Gene expression profile of Radiatiom resistant BRAFV400E type pediatric low-grade gliomas
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE268207 | GEO | 2026/05/22
REPOSITORIES: GEO
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Project description:Inhibitors of the MAPK pathway (MAPKi) have shown significant activity in treatment of childhood BRAF-activated brain tumors. However, for tumors harboring BRAFV600E mutations, the drugs are rarely curative, and patients can become refractory to treatment. Combining MAPKi with low dose X-ray therapy (XRT) has the potential to improve the cure rate, but development of XRT resistance poses a major challenge. To understand the mechanisms of radiation resistance in BRAFV600E type pediatric low-grade gliomas, radiation resistance models were developed by using IC365 \ pediatric low-grade glioma (PLGG) PDX model harboring BRAFV600E mutation. RNA sequencing was performed to determine the gene expression profile of primary tumors and resistant tumors. Each tumor tissue was transplanted to 3 scid mice respectively. When tumor volume reach ~0.3~0.6 cm3, tumor tissue (from three mice, triplicates) were collected and were snap-frozen in liquid nitrogen. RNA was isolated and applied to subsequent 100bp paired read sequencing run with Illumina NovaSeq 6000 platform at 100 bp paired-end module.
2025-09-17 | GSE284577 | GEO
Project description:Inhibitors of the MAPK pathway (MAPKi) have shown significant activity in treatment of childhood BRAF-activated brain tumors. However, for tumors harboring BRAFV600E mutations, the drugs are rarely curative, and patients can become refractory to treatment. Combining MAPKi with low dose X-ray therapy (XRT) has the potential to improve the cure rate, but development of XRT resistance poses a major challenge. To understand the mechanisms of radiation resistance in BRAFV600E type pediatric low-grade gliomas, radiation resistance models were developed by using BT-40 pediatric low-grade glioma (PLGG) PDX model harboring BRAFV600E mutation. RNA sequencing was performed to determine the gene expression profile of primary tumors and resistant tumors. Each tumor tissue was transplanted to 3 scid mice respectively. When tumor volume reach ~0.3~0.6 cm3, tumor tissue (from three mice, triplicates) were collected and were snap-frozen in liquid nitrogen. RNA was isolated and applied to subsequent 100bp paired read sequencing run with Illumina NovaSeq 6000 platform at 100 bp paired-end module.
2025-09-17 | GSE271064 | GEO
Project description:Pediatric low-grade gliomas (pLGG) have shown heterogeneous responses to MAPK inhibitors (MAPKi) in clinical trials. A predictive feature for stratification is needed to identify patients likely to benefit from MAPKi therapy. MAPK-related genes differentially regulated between MAPKi sensitive and non-sensitive cell lines from the Genomics of Drug Sensitivity in Cancer dataset identified class-specific MAPKi sensitivity gene signatures used to calculate the MAPKi sensitivity score (MSS) via single sample gene set enrichment analysis. The MSS discerned gliomas with varying MAPK alterations from those without, and was higher in pLGG compared to other pediatric CNS tumors. As in clinical trials, the MSS was heterogeneous within pLGGs with a common MAPK alteration. A positive correlation between the MSS and the predicted immune infiltration determined by the ESTIMATE signature was observed. The MSS therefore represents a potential tool for the stratification of pLGG patients, worth of further investigation in upcoming clinical trials. Our data could support a role of microglia in the response to MAPKi, warranting further validation.
2023-06-27 | GSE222850 | GEO
Project description:Pediatric ependymoma has relatively low frequencies of DNA mutations, which suggest that epigenetics may drive tumors. However, the epigenetic mechanisms for recurrent ependymoma are still poorly understood. Here, we performed longitudinal and comprehensive DNA methylation and gene expression analysis for recurrent pediatric ependymoma tumors from 10 patients, total 46 DNA methylomes (including primary tumors and matched recurrent tumors; normal pediatric brain tissues and PDOX tumors). Both RELA and PFA tumors maintained the subtype DNA methylation signatures during repeated relapses. We further identified the potential DNA methylation predictors, drivers and boosters and their potential regulated genes for recurrent ependymoma tumors. Increased DNA methylation levels within H3K4me1 enriched regions indicates disturbed functions of LSD1 gene in recurrent ependymoma tumors. Combining novel LSD1 inhibitor SYC-836 with radiation (XRT) significantly prolonged animal survival times in PDOX models of recurrent PFA ependymoma. Our PDOX models provide a unique platform for preclinical testing drugs and development of new therapy for pediatric recurrent ependymoma.
