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1.
Nat Commun ; 15(1): 7857, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39251578

RESUMO

Glioblastoma remains one of the deadliest brain malignancies. First-line therapy consists of maximal surgical tumor resection, accompanied by chemotherapy and radiotherapy. Malignant cells escape surgical resection by migrating into the surrounding healthy brain tissue, where they give rise to the recurrent tumor. Based on gene expression, tumor cores can be subtyped into mesenchymal, proneural, and classical tumors, each being associated with differences in genetic alterations and cellular composition. In contrast, the adjacent brain parenchyma where infiltrating malignant cells escape surgical resection is less characterized in patients. Using spatial transcriptomics (n = 11), we show that malignant cells within proneural or mesenchymal tumor cores display spatially organized differences in gene expression, although such differences decrease within the infiltrated brain tissue. Malignant cells residing in infiltrated brain tissue have increased expression of genes related to neurodevelopmental pathways and glial cell differentiation. Our findings provide an updated view of the spatial landscape of glioblastomas and further our understanding of the malignant cells that infiltrate the healthy brain, providing new avenues for the targeted therapy of these cells after surgical resection.


Assuntos
Neoplasias Encefálicas , Encéfalo , Regulação Neoplásica da Expressão Gênica , Glioblastoma , Receptores Notch , Transdução de Sinais , Humanos , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Receptores Notch/metabolismo , Receptores Notch/genética , Encéfalo/metabolismo , Encéfalo/patologia , Transcriptoma , Sinapses/metabolismo , Masculino , Feminino , Linhagem Celular Tumoral , Neuroglia/metabolismo , Neuroglia/patologia , Diferenciação Celular/genética
2.
Nat Commun ; 15(1): 7280, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39179527

RESUMO

Spatially resolved transcriptomics has revolutionized RNA studies by aligning RNA abundance with tissue structure, enabling direct comparisons between histology and gene expression. Traditional approaches to identifying signature genes often involve preliminary data grouping, which can overlook subtle expression patterns in complex tissues. We present Spatial Gradient Screening, an algorithm which facilitates the supervised detection of histology-associated gene expression patterns without prior data grouping. Utilizing spatial transcriptomic data along with single-cell deconvolution from injured mouse cortex, and TCR-seq data from brain tumors, we compare our methodology to standard differential gene expression analysis. Our findings illustrate both the advantages and limitations of cluster-free detection of gene expression, offering more profound insights into the spatial architecture of transcriptomes. The algorithm is embedded in SPATA2, an open-source framework written in R, which provides a comprehensive set of tools for investigating gene expression within tissue.


Assuntos
Algoritmos , Perfilação da Expressão Gênica , Transcriptoma , Animais , Camundongos , Perfilação da Expressão Gênica/métodos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Humanos , Análise de Célula Única/métodos
3.
Nat Biomed Eng ; 8(6): 672-688, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38987630

RESUMO

The most widely used fluorophore in glioma-resection surgery, 5-aminolevulinic acid (5-ALA), is thought to cause the selective accumulation of fluorescent protoporphyrin IX (PpIX) in tumour cells. Here we show that the clinical detection of PpIX can be improved via a microscope that performs paired stimulated Raman histology and two-photon excitation fluorescence microscopy (TPEF). We validated the technique in fresh tumour specimens from 115 patients with high-grade gliomas across four medical institutions. We found a weak negative correlation between tissue cellularity and the fluorescence intensity of PpIX across all imaged specimens. Semi-supervised clustering of the TPEF images revealed five distinct patterns of PpIX fluorescence, and spatial transcriptomic analyses of the imaged tissue showed that myeloid cells predominate in areas where PpIX accumulates in the intracellular space. Further analysis of external spatially resolved metabolomics, transcriptomics and RNA-sequencing datasets from glioblastoma specimens confirmed that myeloid cells preferentially accumulate and metabolize PpIX. Our findings question 5-ALA-induced fluorescence in glioma cells and show how 5-ALA and TPEF imaging can provide a window into the immune microenvironment of gliomas.


