RESUMO

MYC promotes tumor growth through multiple mechanisms. Here, we show that, in human glioblastomas, the variant MYC transcript encodes a 114-amino acid peptide, MYC pre-mRNA encoded protein (MPEP), from the upstream open reading frame (uORF) MPEP. Secreted MPEP promotes patient-derived xenograft tumor growth in vivo, independent of MYC through direct binding, and activation of tropomyosin receptor kinase B (TRKB), which induces downstream AKT-mTOR signaling. Targeting MPEP through genetic ablation reduced growth of patient-derived 4121 and 3691 glioblastoma stem cells. Administration of an MPEP-neutralizing antibody in combination with a small-molecule TRKB inhibitor reduced glioblastoma growth in patient-derived xenograft tumor-bearing mice. The overexpression of MPEP in surgical glioblastoma specimens predicted a poor prognosis, supporting its clinical relevance. In summary, our results demonstrate that tumor-specific translation of a MYC-associated uORF promotes glioblastoma growth, suggesting a new therapeutic strategy for glioblastoma.

Assuntos

Glioblastoma , Fases de Leitura Aberta , Proteínas Proto-Oncogênicas c-myc , Receptor trkB , Glioblastoma/patologia , Glioblastoma/metabolismo , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Animais , Humanos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fases de Leitura Aberta/genética , Camundongos , Linhagem Celular Tumoral , Receptor trkB/metabolismo , Proliferação de Células/efeitos dos fármacos , Ligação Proteica , Transdução de Sinais , Peptídeos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Regulação Neoplásica da Expressão Gênica

RESUMO

The mechanisms underlying stimuli-induced dynamic structural remodeling of RNAs for the maintenance of cellular physiological function and survival remain unclear. Here, we showed that in MGMT promoter-methylated glioblastoma (GBM), the RNA helicase DEAD-box helicase 46 (DDX46) is phosphorylated by temozolomide (TMZ)-activated checkpoint kinase 1 (CHK1), resulting in a dense-to-loose conformational change and an increase in DDX46 helicase activity. DDX46-mediated tertiary structural remodeling of LINC01956 exposes the binding motifs of LINC01956 to the 3' untranslated region of O6-methylguanine DNA methyltransferase (MGMT). This accelerates recruitment of MGMT mRNA to the RNA export machinery and transportation of MGMT mRNA from the nucleus to the cytoplasm, leading to increased MGMT abundance and TMZ resistance. Using patient-derived xenograft (PDX) and tumor organoid models, we found that treatment with the CHK1 inhibitor SRA737abolishes TMZ-induced structural remodeling of LINC01956 and subsequent MGMT up-regulation, resensitizing TMZ-resistant MGMT promoter-methylated GBM to TMZ. In conclusion, these findings highlight a mechanism underlying temozolomide-induced RNA structural remodeling and may represent a potential therapeutic strategy for patients with TMZ-resistant MGMT promoter-methylated GBM.

Assuntos

RNA Helicases DEAD-box , Metilases de Modificação do DNA , Resistencia a Medicamentos Antineoplásicos , Glioblastoma , RNA Longo não Codificante , Temozolomida , Proteínas Supressoras de Tumor , Glioblastoma/genética , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Glioblastoma/metabolismo , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Humanos , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Animais , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas Supressoras de Tumor/genética , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/genética , Metilases de Modificação do DNA/metabolismo , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Enzimas Reparadoras do DNA/genética , Regiões Promotoras Genéticas/genética , Metilação de DNA/genética , Metilação de DNA/efeitos dos fármacos , Quinase 1 do Ponto de Checagem/metabolismo , Quinase 1 do Ponto de Checagem/genética , Linhagem Celular Tumoral , Camundongos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Fosforilação/efeitos dos fármacos

