27438d85-70ea-4bb3-b088-6d826fa1a415 - samples
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PROVIDER: EGAD00001010156 | EGA |
REPOSITORIES: EGA
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Project description:We stratified 69 primary IDH-wt GBM patients into TMZ-resistant (n = 29) and sensitive (n = 40) groups, using TMZ screening of the corresponding patient-derived glioma stem-like cells (GSCs). Genomic and transcriptomic features were then examined to identify TMZ-associated molecular alterations. Subsequently, we developed a machine learning (ML) model to predict TMZ response from combined signatures. Moreover, TMZ response in multisector samples (52 tumor sectors from 18 cases) was evaluated to validate findings and investigate the impact of intra-tumoral heterogeneity on TMZ efficacy.
| EGAS00001006989 | EGA
Project description:Temozolomide (TMZ) is an important first-line treatment for glioblastoma (GBM), but there are limitations to TMZ response in terms of durability and dependence on the promoter methylation status of the DNA repair gene O6-methylguanine DNA methyltransferase (MGMT). MGMT-promoter-hypermethylated (MGMT-M) GBMs are more sensitive to TMZ than MGMT-promoter-hypomethylated (MGMT-UM) GBMs. Moreover, TMZ resistance is inevitable even in TMZ-sensitive MGMT-M GBMs. Hence, epigenetic reprogramming strategies are desperately needed in order to enhance TMZ response in both MGMT-M and MGMT-UM GBMs. In this study, we present novel evidence that the epigenetic reactivation of Tumor Suppressor Candidate 3 (TUSC3) can reprogram sensitivity of GBM stem cells (GSCs) to TMZ irrespective of MGMT promoter methylation status. Interrogation of TCGA patient GBM datasets confirmed TUSC3 promoter regulation of TUSC3 expression and also revealed a strong positive correlation between TUSC3 expression and GBM patient survival. Using a combination of loss-of-function, gain-of-function and rescue studies, we demonstrate that TUSC3 reactivation is associated with enhanced TMZ response in both MGMT-M and MGMT-UM GSCs. Further, we provide novel evidence that the demethylating agent 5-Azacitidine (5-Aza) reactivates TUSC3 expression in MGMT-M GSCs, whereas the combination of 5-Aza and MGMT inhibitor Lomeguatrib is necessary for TUSC3 reactivation in MGMT-UM GSCs. Lastly, we propose a pharmacological epigenetic reactivation strategy involving TUSC3 that leads to significantly prolonged survival in MGMT-M and MGMT-UM orthotopic GSCs models. Collectively, our findings provide a framework and rationale to further explore TUSC3-mediated epigenetic reprogramming strategies that could enhance TMZ sensitivity and outcomes in GBM. Mechanistic and translational evidence gained from such studies could contribute towards optimal design of impactful trials for MGMT-UM GBMs that currently do not have good treatment options.
2024-11-26 | GSE282886 | GEO
Project description:Background. Glioblastoma multiforme (GBM) exhibits a cellular hierarchy with a subpopulation of stem-like cells known as glioblastoma stem cells (GSCs), that drive tumor growth and contribute to treatment resistance. NAD(H) emerged as a crucial factor influencing GSCs. Methods. A multistep process of machine learning algorithms was implemented to construct the glioma stemness-related score (GScore). Further in silico and patient tissue analyses validated the predictive ability of the GScore and identified a potential target, CYP3A5. Loss-of-function or gain-of-function genetic experiments were performed to assess the impact of CYP3A5 on the self-renewal and chemoresistance of GSCs both in vitro and in vivo. Mechanistic studies were conducted using nontargeted metabolomics, RNA-seq, seahorse, transmission electron microscopy, immunofluorescence, flow cytometry, ChIP‒qPCR, RT‒qPCR, western blotting, etc. The efficacy of pharmacological inhibitors of CYP3A5 was assessed in vivo. Results. Based on the proposed GScore, we identify a GSC target CYP3A5, which is highly expressed in GSCs and temozolomide (TMZ)-resistant GBM patients. This elevated expression of CYP3A5 is attributed to transcription factor STAT3 activated by EGFR signaling or TMZ treatment. Depletion of CYP3A5 impairs self-renewal and TMZ resistance in GSCs. Mechanistically, CYP3A5 maintains mitochondrial fitness to promote GSC metabolic adaption through the NAD⁺/NADH-SIRT1-PGC1α axis. Additionally, CYP3A5 enhances the activity of NAD-dependent enzyme PARP to augment DNA damage repair. Treatment with CYP3A5 inhibitor alone or together with TMZ effectively suppresses tumor growth in vivo. Conclusion. Together, this study suggests that GSCs activate STAT3 to upregulate CYP3A5 to fine-tune NAD⁺/NADH for the enhancement of mitochondrial functions and DNA damage repair, thereby fueling tumor proliferation and conferring TMZ resistance, respectively. Thus, CYP3A5 represents a promising target for GBM treatment.