Assuntos
Neoplasias Encefálicas , Glioma , Protoporfirinas , Análise Espectral Raman , Protoporfirinas/metabolismo , Humanos , Glioma/patologia , Glioma/metabolismo , Glioma/cirurgia , Glioma/diagnóstico por imagem , Análise Espectral Raman/métodos , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Microscopia de Fluorescência/métodos , Ácido Aminolevulínico/metabolismo , Feminino , Masculino
4.
J Neurooncol ; 169(2): 329-340, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38900237

RESUMO

PURPOSE: Mesenchymal stromal cells (MSCs) within the glioblastoma microenvironment have been shown to promote tumor progression. Tumor Treating Fields (TTFields) are alternating electric fields with low intensity and intermediate frequency that exhibit anti-tumorigenic effects. While the effects of TTFields on glioblastoma cells have been studied previously, nothing is known about the influence of TTFields on MSCs. METHODS: Single-cell RNA sequencing and immunofluorescence staining were employed to identify glioblastoma-associated MSCs in patient samples. Proliferation and clonogenic survival of human bone marrow-derived MSCs were assessed after TTFields in vitro. MSC' characteristic surface marker expression was determined using flow cytometry, while multi-lineage differentiation potential was examined with immunohistochemistry. Apoptosis was quantified based on caspase-3 and annexin-V/7-AAD levels in flow cytometry, and senescence was assessed with ß-galactosidase staining. MSCs' migratory potential was evaluated with Boyden chamber assays. RESULTS: Single-cell RNA sequencing and immunofluorescence showed the presence of glioblastoma-associated MSCs in patient samples. TTFields significantly reduced proliferation and clonogenic survival of human bone marrow-derived MSCs by up to 60% and 90%, respectively. While the characteristic surface marker expression and differentiation capacity were intact after TTFields, treatment resulted in increased apoptosis and senescence. Furthermore, TTFields significantly reduced MSCs' migratory capacity. CONCLUSION: We could demonstrate the presence of tumor-associated MSCs in glioblastoma patients, providing a rationale to study the impact of TTFields on MSCs. TTFields considerably increase apoptosis and senescence in MSCs, resulting in impaired survival and migration. The results provide a basis for further analyses on the role of MSCs in glioblastoma patients receiving TTFields.


Assuntos
Apoptose , Neoplasias Encefálicas , Diferenciação Celular , Proliferação de Células , Glioblastoma , Células-Tronco Mesenquimais , Humanos , Células-Tronco Mesenquimais/fisiologia , Glioblastoma/terapia , Glioblastoma/patologia , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/patologia , Terapia por Estimulação Elétrica/métodos , Microambiente Tumoral , Movimento Celular
5.
Clin Neuroradiol ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918242

RESUMO

PURPOSE: After vertical parasagittal hemispherotomy a restricted diffusion is often seen ipsilaterally and even distant from the adjacent resection margin. This retrospective cohort study analyses the anatomic site and the time course of the diffusion restriction after vertical parasagittal hemispherotomy. METHODS: Fifty-nine patients were included into this study, all of them having had one pre-operative and at least one post-operative MRI, including diffusion imaging at b­values of 0 and 1000 s/mm2 with a calculated ADC. RESULTS: Diffusion restriction occurred exclusively on the operated site in all patients. In the basal ganglia, diffusion restriction was present in 37 of 38 patients at the first postoperative day with a duration of 38 days. In the midbrain, the posterior limb of the internal capsule and the thalamus, a restricted diffusion became postoperatively prominent at day 9 in all three localizations, with a duration of 36, 34 and 36 days, respectively. The incidence of thalamic lesions was lower if a preoperative damage had occurred. CONCLUSION: The restricted diffusion in the basal ganglia resembles direct effects of the operation at its edges, whereas the later appearing diffusion restriction in the midbrain and the posterior limb of the internal capsule rather belong to a degeneration of the descending fibers being transected by the hemispherotomy in the sense of a Wallerian degeneration. The presence of preoperative hemispheric lesions influences the development of diffusion restriction at subacute fiber degeneration.

6.
Cancer Cell ; 42(6): 934-936, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38861929

RESUMO

In this issue of Cancer Cell, Zhong et al. explore the dual role of TREM2 in glioblastoma-associated myeloid cells, demonstrating its function in promoting inflammation at the tumor-neural interface and suppression within the tumor core, influenced by the local microenvironment. These findings open up promising prospects for advancements in neuro-oncological immunotherapy.