RESUMO

Objective. Carboxypeptidase E (CPE) plays an important role in the biosynthesis of neurotransmitters and peptide hormones including insulin. It also promotes cell proliferation, survival, and invasion of tumor cells. The endoplasmic reticulum stress, hypoxia, and nutrient supply are significant factors of malignant tumor growth including glioblastoma. There are data indicating that the knockdown of the endoplasmic reticulum to nucleus signaling 1 (ERN1) suppressed glioblastoma cell proliferation and increased invasiveness of these cells. The present study aims to investigate the regulation of the CPE gene in U87MG glioblastoma cells by ERN1 knockdown, hypoxia, and glucose or glutamine deprivations with the intent to reveal the role of ERN1 signaling in the regulation of this gene expression and function in tumorigenesis. Methods. Human glioblastoma cells U87MG (transfected by an empty vector; control) and ERN1 knockdown cells with inhibited ERN1 endoribonuclease and protein kinase (dnERN1) or only ERN1 endoribonuclease (dnrERN1) were used. Hypoxia was introduced by dimethyloxalylglycine; for glucose and glutamine deprivations, the cells were cultured in DMEM medium without glucose or glutamine for 16 h, respectively. The expression level of the CPE gene was studied by quantitative RT-PCR and normalized to ACTB. Results. It was found that inhibition of endoribonuclease and protein kinase activities of ERN1 led to a strong up-regulation of CPE gene expression in glioblastoma cells. The expression of this gene also increased in glioblastoma cells after silencing ERN1. At the same time, the expression of this gene did not significantly change in cells with inhibited ERN1 endoribonuclease only. The expression of the CPE gene was resistant to hypoxia in control U87MG cells, but increased in cells with ERN1 knockdown. The expression of this gene was up-regulated under glutamine deprivation in control glioblastoma cells, but decreased upon ERN1 knockdown. However, glucose deprivation decreased the expression of CPE gene in both types of used cells, but ERN1 inhibition enhanced this effect. Conclusion. The results of the present study demonstrate that inhibition of ERN1 strongly up-regulated the expression of pro-oncogenic CPE gene through protein kinase activity of ERN1 and that increased CPE gene expression possibly participates in ERN1 knockdown-mediated invasiveness of glioblastoma cells.

Assuntos

Carboxipeptidase H , Estresse do Retículo Endoplasmático , Endorribonucleases , Regulação Neoplásica da Expressão Gênica , Glioblastoma , Proteínas Serina-Treonina Quinases , Humanos , Glioblastoma/metabolismo , Glioblastoma/genética , Glioblastoma/patologia , Carboxipeptidase H/metabolismo , Carboxipeptidase H/genética , Linhagem Celular Tumoral , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/metabolismo , Endorribonucleases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Glucose/metabolismo , Técnicas de Silenciamento de Genes , Hipóxia Celular/fisiologia , Transdução de Sinais/fisiologia

RESUMO

CD2-associated protein (CD2AP) is a scaffolding/adaptive protein that regulates intercellular adhesion and multiple signaling pathways. Although emerging evidence suggests that CD2AP is associated with several malignant tumors, there is no study investigating the expression and biological significance of CD2AP in glioblastoma multiforme (GBM). Here by studying public datasets, we found that CD2AP expression was significantly elevated in GBM and that glioma patients with increased CD2AP expression had a worse prognosis. We also confirmed the increase of CD2AP expression in clinical GBM samples and GBM cell lines. CD2AP overexpression in GBM cells promoted their proliferation, colony formation, migration, and invasion in vitro and their tumorigenesis in vivo, and reduced cell apoptosis both at basal levels and in response to temozolomide. While CD2AP knockdown had the opposite effects. Mechanistically, we revealed that CD2AP interacted with TRIM5, an NF-κB modulator. CD2AP overexpression and knockdown increased and decreased TRIM5 levels as well as the NF-κB activity, respectively. Moreover, downregulation of TRIM5 reversed elevated NF-κB activity in GBM cells with CD2AP overexpression; and inhibition of the NF-κB activity attenuated malignant features of GBM cells with CD2AP overexpression. Our findings demonstrate that CD2AP promotes GBM progression through activating TRIM5-mediated NF-κB signaling and that downregulation of CD2AP can attenuate GBM malignancy, suggesting that CD2AP may become a biomarker and the CD2AP-TRIM5-NF-κB axis may become a therapeutic target for GBM.

Assuntos

Proteínas Adaptadoras de Transdução de Sinal , Glioblastoma , NF-kappa B , Transdução de Sinais , Glioblastoma/patologia , Glioblastoma/metabolismo , Glioblastoma/genética , Humanos , NF-kappa B/metabolismo , Animais , Linhagem Celular Tumoral , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Progressão da Doença , Proliferação de Células , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/genética , Camundongos , Camundongos Nus , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Proteínas com Motivo Tripartido/metabolismo , Proteínas com Motivo Tripartido/genética , Apoptose , Masculino , Feminino , Proteínas do Citoesqueleto