2022-07-12 | GSE156619 | GEO
Project description:Background. The impact of adjuvant radiation therapy (XRT) after gross-total resection (GTR) of atypical meningiomas (AMs) has always been controversial. Considering that intrinsic differences among these AMs may exist, our study aim to seek which kind of these patients is more likely to recur and to explore its underlying causes. Methods. The case database and the pathological records of our hospital between Jan 2008 and Jul 2016 were reviewed, 46 AMs received early XRT after GTR (confirmed by the 2016 revision of WHO diagnostic criteria). Microarray analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to detect aberrant expression of microRNAs (miRs). Immunohistochemical staining for the biomarker was performed, and its expression was semi-quantitative analyzed by using Image Pro Plus (IPP) 6.0. Univariate and multivariate Cox proportional hazards regression analysis were used to assess the correlation between various factors and recurrence. Results. Microarray analysis and qRT-PCR demonstrated that miR-221/222 were upregulated in radiotherapy resistance (RTR) AM tissues compared with radiotherapy sensitive (RTS) AM tissues. Multivariable analysis showed that malignant progression (MP) (P=0.011), low expression level of PTEN (P=0.026) and skull-base AMs (P=0.028) were associated with higher recurrence. Conclusion. We first demonstrated that upregulated miR-221/222 could decrease the radiosensitivity of the combination-therapy-treated AMs. Meanwhile, AMs with low expression level of PTEN, skull-base located were more likely to recur. MP-AMs were associated with increased possibility of recurrence by comparing to primary AMs. Treatment and consideration of MP-meningiomas were advocated to refer to the therapeutic strategy for higher grade meningiomas rather than restricted to its present grade.
2021-06-06 | GSE115444 | GEO
Project description:Background<br>Primitive brain tumors are the first cause of cancer-related death in children. Tumor cells with stem-like properties (TSCs), thought to account for tumorigenesis and therapeutic resistance, have been isolated from high-grade gliomas in adults. Whether TSCs are a common component of pediatric brain tumors and are of clinical relevance remains to be determined. <br>Methodology/Principal findings<br>Tumor cells with self-renewal properties were isolated with cell biology techniques from a majority of 55 pediatric brain tumors samples, regardless of their histopathologies and grades of malignancy (57% of embryonal tumors, 57% of low-grade gliomas and neuro-glial tumors, 70% of ependymomas, 91% of high-grade gliomas). The vast majority (10/12) of high-grade glioma-derived oncospheres sustained long-term self-renewal numbers akin to neural stem cells (>7 self-renewals), whereas cells with limited renewing abilities akin to neural progenitors dominated in all other tumor types. Regardless of tumor entities, the young age group was associated with self-renewal properties akin to neural stem cells (P=0.05, chi-square test). TSCs shared a complex molecular profile combining embryonic stem cell markers with elements controlling neural stem cell properties and epithelio-mesenchymal transitions. They were radio- and chemoresistant and formed aggressive tumors after intracerebral grafting. Survival analysis of the cohort showed an association between isolation of TSCs with long-term self-renewal abilities and a patients higher mortality rate (P = 0.022, log-rank test). Patients bearing cells with limited self-renewal properties constituted an intermediate group of survival but which did not reach statistical significance. <br>Conclusions/Significance<br>In brain tumors affecting adult patients, TSC have been isolated only from high-grade gliomas. In contrast, our data show that tumor cells with stem cell-like or progenitor-like properties can be isolated from a wide range of histological sub-types and grades of pediatric brain tumors. They suggest that cellular mechanisms fueling tumor development differ between adult and pediatric brain tumors.<br>
2011-09-07 | E-MEXP-2909 | biostudies-arrayexpress
Project description:Background<br>Primitive brain tumors are the first cause of cancer-related death in children. Tumor cells with stem-like properties (TSCs), thought to account for tumorigenesis and therapeutic resistance, have been isolated from high-grade gliomas in adults. Whether TSCs are a common component of pediatric brain tumors and are of clinical relevance remains to be determined. <br>Methodology/Principal findings<br>Tumor cells with self-renewal properties were isolated with cell biology techniques from a majority of 55 pediatric brain tumors samples, regardless of their histopathologies and grades of malignancy (57% of embryonal tumors, 57% of low-grade gliomas and neuro-glial tumors, 70% of ependymomas, 91% of high-grade gliomas). The vast majority (10/12) of high-grade glioma-derived oncospheres sustained long-term self-renewal numbers akin to neural stem cells (>7 self-renewals), whereas cells with limited renewing abilities akin to neural progenitors dominated in all other tumor types. Regardless of tumor entities, the young age group was associated with self-renewal properties akin to neural stem cells (P=0.05, chi-square test). TSCs shared a complex molecular profile combining embryonic stem cell markers with elements controlling neural stem cell properties and epithelio-mesenchymal transitions. They were radio- and chemoresistant and formed aggressive tumors after intracerebral grafting. Survival analysis of the cohort showed an association between isolation of TSCs with long-term self-renewal abilities and a patientM-^Rs higher mortality rate (P = 0.022, log-rank test). Patients bearing cells with limited self-renewal properties constituted an intermediate group of survival but which did not reach statistical significance. <br>Conclusions/Significance<br>In brain tumors affecting adult patients, TSC have been isolated only from high-grade gliomas. In contrast, our data show that tumor cells with stem cell-like or progenitor-like properties can be isolated from a wide range of histological sub-types and grades of pediatric brain tumors. They suggest that cellular mechanisms fueling tumor development differ between adult and pediatric brain tumors.<br>