Assuntos
Glioblastoma , Glicoproteínas de Membrana , Células Mieloides , Microambiente Tumoral , Humanos , Microambiente Tumoral/imunologia , Células Mieloides/imunologia , Células Mieloides/patologia , Células Mieloides/metabolismo , Glicoproteínas de Membrana/metabolismo , Glioblastoma/patologia , Glioblastoma/imunologia , Glioblastoma/metabolismo , Receptores Imunológicos/metabolismo , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/metabolismo , Neurônios/metabolismo , Neurônios/patologia
7.
PLoS Biol ; 22(5): e3002640, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38814900

RESUMO

Glioblastoma, the most aggressive and prevalent form of primary brain tumor, is characterized by rapid growth, diffuse infiltration, and resistance to therapies. Intrinsic heterogeneity and cellular plasticity contribute to its rapid progression under therapy; therefore, there is a need to fully understand these tumors at a single-cell level. Over the past decade, single-cell transcriptomics has enabled the molecular characterization of individual cells within glioblastomas, providing previously unattainable insights into the genetic and molecular features that drive tumorigenesis, disease progression, and therapy resistance. However, despite advances in single-cell technologies, challenges such as high costs, complex data analysis and interpretation, and difficulties in translating findings into clinical practice persist. As single-cell technologies are developed further, more insights into the cellular and molecular heterogeneity of glioblastomas are expected, which will help guide the development of personalized and effective therapies, thereby improving prognosis and quality of life for patients.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Análise de Célula Única , Humanos , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/terapia , Análise de Célula Única/métodos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Transcriptoma , Animais
8.
Neuro Oncol ; 26(8): 1479-1493, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38507506

RESUMO

BACKGROUND: H3 K27M-mutated gliomas were first described as a new grade 4 entity in the 2016 World Health Organization classification. Current studies have focused on its typical appearance in children and young adults, increasing the need to better understand the prognostic factors and impact of surgery on adults. Here, we report a multicentric study of this entity in adults. METHODS: We included molecularly confirmed H3 K27M-mutated glioma cases in patients ≥ 18 years diagnosed between 2016 and 2022. Clinical, radiological, and surgical features were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Among 70 patients with a mean age of 36.1 years, the median overall survival (OS) was 13.6 ±â€…14 months. Gross-total resection was achieved in 14.3% of patients, whereas 30% had a subtotal resection and 54.3% a biopsy. Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location in the mesencephalon/metencephalon showed a significantly longer OS (8.7 vs. 25.0 months, P = .007). Preoperative Karnofsky-Performance Score (KPS) ≤ 80 showed a reduced OS (4.2 vs. 18 months, P = .02). Furthermore, ATRX loss, found in 25.7%, was independently associated with an increased OS (31 vs. 8.3 months, P = .0029). Notably, patients undergoing resection showed no survival benefit over biopsy (12 vs. 11 months, P = .4006). CONCLUSIONS: The present study describes surgical features of H3 K27M-mutated glioma in adulthood in a large multicentric study. Our data reveal that ATRX status, location and KPS significantly impact OS in H3 K27M-mutated glioma. Importantly, our dataset indicates that resection does not offer a survival advantage over biopsy.


Assuntos
Neoplasias Encefálicas , Glioma , Histonas , Mutação , Proteína Nuclear Ligada ao X , Humanos , Masculino , Glioma/cirurgia , Glioma/genética , Glioma/patologia , Glioma/mortalidade , Feminino , Proteína Nuclear Ligada ao X/genética , Adulto , Prognóstico , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/mortalidade , Histonas/genética , Pessoa de Meia-Idade , Adulto Jovem , Taxa de Sobrevida , Seguimentos , Biomarcadores Tumorais/genética , Idoso , Adolescente , Estudos Retrospectivos
9.
Nervenarzt ; 95(2): 104-110, 2024 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-38180512

RESUMO

BACKGROUND: Primary brain tumors and metastases in the central nervous system (CNS) are characterized by their unique microenvironment, which interacts with neuronal structures and influences structural and adaptive immunity. OBJECTIVE: How significant are various tumor-host interactions from a prognostic and therapeutic perspective? MATERIAL AND METHOD: A literature search was carried out for relevant articles on the topic: microenvironment glioblastoma or metastasis through PubMed and Medline. RESULTS: Modern high-throughput methods, such as spatial and single-cell resolution molecular characterization of tumors and their microenvironment enable a detailed mapping of changes and adaptation of individual cells within the microenvironment of tumors; however, treatment approaches based on altered tumor-host cell interactions, such as immune modeling, cell-based treatment methods or checkpoint inhibition have so far not shown any significant advantages for survival. CONCLUSION: A deeper understanding of the complex immune landscape and the microenvironment of metastases of the CNS and intracerebral tumors is essential to optimize future treatment strategies.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Neoplasias Encefálicas/terapia , Glioblastoma/patologia , Glioblastoma/terapia , Prognóstico , Sistema Nervoso Central , Comunicação Celular , Microambiente Tumoral
10.
Neuro Oncol ; 26(4): 625-639, 2024 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-37936324