RESUMO

Glycolytic metabolic reprogramming in cancer is regulated by both cancer intrinsic variations like isocitrate dehydrogenase 1 (IDH1) status and non-cancerous microenvironment components like tumor associated macrophages (TAMs). However, the detailed mechanism remains elusive. Here, we identify hexosaminidase B (HEXB) as a key regulator for glycolysis in glioblastoma (GBM). HEXB intercellularly manipulates TAMs to promote glycolysis in GBM cells, while intrinsically enhancing cancer cell glycolysis. Mechanistically, HEXB elevation augments tumor HIF1α protein stability through activating ITGB1/ILK/YAP1; Subsequently, HIF1α promotes HEXB and multiple glycolytic gene transcription in GBM cells. Genetic ablation and pharmacological inhibition of HEXB elicits substantial therapeutic effects in preclinical GBM models, while targeting HEXB doesn't induce significant reduction in IDH1 mutant glioma and inhibiting IDH1 mutation-derived 2-hydroxyglutaric acid (2-HG) significantly restores HEXB expression in glioma cells. Our work highlights a HEXB driven TAMs-associated glycolysis-promoting network in GBM and provides clues for developing more effective therapies against it.

Assuntos

Neoplasias Encefálicas , Carcinogênese , Glioblastoma , Glicólise , Subunidade alfa do Fator 1 Induzível por Hipóxia , Isocitrato Desidrogenase , beta-N-Acetil-Hexosaminidases , Humanos , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Linhagem Celular Tumoral , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Carcinogênese/genética , Camundongos , beta-N-Acetil-Hexosaminidases/metabolismo , beta-N-Acetil-Hexosaminidases/genética , Microambiente Tumoral/imunologia , Regulação Neoplásica da Expressão Gênica , Macrófagos Associados a Tumor/metabolismo , Macrófagos Associados a Tumor/imunologia , Integrina beta1/metabolismo , Integrina beta1/genética , Glutaratos/metabolismo , Mutação , Proteínas de Sinalização YAP/metabolismo

RESUMO

We have previously shown that 5-arylaminouracil derivatives can inhibit HIV-1, herpesviruses, mycobacteria, and other pathogens through various mechanisms. The purpose of this study was to evaluate the potential of 5-arylaminouracils and their derivatives against leukemia, neuroblastoma, and glial brain tumors. 5-Aminouracils with various substituents and their 5'-norcabocyclic and ribo derivatives were screened for cytotoxicity against two neuroblastoma cell lines (SH-SY5Y and IMR-32), K-562 lymphoblastic cells, HL-60 promyeoloblastic cells, and low-passage variants of well-differentiated glioblastoma multiforme (GBM5522 and GBM6138). Cytotoxicity assessment by the standard MTT test showed that most of the compounds lack significant toxicity towards the above cells. However, 5-(4-isopropylphenylamine)uracil and 5-(4-tert-butylphenylamine)uracil exhibited a dose-dependent toxic effect towards the GBM6138 cell line with half-maximal inhibitory concentrations (IC50) of 9 and 2.3 µÐœ, respectively. Antitumor activity was for the first time demonstrated for compounds of this type and can serve as a starting point for further research.

Assuntos

Uracila , Humanos , Uracila/análogos & derivados , Uracila/farmacologia , Uracila/toxicidade , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Neuroblastoma/tratamento farmacológico , Neuroblastoma/patologia

RESUMO

BACKGROUND: Glioblastoma is a highly malignant disease with limited treatment options. Ibrutinib, a covalent Bruton tyrosine kinase inhibitor, is an oral agent with manageable side effects used for hematological diseases including Waldenström macroglobulinemia. We present the case of a 69-year-old Caucasian male patient treated with ibrutinib for suspected Bing-Neel syndrome (BNS), which following a biopsy, was reclassified as glioblastoma. CASE PRESENTATION: In December 2018, a 69-year-old Caucasian male patient was diagnosed with Waldenström macroglobulinemia. As the patient was asymptomatic, without bone marrow failure or high M-component count, watchful waiting was initiated. Due to increasing neurological symptoms, the patient, based on magnetic resonance imaging, was diagnosed with Bing-Neel syndrome in May 2019. The patient received different treatments before starting ibrutinib monotherapy in August 2019 due to disease progression, both on magnetic resonance imaging and clinically. The patient remained clinically stable for 7 months. In March 2020, the patient developed headaches, and both magnetic resonance imaging and a biopsy revealed glioblastoma IDH-wildtype. Treatment was changed in line with the new diagnosis, but the patient died at the end of 2020. CONCLUSION: We present a case in which a patient with glioblastoma IDH-wildtype remained clinically stable for 7 months when treated with ibrutinib monotherapy, which is similar to what would be expected for the standard treatment for glioblastoma. To our knowledge, this is the first patient receiving ibrutinib for a glioblastoma IDH-wildtype with a meaningful clinical outcome. Our case may therefore support previous nonclinical findings, indicating a therapeutic value of ibrutinib in patients with glioblastoma and support for further investigation of ibrutinib as a possible treatment for glioblastoma.