2025-01-08 | GSE277539 | GEO
Project description:The poor prognosis of patients with glioblastoma is partly due to resistance to standard treatment, which combines chemoradiation using temozolomide (TMZ). The concept of cancer stem cells provided new insight into tumor resistance and management, and isolated Glioblastoma stem-like cells (GSCs) which contribute to this therapy resistance. Bone morphogenetic protein 4 (BMP4) is a differentiation factor that stimulates astroglial differentiation of such GSCs, thereby reducing their self-renewal. Exposing GSCs to BMP4 could therefore sensitize them to chemotherapy with TMZ, but previous studies with various treatment paradigms have produced contradictory results in this matter. Therefore, we re-defined the optimal treatment paradigm for the combination of TMZ and BMP4 and subsequently re-assessed the inter-tumoral variability in response to co-treatment with TMZ+BMP4 in vitro. First, the simultaneous treatment was found more effective than sequential therapy. Second, after application of our optimized treatment protocol, 70% of a total of 20 patient-derived glioblastoma cultures showed synergy when the treatments were combined. The synergistic effect was a result of increased cellular apoptosis and not of decreased proliferation. Comparative RNA-sequencing suggested that combination treatment results in decreased MAPK signaling. We conclude that addition of BMP4 to standard therapy with TMZ could enlarge the group of patients with good therapeutic response.
| EGAS00001007095 | EGA
Project description:Accumulating evidence suggests that glioma stem cells (GSCs), rare cells characterised by pluripotency and self-renewal, are responsible for glioblastoma (GBM) propagation, recurrence and resistance to therapy. Differentiation with bone morphogenic proteins (BMPs) is considered to be a promising approach to eliminate GSCs and sensitise glioma to chemotherapeutics. Epidermal growth factor receptor (EGFR) gene alterations are detected in more than a half of GBMs, however, the role of EGFR in chemoresistance of glioma stem cells remain elusive. Here, we investigated whether EGFR signalling affects BMP4-induced differentiation of GSCs and their response to an alkylating drug temozolomide (TMZ). We show that BMP4 triggers Smad signalling cascade in glioma stem cells independently of the EGFR level. BMP4 down-regulated levels of pluripotency markers (SOX2 and OLIG2) with the concomitant induction of astrocytic (GFAP) and neuronal (b-Tubulin III) markers. However, significant differences in chemotherapy outcomes were observed in glioma stem cells with different EGFR levels. BMP4-induced differentiation did not enhance sensitivity to TMZ in EGFRlow GSCs, in contrast to EGFRhigh GSCs, which were undergoing apoptosis. We identified differences in cell cycle regulation by analyses of cell cycle phase distribution and cell-cycle-related proteins. In cells with lower EGFR expression BMP4 triggered the G1 cell cycle arrest, not detected in EGFRhigh cells. RNA-seq profiles further highlighted transcriptomic alternations and distinct processes characterizing EGFR-dependent responses in course of BMP4-induced differentiation. We identified AKT/FOXO3a axis controlling of BIM (the pro-apoptotic BCL-2 family protein) as operating only in EGFRhigh BMP4-differentiated and TMZ-treated cells.
2021-05-05 | GSE140441 | GEO
Project description:Purpose: Proficient DNA repair by homologous recombination (HR) facilitates resistance to chemo-radiation in glioma stem cells (GSCs). We evaluated whether compromising HR by targeting HSP90, a molecular chaperone required for the function of key HR proteins, using onalespib, a long-acting, brain-penetrant HSP90 inhibitor, would sensitize high-grade gliomas to chemo-radiation in vitro and in vivoExperimental Design: The ability of onalespib to deplete HR client proteins, impair HR repair capacity, and sensitize GBM to chemo-radiation was evaluated in vitro in GSCs, and in vivo using zebrafish and mouse intracranial glioma xenograft models. The effects of HSP90 inhibition on the transcriptome and cytoplasmic proteins was assessed in GSCs and in ex vivo organotypic human glioma slice cultures.Results: Treatment with onalespib depleted CHK1 and RAD51, two key proteins of the HR pathway, and attenuated HR repair, sensitizing GSCs to the combination of radiation and temozolomide (TMZ). HSP90 inhibition reprogrammed the transcriptome of GSCs and broadly altered expression of cytoplasmic proteins including known and novel client proteins relevant to GSCs. The combination of onalespib with radiation and TMZ extended survival in a zebra fish and a mouse xenograft model of GBM compared to the standard of care (radiation and TMZ) or onalespib with radiation.Conclusions: The results of this study demonstrate that targeting HR by HSP90 inhibition sensitizes GSCs to radiation and chemotherapy and extends survival in zebrafish and mouse intracranial models of GBM. These results provide a preclinical rationale for assessment of HSP90 inhibitors in combination with chemoradiation in GBM patients.