RESUMO

BACKGROUND: Glioblastomas have highly infiltrative growth patterns that contribute to recurrence and poor survival. Despite infiltration being a critical therapeutic target, no clinically useful therapies exist that counter glioblastoma invasion. Here, we report that inhibition of ataxia telangiectasia and Rad 3 related kinase (ATR) reduces invasion of glioblastoma cells through dysregulation of cytoskeletal networks and subsequent integrin trafficking. METHODS: Glioblastoma motility and invasion were assessed in vitro and in vivo in response to ATR inhibition (ATRi) and ATR overexpression using time-lapse microscopy, two orthotopic glioblastoma models, and intravital imaging. Disruption to cytoskeleton networks and endocytic processing were investigated via high-throughput, super-resolution and intravital imaging. RESULTS: High ATR expression was associated with significantly poorer survival in clinical datasets while histological, protein expression, and spatial transcriptomics using glioblastoma tumor specimens revealed higher ATR expression at infiltrative margins. Pharmacological inhibition with two different compounds and RNAi targeting of ATR opposed the invasion of glioblastoma, whereas overexpression of ATR drove migration. Subsequent investigation revealed that cytoskeletal dysregulation reduced macropinocytotic internalization of integrins at growth-cone-like structures, resulting in a tumor microtube retraction defect. The biological relevance and translational potential of these findings were confirmed using two orthotopic in vivo models of glioblastoma and intravital imaging. CONCLUSIONS: We demonstrate a novel role for ATR in determining invasion in glioblastoma cells and propose that pharmacological targeting of ATR could have far-reaching clinical benefits beyond radiosensitization.


Assuntos
Glioblastoma , Humanos , Glioblastoma/patologia , Integrinas/metabolismo , Linhagem Celular Tumoral , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Invasividade Neoplásica , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo
11.
Nat Med ; 30(1): 186-198, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38123840

RESUMO

The innate immune compartment of the human central nervous system (CNS) is highly diverse and includes several immune-cell populations such as macrophages that are frequent in the brain parenchyma (microglia) and less numerous at the brain interfaces as CNS-associated macrophages (CAMs). Due to their scantiness and particular location, little is known about the presence of temporally and spatially restricted CAM subclasses during development, health and perturbation. Here we combined single-cell RNA sequencing, time-of-flight mass cytometry and single-cell spatial transcriptomics with fate mapping and advanced immunohistochemistry to comprehensively characterize the immune system at human CNS interfaces with over 356,000 analyzed transcriptomes from 102 individuals. We also provide a comprehensive analysis of resident and engrafted myeloid cells in the brains of 15 individuals with peripheral blood stem cell transplantation, revealing compartment-specific engraftment rates across different CNS interfaces. Integrated multiomic and high-resolution spatial transcriptome analysis of anatomically dissected glioblastoma samples shows regionally distinct myeloid cell-type distributions driven by hypoxia. Notably, the glioblastoma-associated hypoxia response was distinct from the physiological hypoxia response in fetal microglia and CAMs. Our results highlight myeloid diversity at the interfaces of the human CNS with the periphery and provide insights into the complexities of the human brain's immune system.


Assuntos
Glioblastoma , Humanos , Multiômica , Sistema Nervoso Central , Microglia , Imunidade Inata/genética , Hipóxia
12.
Nat Commun ; 14(1): 7432, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973846

RESUMO

Spatial resolution of the T cell repertoire is essential for deciphering cancer-associated immune dysfunction. Current spatially resolved transcriptomic technologies are unable to directly annotate T cell receptors (TCR). We present spatially resolved T cell receptor sequencing (SPTCR-seq), which integrates optimized target enrichment and long-read sequencing for highly sensitive TCR sequencing. The SPTCR computational pipeline achieves yield and coverage per TCR comparable to alternative single-cell TCR technologies. Our comparison of PCR-based and SPTCR-seq methods underscores SPTCR-seq's superior ability to reconstruct the entire TCR architecture, including V, D, J regions and the complementarity-determining region 3 (CDR3). Employing SPTCR-seq, we assess local T cell diversity and clonal expansion across spatially discrete niches. Exploration of the reciprocal interaction of the tumor microenvironmental and T cells discloses the critical involvement of NK and B cells in T cell exhaustion. Integrating spatially resolved omics and TCR sequencing provides as a robust tool for exploring T cell dysfunction in cancers and beyond.