Assuntos

Adenina , Glioblastoma , Imageamento por Ressonância Magnética , Piperidinas , Macroglobulinemia de Waldenstrom , Humanos , Adenina/análogos & derivados , Adenina/uso terapêutico , Masculino , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Idoso , Piperidinas/uso terapêutico , Macroglobulinemia de Waldenstrom/tratamento farmacológico , Evolução Fatal , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Inibidores de Proteínas Quinases/uso terapêutico

RESUMO

Significance: Histopathological examination of surgical biopsies, such as in glioma and glioblastoma resection, is hindered in current clinical practice by the long time required for the laboratory analysis and pathological screening, typically taking several days or even weeks to be completed. Aim: We propose here a transportable, high-density, spectral scanning-based hyperspectral imaging (HSI) setup, named HyperProbe1, that can provide in situ, fast biochemical analysis, and mapping of fresh surgical tissue samples, right after excision, and without the need for fixing, staining nor compromising the integrity of the tissue properties. Approach: HyperProbe1 is based on spectral scanning via supercontinuum laser illumination filtered with acousto-optic tunable filters. Such methodology allows the user to select any number and type of wavelength bands in the visible and near-infrared range between 510 and 900 nm (up to a maximum of 79) and to reconstruct 3D hypercubes composed of high-resolution (4 to 5 µ m ), widefield images ( 0.9 × 0.9 mm 2 ) of the surgical samples, where each pixel is associated with a complete spectrum. Results: The HyperProbe1 setup is here presented and characterized. The system is applied to 11 fresh surgical biopsies of glioma from routine patients, including different grades of tumor classification. Quantitative analysis of the composition of the tissue is performed via fast spectral unmixing to reconstruct the mapping of major biomarkers, such as oxy-( HbO 2 ) and deoxyhemoglobin (HHb), as well as cytochrome-c-oxidase (CCO). We also provided a preliminary attempt to infer tumor classification based on differences in composition in the samples, suggesting the possibility of using lipid content and differential CCO concentrations to distinguish between lower and higher-grade gliomas. Conclusions: A proof of concept of the performances of HyperProbe1 for quantitative, biochemical mapping of surgical biopsies is demonstrated, paving the way for improving current post-surgical, histopathological practice via non-destructive, in situ streamlined screening of fresh tissue samples in a matter of minutes after excision.

Assuntos

Neoplasias Encefálicas , Imageamento Hiperespectral , Humanos , Imageamento Hiperespectral/métodos , Biópsia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Glioma/diagnóstico por imagem , Glioma/patologia , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Desenho de Equipamento , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia

RESUMO

Glioblastoma recurrence is currently inevitable despite extensive standard-of-care treatment. In preclinical studies, an alternative strategy of targeting tumor-associated macrophages and microglia through CSF-1R inhibition was previously found to regress established tumors and significantly increase overall survival. However, recurrences developed in ∼50% of mice in long-term studies, which were consistently associated with fibrotic scars. This fibrotic response is observed following multiple anti-glioma therapies in different preclinical models herein and in patient recurrence samples. Multi-omics analyses of the post-treatment tumor microenvironment identified fibrotic areas as pro-tumor survival niches that encapsulated surviving glioma cells, promoted dormancy, and inhibited immune surveillance. The fibrotic treatment response was mediated by perivascular-derived fibroblast-like cells via activation by transforming growth factor ß (TGF-ß) signaling and neuroinflammation. Concordantly, combinatorial inhibition of these pathways inhibited treatment-associated fibrosis, and significantly improved survival in preclinical trials of anti-colony-stimulating factor-1 receptor (CSF-1R) therapy.