2011-09-07 | E-MEXP-2910 | biostudies-arrayexpress
Project description:With the increasing use of immunotherapy in cancer, understanding the tumor immune microenvironment (TIME) has become increasingly important. There has been great success in treatment of some pediatric high-grade gliomas with immune checkpoint inhibition, however overall, the immune microenvironment in pediatric brain tumors remains poorly understood. Accordingly, we developed a clinical immune-oncology gene expression assay and used it to profile a diverse range of pediatric brain tumors with detailed clinical and molecular annotation, including a total of 1379 cases. Our findings demonstrate the critical importance of understanding the TIME to guide the prognosis and management of pediatric brain tumors. In pediatric low-grade gliomas we identified distinct patterns of immune activation with prognostic significance in BRAF V600E mutant tumors. In pediatric high-grade gliomas, we observed elevated inflammation and T cell infiltrates in tumors that have historically been considered immune cold, as well as genomic correlates of inflammation levels. In our cohort of mismatch repair deficient high-grade gliomas treated with immune checkpoint inhibition, we found that high tumor inflammation signature was a significant predictor of treatment response. Furthermore, we demonstrated the potential for multimodal biomarkers to improve the treatment stratification of these patients. Importantly, while overall patterns of immune activation were observed for histologically and genomically defined tumor types, there was nonetheless significant variability within each diagnostic entity, indicating that the immune response must be evaluated as an independent feature. In sum, in addition to the histology and molecular profile, this work establishes the importance of assessing and reporting on the tumor immune microenvironment as an essential axis of cancer diagnosis in the era of personalized medicine.
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Project description:Langerhans cell histiocytosis (LCH) is a clonal hematopoietic disorder defined by tumorous lesions containing CD1a+/CD207+ cells. Two severe complications of LCH are systemic hyperinflammation and progressive neurodegeneration. The scarcity of primary samples and lack of appropriate models limit our mechanistic understanding of LCH pathogenesis and affect patient care. We generated a human in vitro model for LCH using induced pluripotent stem cells (iPSCs) harboring the BRAFV600E mutation, the most common genetic driver of LCH. We show that BRAFV600E/WT iPSCs display myelo-monocytic skewing during hematopoiesis and spontaneously differentiate into CD1a+/CD207+ cells that are similar to lesional LCH cells and are derived from a CD14+ progenitor. BRAFV600E modulates the expression of key transcription factors regulating monocytic differentiation and leads to an upregulation of pro-inflammatory molecules and LCH marker genes early during myeloid differentiation. BRAFV600E-induced transcriptomic changes are reverted upon treatment with MAPK-pathway inhibitors (MAPKi). Importantly, MAPKi does not affect myeloid progenitors but reduces only the mature CD14+ cell population. Furthermore, iPSC-derived neurons (iNeurons) cocultured with BRAFV600E/WT microglia-like cells (iMGL), differentiated from iPSC-derived CD34+ progenitors, exhibit signs of neurodegeneration with neuronal damage and release of neurofilament light chain. In summary, our model provides a platform to study the effect of BRAFV600E in different hematopoietic cell types and provides a tool to compare and identify novel approaches for the treatment of BRAFV600E-driven diseases.
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Project description:As the progression of low-grade diffuse astrocytomas into grade 4 tumors significantly impacts patient prognosis, a better understanding of this process is of paramount importance for improved patient care. In this project, we analyzed matched IDH-mutant astrocytomas before and after progression to grade 4 from six patients (discovery cohort) with genome-wide sequencing and 21 additional patients with targeted sequencing. The Cancer Genome Atlas (TCGA) data from 595 diffuse gliomas provided supportive information. All patients in our discovery cohort received radiation, all but one underwent chemotherapy, and no patient received temozolomide before progression to grade 4 disease. One case in the discovery cohort exhibited a hypermutation signature associated with the inactivation of the MSH2 and DNMT3A genes. In other patients, the number of chromosomal rearrangements and deletions increased in grade 4 tumors. Tumor progression was associated with upregulation of cell cycle progression, migration, and DNA damage repair-related genes. The cell cycle checkpoint genes CDKN2A or RB1 were most commonly inactivated, followed by activating growth factor receptor gene alterations in cases with homozygous CDKN2A deletion. We also detected progression-related alterations in DNA repair pathway genes associated with the promotion of error-prone DNA repair, thus facilitating tumor progression. The homologous recombination repair gene RAD51B was hemizygously deleted in all but one progressed tumor in our discovery cohort. In our retrospective analysis of patient treatment and survival timelines, the combination of postoperative radiation and chemotherapy (mainly temozolomide) outperformed radiation especially in the grade 3 tumor cohort, in which it was typically given after primary surgery. Our results support previous notions that treatment contributes to tumor evolution and suggest that altered DNA repair has a role in treatment resistance and tumor progression.
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