Assuntos
Receptores de Antígenos de Linfócitos T , Linfócitos T , Receptores de Antígenos de Linfócitos T/genética , Regiões Determinantes de Complementaridade/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Perfilação da Expressão Gênica , Receptores de Antígenos de Linfócitos T alfa-beta/genética
13.
bioRxiv ; 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37961527

RESUMO

Gliomas are incurable malignancies notable for an immunosuppressive microenvironment with abundant myeloid cells whose immunomodulatory properties remain poorly defined. Here, utilizing scRNA-seq data for 183,062 myeloid cells from 85 human tumors, we discover that nearly all glioma-associated myeloid cells express at least one of four immunomodulatory activity programs: Scavenger Immunosuppressive, C1Q Immunosuppressive, CXCR4 Inflammatory, and IL1B Inflammatory. All four programs are present in IDH1 mutant and wild-type gliomas and are expressed in macrophages, monocytes, and microglia whether of blood or resident myeloid cell origins. Integrating our scRNA-seq data with mitochondrial DNA-based lineage tracing, spatial transcriptomics, and organoid explant systems that model peripheral monocyte infiltration, we show that these programs are driven by microenvironmental cues and therapies rather than myeloid cell type, origin, or mutation status. The C1Q Immunosuppressive program is driven by routinely administered dexamethasone. The Scavenger Immunosuppressive program includes ligands with established roles in T-cell suppression, is induced in hypoxic regions, and is associated with immunotherapy resistance. Both immunosuppressive programs are less prevalent in lower-grade gliomas, which are instead enriched for the CXCR4 Inflammatory program. Our study provides a framework to understand immunomodulatory myeloid cells in glioma, and a foundation to develop more effective immunotherapies.

14.
Mol Cell ; 83(23): 4334-4351.e7, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37979586

RESUMO

Growth factor receptors rank among the most important oncogenic pathways, but pharmacologic inhibitors often demonstrate limited benefit as monotherapy. Here, we show that epidermal growth factor receptor (EGFR) signaling repressed N6-methyladenosine (m6A) levels in glioblastoma stem cells (GSCs), whereas genetic or pharmacologic EGFR targeting elevated m6A levels. Activated EGFR induced non-receptor tyrosine kinase SRC to phosphorylate the m6A demethylase, AlkB homolog 5 (ALKBH5), thereby inhibiting chromosomal maintenance 1 (CRM1)-mediated nuclear export of ALKBH5 to permit sustained mRNA m6A demethylation in the nucleus. ALKBH5 critically regulated ferroptosis through m6A modulation and YTH N6-methyladenosine RNA binding protein (YTHDF2)-mediated decay of the glutamate-cysteine ligase modifier subunit (GCLM). Pharmacologic targeting of ALKBH5 augmented the anti-tumor efficacy of EGFR and GCLM inhibitors, supporting an EGFR-ALKBH5-GCLM oncogenic axis. Collectively, EGFR reprograms the epitranscriptomic landscape through nuclear retention of the ALKBH5 demethylase to protect against ferroptosis, offering therapeutic paradigms for the treatment of lethal cancers.


Assuntos
Homólogo AlkB 5 da RNA Desmetilase , Receptores ErbB , Ferroptose , Glioblastoma , Humanos , Adenosina/metabolismo , Homólogo AlkB 5 da RNA Desmetilase/genética , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Receptores ErbB/genética , Ferroptose/genética , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , RNA Mensageiro/genética
15.
Nat Commun ; 14(1): 4122, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37433817