Assuntos

Neoplasias Encefálicas , Fibrose , Glioblastoma , Recidiva Local de Neoplasia , Microambiente Tumoral , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Animais , Humanos , Camundongos , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Microambiente Tumoral/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Receptor de Fator Estimulador de Colônias de Macrófagos/metabolismo , Linhagem Celular Tumoral , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Fator de Crescimento Transformador beta/metabolismo

RESUMO

BACKGROUND: Glioblastoma (GBM) stands as the most prevalent and aggressive form of adult gliomas. Despite the implementation of intensive therapeutic approaches involving surgery, radiation, and chemotherapy, Glioblastoma Stem Cells contribute to tumor recurrence and poor prognosis. The induction of Glioblastoma Stem Cells differentiation by manipulating the transcriptional machinery has emerged as a promising strategy for GBM treatment. Here, we explored an innovative approach by investigating the role of the depolarized resting membrane potential (RMP) observed in patient-derived GBM sphereforming cell (GSCs), which allows them to maintain a stemness profile when they reside in the G0 phase of the cell cycle. METHODS: We conducted molecular biology and electrophysiological experiments, both in vitro and in vivo, to examine the functional expression of the voltage-gated sodium channel (Nav) in GSCs, particularly focusing on its cell cycle-dependent functional expression. Nav activity was pharmacologically manipulated, and its effects on GSCs behavior were assessed by live imaging cell cycle analysis, self-renewal assays, and chemosensitivity assays. Mechanistic insights into the role of Nav in regulating GBM stemness were investigated through pathway analysis in vitro and through tumor proliferation assay in vivo. RESULTS: We demonstrated that Nav is functionally expressed by GSCs mainly during the G0 phase of the cell cycle, suggesting its pivotal role in modulating the RMP. The pharmacological blockade of Nav made GBM cells more susceptible to temozolomide (TMZ), a standard drug for this type of tumor, by inducing cell cycle re-entry from G0 phase to G1/S transition. Additionally, inhibition of Nav substantially influenced the self-renewal and multipotency features of GSCs, concomitantly enhancing their degree of differentiation. Finally, our data suggested that Nav positively regulates GBM stemness by depolarizing the RMP and suppressing the ERK signaling pathway. Of note, in vivo proliferation assessment confirmed the increased susceptibility to TMZ following pharmacological blockade of Nav. CONCLUSIONS: This insight positions Nav as a promising prognostic biomarker and therapeutic target for GBM patients, particularly in conjunction with temozolomide treatment.

Assuntos

Diferenciação Celular , Glioblastoma , Células-Tronco Neoplásicas , Canais de Sódio Disparados por Voltagem , Glioblastoma/patologia , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Humanos , Diferenciação Celular/efeitos dos fármacos , Canais de Sódio Disparados por Voltagem/metabolismo , Canais de Sódio Disparados por Voltagem/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Animais , Temozolomida/farmacologia , Linhagem Celular Tumoral , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Proliferação de Células/efeitos dos fármacos , Camundongos

RESUMO

SUMMARY: Imagine if we could simultaneously predict spatial protein expression in tissues from their routine Hematoxylin and Eosin (H&E) stained images, and create tissue images given protein expression profiles thus enabling virtual simulations of how protein expression alterations impact histology in complex diseases like cancer. Such an approach could lead to more informed diagnostic and therapeutic decisions for precision medicine at lower costs and shorter turnaround times, more detailed insights into underlying disease pathology as well as improvement in predictive and generative performance. In this study, we investigate the intricate correlation between protein expressions obtained from Hyperion mass cytometry and histopathological microstructures in conventional H&E stained glioblastoma (GBM) samples, unveiling morphological patterns and cellular-level spatial alterations associated with protein expression changes. To model these complex relationships, we propose a novel generative-predictive framework called Ouroboros for producing H&E images from protein expressions and simultaneously predicting protein expressions from H&E images. Our comprehensive sample-independent validation over 9920 tissue spots from 4 GBM samples encompassing visual image analysis, quantitative analysis, subspace alignment and perturbation experiments shows that the proposed generative-predictive approach offers significant improvements in predicting protein expression from images in comparison to baseline methods as well as accurate generation of virtual GBM sample images. This proof of concept study can contribute to advancing our understanding of histological responses to protein expression perturbations and lays the foundations for further developments in this area. AVAILABILITY AND IMPLEMENTATION: Implementation and associated data for the proposed approach are available at the URL: https://github.com/Srijay/Ouroboros.

