in adult HGG, but were not detected in 83 non-brainstem pediatric HGG and 57 DIPGs. Thus, a distinct spectrum of mutations confers constitutive receptor activation and oncogenic activity to PDGFR in childhood HGG. To better understand the consequence of PDGFRα mutation in pediatric gliomagenesis, retroviral constructs expressing wild-type PDGFRα or six selected PDGFRα mutants that affect different regions of the receptor were generated for functional studies. p53-null primary mouse astrocyte (PMA) cultures were chosen as a relevant cellular background to assess PDGFRα function.
Project description:Nipple aspriate fluid (NAF) were obtained from 7 women including 3 breast cancer patients. Cell-free DNA (cfDNA) were isolated and bisulfite sequencing using Illumina HiSeq X Ten platform.
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.