RESUMO

Intra-tumoral heterogeneity and cell-state plasticity are key drivers for the therapeutic resistance of glioblastoma. Here, we investigate the association between spatial cellular organization and glioblastoma prognosis. Leveraging single-cell RNA-seq and spatial transcriptomics data, we develop a deep learning model to predict transcriptional subtypes of glioblastoma cells from histology images. Employing this model, we phenotypically analyze 40 million tissue spots from 410 patients and identify consistent associations between tumor architecture and prognosis across two independent cohorts. Patients with poor prognosis exhibit higher proportions of tumor cells expressing a hypoxia-induced transcriptional program. Furthermore, a clustering pattern of astrocyte-like tumor cells is associated with worse prognosis, while dispersion and connection of the astrocytes with other transcriptional subtypes correlate with decreased risk. To validate these results, we develop a separate deep learning model that utilizes histology images to predict prognosis. Applying this model to spatial transcriptomics data reveal survival-associated regional gene expression programs. Overall, our study presents a scalable approach to unravel the transcriptional heterogeneity of glioblastoma and establishes a critical connection between spatial cellular architecture and clinical outcomes.


Assuntos
Glioblastoma , Humanos , Glioblastoma/genética , Astrócitos , Plasticidade Celular , Análise por Conglomerados , Perfilação da Expressão Gênica
16.
STAR Protoc ; 4(3): 102383, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37393609

RESUMO

Single-cell RNA-sequencing (scRNA-seq) is becoming a ubiquitous method in profiling the cellular transcriptomes of both malignant and non-malignant cells from the human brain. Here, we present a protocol to isolate viable tumor cells from human ex vivo glioblastoma cultures for single-cell transcriptomic analysis. We describe steps including surgical tissue collection, sectioning, culturing, primary tumor cells inoculation, growth tracking, fluorescence-based cell sorting, and population-enriched scRNA-seq. This comprehensive methodology empowers in-depth understanding of brain tumor biology at the single-cell level. For complete details on the use and execution of this protocol, please refer to Ravi et al.1.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/genética , Perfilação da Expressão Gênica , Neoplasias Encefálicas/genética , Encéfalo , Transcriptoma/genética
17.
Neuro Oncol ; 25(11): 1963-1975, 2023 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-37288604

RESUMO

BACKGROUND: In glioblastoma (GBM), the effects of altered glycocalyx are largely unexplored. The terminal moiety of cell coating glycans, sialic acid, is of paramount importance for cell-cell contacts. However, sialic acid turnover in gliomas and its impact on tumor networks remain unknown. METHODS: We streamlined an experimental setup using organotypic human brain slice cultures as a framework for exploring brain glycobiology, including metabolic labeling of sialic acid moieties and quantification of glycocalyx changes. By live, 2-photon and high-resolution microscopy we have examined morphological and functional effects of altered sialic acid metabolism in GBM. By calcium imaging we investigated the effects of the altered glycocalyx on a functional level of GBM networks. RESULTS: The visualization and quantitative analysis of newly synthesized sialic acids revealed a high rate of de novo sialylation in GBM cells. Sialyltrasferases and sialidases were highly expressed in GBM, indicating that significant turnover of sialic acids is involved in GBM pathology. Inhibition of either sialic acid biosynthesis or desialylation affected the pattern of tumor growth and lead to the alterations in the connectivity of glioblastoma cells network. CONCLUSIONS: Our results indicate that sialic acid is essential for the establishment of GBM tumor and its cellular network. They highlight the importance of sialic acid for glioblastoma pathology and suggest that dynamics of sialylation have the potential to be targeted therapeutically.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/patologia , Ácido N-Acetilneuramínico/metabolismo , Ácidos Siálicos/metabolismo , Transdução de Sinais , Linhagem Celular Tumoral
18.
J Clin Invest ; 133(5)2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36856115

RESUMO

Cancer-associated fibroblasts (CAFs) were presumed absent in glioblastoma given the lack of brain fibroblasts. Serial trypsinization of glioblastoma specimens yielded cells with CAF morphology and single-cell transcriptomic profiles based on their lack of copy number variations (CNVs) and elevated individual cell CAF probability scores derived from the expression of 9 CAF markers and absence of 5 markers from non-CAF stromal cells sharing features with CAFs. Cells without CNVs and with high CAF probability scores were identified in single-cell RNA-Seq of 12 patient glioblastomas. Pseudotime reconstruction revealed that immature CAFs evolved into subtypes, with mature CAFs expressing actin alpha 2, smooth muscle (ACTA2). Spatial transcriptomics from 16 patient glioblastomas confirmed CAF proximity to mesenchymal glioblastoma stem cells (GSCs), endothelial cells, and M2 macrophages. CAFs were chemotactically attracted to GSCs, and CAFs enriched GSCs. We created a resource of inferred crosstalk by mapping expression of receptors to their cognate ligands, identifying PDGF and TGF-ß as mediators of GSC effects on CAFs and osteopontin and HGF as mediators of CAF-induced GSC enrichment. CAFs induced M2 macrophage polarization by producing the extra domain A (EDA) fibronectin variant that binds macrophage TLR4. Supplementing GSC-derived xenografts with CAFs enhanced in vivo tumor growth. These findings are among the first to identify glioblastoma CAFs and their GSC interactions, making them an intriguing target.