Assuntos

Glioblastoma , Humanos , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioblastoma/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Biologia Computacional/métodos

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

RESUMO

Glioblastoma (GBM) represents an aggressive brain tumor, characterized by intra- and inter-tumoral heterogeneity and therapy resistance, leading to unfavourable prognosis. An increasing number of studies pays attention on the regulation of ferroptosis, an iron-dependent cell death, as a strategy to reverse drug resistance in cancer. However, the debate on whether this strategy may have important implications for the treatment of GBM is still ongoing. In the present study, we used ferric ammonium citrate and erastin to evaluate ferroptosis induction effects on two human GBM cell lines, U-251 MG, with proneural characteristics, and T98-G, with a mesenchymal profile. The response to ferroptosis induction was markedly different between cell lines, indeed T98-G cells showed an enhanced antioxidant defence, with increased glutathione levels, as compared to U-251 MG cells. Moreover, using bioinformatic approaches and analysing publicly available datasets from patients' biopsies, we found that GBM with a mesenchymal phenotype showed an up-regulation of several genes involved in antioxidant mechanisms as compared to proneural subtype. Thus, our results suggest that GBM subtypes differently respond to ferroptosis induction, emphasizing the significance of further molecular studies on GBM to better discriminate between various tumor subtypes and progressively move towards personalized therapy.

Assuntos

Antioxidantes , Ferroptose , Glioblastoma , Ferroptose/efeitos dos fármacos , Ferroptose/genética , Humanos , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioblastoma/genética , Linhagem Celular Tumoral , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Regulação Neoplásica da Expressão Gênica , Compostos Férricos/farmacologia , Compostos de Amônio Quaternário/farmacologia , Glutationa/metabolismo , Piperazinas

RESUMO

BACKGROUND: MR perfusion is a standard marker to distinguish progression and therapy-associated changes after surgery and radiochemotherapy for glioblastoma. TRAMs (Treatment Response Assessment Maps) were introduced, which are intended to facilitate the differentiation of vital tumor cells and radiation necrosis by means of late (20-90 min) contrast clearance and enhancement. The differences of MR perfusion and late-enhancement are not fully understood yet. METHODS: We have implemented and established a fully automated creation of rapid wash-out (15-20 min interval) maps in our clinic. We included patients with glioblastoma, CNS lymphoma or brain metastases who underwent our MR protocol with MR perfusion and rapid wash-out between 01/01/2024 and 30/06/2024. Since both wash-out and hyperperfusion are intended to depict the active tumor area, this study involves a quantitative and qualitative comparison of both methods. For this purpose, we volumetrically measured rCBV (relative cerebral blood volume) maps and rapid wash-out maps separately (two raters). Additionally, we rated the agreement between both maps on a Likert scale (0-10). RESULTS: Thirty-two patients were included in the study: 15 with glioblastoma, 7 with CNS lymphomas and 10 with brain metastasis. We calculated 36 rapid wash-out maps (9 initial diagnosis, 27 follow-up). Visual agreement of MR perfusion with rapid wash-out by rating were found in 44 ± 40% for initial diagnosis, and 75 ± 31% for follow-up. We found a strong correlation (Pearson coefficient 0.92, p < 0.001) between the measured volumes of MR perfusion and rapid wash-out. The measured volumes of MR perfusion and rapid wash-out did not differ significantly. Small lesions were often not detected by MR perfusion. Nevertheless, the measured volumes showed no significant differences in this small cohort. CONCLUSIONS: Rapid wash-out calculation is a simple tool that provides new information and, when used in conjunction with MR perfusion, may increase diagnostic accuracy. The method shows promising results, particularly in the evaluation of small lesions.

Assuntos

Neoplasias Encefálicas , Glioblastoma , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/patologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Adulto , Imageamento por Ressonância Magnética/métodos , Linfoma/diagnóstico por imagem , Linfoma/patologia , Angiografia por Ressonância Magnética/métodos , Meios de Contraste

RESUMO

Positronium is abundantly produced within the molecular voids of a patient's body during positron emission tomography (PET). Its properties dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen. Current PET systems record only two annihilation photons and cannot provide information about the positronium lifetime. This study presents the in vivo images of positronium lifetime in a human, for a patient with a glioblastoma brain tumor, by using the dedicated Jagiellonian PET system enabling simultaneous detection of annihilation photons and prompt gamma emitted by a radionuclide. The prompt gamma provides information on the time of positronium formation. The photons from positronium annihilation are used to reconstruct the place and time of its decay. In the presented case study, the determined positron and positronium lifetimes in glioblastoma cells are shorter than those in salivary glands and those in healthy brain tissues, indicating that positronium imaging could be used to diagnose disease in vivo.