2022-04-15 | GSE193635 | GEO
Project description:Introduction: The EORTC22033-26033 clinical trial investigated whether initial temozolomide (TMZ) chemotherapy confers survival advantage compared to radiotherapy (RT) in low grade glioma patients. In this study we performed gene expression profiling on tissues from this trial in order to identify markers associated with progression free survival and treatment response in this well-defined cohort of patients. Methods: Gene expression profiling, performed on 195 samples, was used to assign tumors to one of six intrinsic glioma subtypes (IGS; molecularly similar tumors predefined by unsupervised gene expression analysis) and to extract the cellular composition of immune infiltrates. DNA copy number changes were determined on samples assigned to IGS-16. Results: We confirm that IGS-subtypes are prognostic in EORTC22033-26033 clinical trial samples. Specific genetic changes segregate in distinct IGS subtypes: most samples assigned to IGS-9 have IDH-mutations combined with 1p19q codeletion, samples assigned to IGS-17 have IDH-mutations with intact 1p19q chromosomal arms and samples assigned to other intrinsic subtypes often are IDH-wildtype and 1p19q intact. A trend towards benefit from RT compared to TMZ was observed for samples assigned to IGS-9 (HR for TMZ is 1.90, 95% CI [0.95, 3.80], P=0.065), but not for samples assigned to IGS-17 (HR for TMZ vs RT is 0.87, 95% CI[0.50, 1.51], P=0.62). We did not identify genes significantly associated with progression free survival (PFS) within intrinsic subtypes, though follow-up time is limited. We also show that LGGs and GBMs differ in their immune-infiltrate with LGGs having higher suppressor and lower effector cell populations compared to GBMs. This suggests that LGGs are less amenable to checkpoint inhibitor type immune therapies than GBMs. Gene expression analysis and copy number analysis also identified one patient with a pilocytic astrocytoma (PA). Conclusion: Intrinsic glioma subtypes are prognostic for PFS in EORTC22033-26033 clinical trial samples.
2019-03-19 | GSE107850 | GEO
Project description:Immune landscape of Isocitrate Dehydrogenase (IDH) stratified human gliomas
| PRJNA922456 | ENA
Project description:Chaperone-mediated autophagy (CMA) is a homeostatic process essential for the lysosomal degradation of individual proteins. CMA activity directly depends on the levels of LAMP2A, critical receptor at the lysosomal membrane, to which CMA substrate proteins are bound. In glioblastoma (GBM), the most common and aggressive brain cancer in the adulthood, high levels of LAMP2A have been linked to TMZ resistance and tumor-associated pericytes. However, the implication of LAMP2A, and hence CMA, in glioblastoma stem cells (GSCs) remains unknown. In this work, we show that LAMP2A expression is enriched in patient-derived GSC population and its knock-down diminishes GSCs tumorigenic activities. Proteomic and transcriptomic analysis of LAMP2A knocked-down GSCs revealed reduced extracellular matrix (ECM) interaction effectors in both analyses. Moreover, immune system and mitochondrial metabolism related pathways were remarkably deregulated at proteome level, whereas PI3K-AKT and p53 pathways were altered in RNAseq study. Moreover, clinical samples of GBM tissue presented overexpression of LAMP2 and its high levels correlated with advanced glioma grade and poor overall survival. In conclusion, we identified a novel role of CMA directly regulating GSCs activity via multiple pathways at proteome and transcriptome level.
2023-03-11 | PXD027069 | Pride
Project description:Chaperone-mediated autophagy (CMA) is a homeostatic process essential for the lysosomal degradation of individual proteins. CMA activity directly depends on the levels of LAMP2A, critical receptor at the lysosomal membrane, to which CMA substrate proteins are bound. In glioblastoma (GBM), the most common and aggressive brain cancer in the adulthood, high levels of LAMP2A have been linked to TMZ resistance and tumor-associated pericytes. However, the implication of LAMP2A, and hence CMA, in glioblastoma stem cells (GSCs) remains unknown. In this work, we show that LAMP2A expression is enriched in patient-derived GSC population and its knock-down diminishes GSCs tumorigenic activities. Proteomic and transcriptomic analysis of LAMP2A knocked-down GSCs revealed reduced extracellular matrix (ECM) interaction effectors in both analyses. Moreover, immune system and mitochondrial metabolism related pathways were remarkably deregulated at proteome level, whereas PI3K-AKT and p53 pathways were altered in RNAseq study. Moreover, clinical samples of GBM tissue presented overexpression of LAMP2 and its high levels correlated with advanced glioma grade and poor overall survival. In conclusion, we identified a novel role of CMA directly regulating GSCs activity via multiple pathways at proteome and transcriptome level.
2022-08-02 | PXD029393 | Pride