Assuntos
Fibroblastos Associados a Câncer , Glioblastoma , Humanos , Glioblastoma/genética , Transcriptoma , Variações do Número de Cópias de DNA , Células Endoteliais , Análise de Sequência de RNA
19.
Neurosurgery ; 92(5): 1052-1057, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36700700

RESUMO

BACKGROUND: Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality and poor disability outcome. Data on quality of life (QoL) among survivors are scarce because patients with poor-grade aSAH are underrepresented in clinical studies reporting on QoL after aSAH. OBJECTIVE: To provide prospective QoL data on survivors of poor-grade aSAH to aid clinical decision making and counseling of relatives. METHODS: The herniation World Federation of Neurosurgical Societies scale study was a prospective observational multicenter study in patients with poor-grade (World Federation of Neurosurgical Societies grades 4 & 5) aSAH. We collected data during a structured telephone interview 6 and 12 months after ictus. QoL was measured using the EuroQoL - 5 Dimensions - 3 Levels (EQ-5D-3L) questionnaire, with 0 representing a health state equivalent to death and 1 to perfect health. Disability outcome for favorable and unfavorable outcomes was measured with the modified Rankin Scale. RESULTS: Two hundred-fifty patients were enrolled, of whom 237 were included in the analysis after 6 months and 223 after 12 months. After 6 months, 118 (49.8%) patients were alive, and after 12 months, 104 (46.6%) patients were alive. Of those, 95 (80.5%) and 89 (85.6%) reached a favorable outcome with mean EQ-5D-3L index values of 0.85 (±0.18) and 0.86 (±0.18). After 6 and 12 months, 23 (19.5%) and 15 (14.4%) of those alive had an unfavorable outcome with mean EQ-5D-3L index values of 0.27 (±0.25) and 0.19 (±0.14). CONCLUSION: Despite high initial mortality, the proportion of poor-grade aSAH survivors with good QoL is reasonably large. Only a minority of survivors reports poor QoL and requires permanent care.


Assuntos
Acidente Vascular Cerebral , Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/cirurgia , Resultado do Tratamento , Qualidade de Vida , Estudos Prospectivos , Acidente Vascular Cerebral/complicações , Estudos Retrospectivos
20.
Life Sci Alliance ; 6(1)2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36414381

RESUMO

Enhanced fatty acid synthesis is a hallmark of tumors, including glioblastoma. SREBF1/2 regulate the expression of enzymes involved in fatty acid and cholesterol synthesis. Yet, little is known about the precise mechanism regulating SREBP gene expression in glioblastoma. Here, we show that a novel interaction between the co-activator/co-repressor CTBP and the tumor suppressor ZBTB18 regulates the expression of SREBP genes. In line with our findings, metabolic assays and glucose tracing analysis confirm the reduction in several phospholipid species upon ZBTB18 expression. Our study identifies CTBP1/2 and LSD1 as co-activators of SREBP genes and indicates that the functional activity of the CTBP-LSD1 complex is altered by ZBTB18. ZBTB18 binding to the SREBP gene promoters is associated with reduced LSD1 demethylase activity of H3K4me2 and H3K9me2 marks. Concomitantly, the interaction between LSD1, CTBP, and ZNF217 is increased, suggesting that ZBTB18 promotes LSD1 scaffolding function. Our results outline a new epigenetic mechanism enrolled by ZBTB18 and its co-factors to regulate fatty acid synthesis that could be targeted to treat glioblastoma patients.


Assuntos
Glioblastoma , Humanos , Ácidos Graxos , Glioblastoma/genética , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Lipídeos , Proteína de Ligação a Elemento Regulador de Esterol 1/genética
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