Assuntos

Neoplasias Encefálicas , Encéfalo , Glioblastoma , Tomografia por Emissão de Pósitrons , Humanos , Tomografia por Emissão de Pósitrons/métodos , Encéfalo/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia

RESUMO

Background: Glioblastoma (GBM) is characterized by abundant neovascularization as an essential hallmark. Vasculogenic mimicry (VM) is a predominant pattern of GBM neovascularization. However, the biological functions of circRNAs prompting VM formation in GBM remains unclarified. Methods: The circular RNA circCMTM3 was identified through high-throughput sequencing and bioinformatics analysis. The expression of circCMTM3 in exosomes in glioma tissues and cells was verified via RT-qPCR and FISH. In vitro and in vivo assays, such as EdU, MTS, Transwell, and tube formation assays were performed to investigate functional roles of circCMTM3. Meanwhile, in situ tumorigenesis assay were implemented to explore the influences of circCMTM3 on the GBM progression. Additionally, RNA pull-down, RIP, ChIP, and dual-luciferase reporter gene assays were executed to confirm the underlying regulation mechanism of circCMTM3. Results: CircCMTM3, as a novel circular RNA, was packaged into exosomes derived from glioblastoma stem cells (GSCs), which facilitates the phenotypic transition of differentiated glioma cells (DGCs) to VM. Mechanistically, exosomal circCMTM3 is internalized by DGCs and disrupt the ubiquitination degradation of STAT5A and STAT5B by E3 ubiquitin ligase CNOT4. Additionally, through molecular scaffold function of circCMTM3, STAT5A is activated and triggers transcriptional regulation of target genes including the pro-vasculogenic factor CHI3L2 and the RNA-binding protein SRSF1. Subsequently, circCMTM3/STAT5A/SRSF1 positive feedback loop sustainably enhances VM formation and accelerates tumor progression in GBM. Conclusion: Exosomal circCMTM3 possessing growth factor-mimetic property activates the JAK2/STAT5A pathway via non-canonical manner, and promotes VM formation in GBM. The molecular communications between GSCs and DGCs offers a therapeutic strategy for targeting the neovascularization of GBM.

Assuntos

Neoplasias Encefálicas , Exossomos , Glioblastoma , Células-Tronco Neoplásicas , Neovascularização Patológica , RNA Circular , Fator de Transcrição STAT5 , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioblastoma/genética , RNA Circular/metabolismo , RNA Circular/genética , Humanos , Fator de Transcrição STAT5/metabolismo , Exossomos/metabolismo , Neovascularização Patológica/metabolismo , Linhagem Celular Tumoral , Animais , Células-Tronco Neoplásicas/metabolismo , Camundongos , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Fosforilação , Camundongos Nus , Regulação Neoplásica da Expressão Gênica , Camundongos Endogâmicos BALB C , Proteínas Supressoras de Tumor

RESUMO

Glioblastoma (GBM) is the most aggressive glial tumor of the adult brain, associated with invariably fatal outcome, and a deeper understanding of the underlying malignant mechanisms is necessary to address the current therapeutic failure. We previously demonstrated the role of the CXCL12/CXCR4 axis in GBM cell migration and resistance to ionizing radiation. The atypical chemokine receptor ACKR3, responsible for CXCL12 scavenging, was previously suggested as additional important player in the context of GBM. Following validation of the detection tools, we observed that ACKR3 is expressed within GBM patient tumor tissue, distributed in diverse cell types. In contrast to CXCR4, ACKR3 expression in patient-derived stem-like cells (GSCs) remains however low, while ACKR3 gene expression by tumor cells appears to be modulated by the in-vivo environment. Using overexpression models, we also showed that in vitro ACKR3 had no significant direct effect on cell proliferation or invasion. Altogether, these results suggest that in vitro ACKR3 plays a minor role in malignant GBM cell biology and that its expression is possibly regulated by in-vivo influences. The subtle and multifaceted functions ACKR3 could exert in GBM should therefore only be tackled within a comprehensive tumor microenvironment considering tumoral but also non-tumoral cells.

Assuntos

Neoplasias Encefálicas , Glioblastoma , Receptores CXCR , Glioblastoma/patologia , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Receptores CXCR/metabolismo , Receptores CXCR/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Regulação Neoplásica da Expressão Gênica , Proliferação de Células , Linhagem Celular Tumoral , Movimento Celular/genética , Quimiocina CXCL12/metabolismo , Quimiocina CXCL12/genética , Receptores CXCR4/metabolismo , Receptores CXCR4/genética , Microambiente Tumoral/genética

RESUMO

Glioblastoma (GBM) remains one of the most aggressive and lethal brain tumours, characterized by rapid progression and limited treatment options. This study investigated the regulatory roles of circular RNA circJUN, and its functional interaction with microRNA miR-3064 in GBM pathogenesis. We employed bioinformatic analyses and clinical sample validation to identify circJUN as a potential target in GBM. Subsequently, we engineered GBM cell lines with stable circJUN knockout or overexpression, and transfected them with miR-3064 mimic/inhibitor or IGFBP5 small interfering RNA (siRNA)/expression vector to elucidate the molecular mechanisms governing GBM proliferation and invasion. To investigate the in vivo effects, xenograft tumour models were established in nude mice using engineered cells to assess the roles of circJUN in tumour growth regulation. Our analyses revealed significant overexpression of circJUN in GBM tissues compared to healthy controls, which strongly correlated with poor patient prognosis. In vitro and in vivo experiments demonstrated that circJUN overexpression could enhance GBM cell proliferation and invasion. Mechanistic investigations uncovered EIF4A3 as an interacting factor of circJUN which promotes circJUN expression, and circJUN modulates miR-3064 activity to regulate the malignancy of GBM cells. Furthermore, we identified IGFBP5, a crucial regulator of cell growth, as a direct target of miR-3064, thereby establishing an additional layer of control over GBM proliferation and invasion. Our study unveils a complex regulatory network involving circJUN, miR-3064 and IGFBP5 in GBM pathogenesis, underscoring their potential as novel therapeutic targets for improving patient outcomes. Our findings not only contribute to the understanding of GBM biology but also pave the way for innovative therapeutic approaches in the management of this malignancy.

Assuntos

Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Glioblastoma , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina , Camundongos Nus , MicroRNAs , Invasividade Neoplásica , RNA Circular , MicroRNAs/genética , MicroRNAs/metabolismo , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/metabolismo , Humanos , Proliferação de Células/genética , RNA Circular/genética , RNA Circular/metabolismo , Animais , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Linhagem Celular Tumoral , Camundongos , Movimento Celular/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Masculino , Feminino , Ensaios Antitumorais Modelo de Xenoenxerto , Prognóstico

RESUMO

Despite considerable improvements in understanding the biology of glioblastoma (GB), it still remains the most lethal type of brain tumor in adults. The role of innate immune cells in the development of GB was recently described. In particular, the tumor-immune cell interactions are thought to be critical in enabling tumor tolerance and even protection against therapeutics. Interestingly, the GB cells express proteins belonging to the family of intracellular pattern-recognition receptors, namely the NOD-like receptors (NLRs). Their activation may trigger the formation of the inflammasome complex leading to the secretion of mature IL-1ß and IL-18 and thus resulting in cell death. Intrudingly, the expression of most NLRs was found to be correlated with tumor progression and poor prognosis. We speculate that recognizing the role of NOD-like receptors in GB has the potential to improve the effectiveness of diagnostic tools and prognosis, while also encouraging the development of novel precision medicine-based therapies.

Assuntos

Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/metabolismo , Glioblastoma/imunologia , Glioblastoma/patologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/genética , Prognóstico , Animais , Proteínas NLR/metabolismo , Inflamassomos/metabolismo , Inflamassomos/imunologia

RESUMO

Tumor-associatedmacrophages (TAMs) exhibit remarkable heterogeneity in glioblastoma. Spatially resolved single-cell transcriptomic studies identified a monocyte-derived TAM subset localized in the peri-necrotic niche, driven by hypoxic cues to acquire ahypoxia response signature. These hypoxia-TAMs destabilize endothelial adherens junctions through adrenomedullin paracrine signaling, promoting the formation of hyperpermeable neovasculature that impedes drug delivery. Blocking adrenomedullin produced by hypoxia-TAMs restores vascular integrity, increases drug deliveryinto tumors, and provides combinatorial therapeutic benefits. Here we discuss the heterogeneity of TAMs regarding functional states and locations in glioblastomas, and propose future directions for studying the temporospatial dynamics of multifaceted TAM. HIGHLIGHTS: Single-cell omics reveal a functionally and spatially distinct hypoxia-TAM subset in glioblastoma. Adrenomedullin secreted by hypoxia-TAM destabilizes tumor vasculature and its blockade enhances vessel integrity and drug delivery.

Assuntos

Glioblastoma , Macrófagos , Microambiente Tumoral , Glioblastoma/patologia , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Humanos , Macrófagos/metabolismo , Macrófagos Associados a Tumor/metabolismo