Publications by authors named "Bielle F"

Transition of cytosine to thymine in CpG dinucleotides is the most frequent type of mutation in cancer. This increased mutability is commonly attributed to the spontaneous deamination of 5-methylcytosine (5mC), which is normally repaired by the base-excision repair (BER) pathway. However, the contribution of 5mC deamination in the increasing diversity of cancer mutational signatures remains poorly explored.

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Cranial dural arteriovenous fistulas (DAVFs) that display cortical venous drainage are at risk of hemorrhage, unlike spinal DAVFs, which seldom bleed. The underlying mechanism for this difference is poorly understood. We hypothesized that cerebral veins are more fragile than spinal veins due to differences in histologic compositions.

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CIC fusions have been described in two different central nervous system (CNS) tumor entities. On one hand, fusions of CIC or ATXN1 genes belonging to the same complex of transcriptional repressors, were reported in the CIC-rearranged, sarcoma (SARC-CIC). The diagnosis of this tumor type, which was recently added to the World Health Organization (WHO) Classification of CNS tumors, is difficult mainly because the data concerning its histopathology (as compared to its soft tissue counterpart), immunoprofile, and clinical as well as radiological characteristics are scarce in the literature.

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The standard of care for adult patients with gliomas, glioneuronal and neuronal tumors consists of combinations of surgery, radiotherapy, and chemotherapy. For many systemic cancers, targeted treatments are a major part of the standard treatment, however, the predictive significance of most of the targets for treatment in systemic cancer are less well established in central nervous system (CNS) tumors . In 2023 the EANO Guideline Committee presented evidence based recommendations for rational testing of molecular targets for targeted treatments.

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Purpose: Patients with IDH-mutant 1p/19q-codeleted grade 3 oligodendroglioma (O3) benefit from adding alkylating agent chemotherapy to radiotherapy (RT). However, the optimal chemotherapy regimen between procarbazine, 1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), and vincristine (PCV) and temozolomide (TMZ) remains unclear given the lack of randomized trial data comparing both regimens.

Methods: The objective was to assess the overall survival (OS) and progression-free survival (PFS) associated with first-line PCV/RT versus TMZ/RT in patients newly diagnosed with O3.

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Article Synopsis
  • Microsatellite instability (MSI), often linked to mismatch repair deficiency in colorectal cancer (CRC), leads to numerous noncoding DNA mutations, particularly affecting RNA splicing sites.
  • This research shows that these noncoding mutations happen early in tumor development, even before the cancer cells become mutated in their coding regions, and are associated with altered splicing patterns in mRNA.
  • The altered RNA splicing impacts cellular differentiation and promotes the initiation of MSI CRC, indicating that these noncoding changes are significant for cancer progression before traditional coding mutations occur.
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Background: Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE/HS) is the most common cause of drug-resistant focal seizures and surgical resection is the primary treatment option, with seizure-free rates ranging from 60 to 80%. However, data on postsurgical seizure outcomes in patients ≥ 50 years of age are limited. This study aimed to assess the efficacy and safety of surgery in this age group compared to younger patients.

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Background And Purpose: Isocitrate dehydrogenase () mutation and 1p/19q codeletion classify adult-type diffuse gliomas into 3 tumor subtypes with distinct prognoses. We aimed to evaluate the performance of edited MR spectroscopy for glioma subtyping in a clinical setting, via the quantification of D-2-hydroxyglutarate (2HG) and cystathionine. The delay between this noninvasive classification and the integrated histomolecular analysis was also quantified.

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Non-Hodgkin lymphomas (NHL) commonly occur in immunodeficient patients, both those infected by human immunodeficiency virus (HIV) and those who have been transplanted, and are often driven by Epstein-Barr virus (EBV) with cerebral localization, raising the question of tumor immunogenicity, a critical issue for treatment responses. We investigated the immunogenomics of 68 lymphoproliferative disorders from 51 immunodeficient (34 post-transplant, 17 HIV+) and 17 immunocompetent patients. Overall, 72% were large B-cell lymphoma and 25% were primary central nervous system lymphoma, while 40% were EBV+.

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Background: Oncogenic FGFR-TACC fusions are present in 3-5% of high-grade gliomas (HGGs). Fexagratinib (AZD4547) is an oral FGFR1-3 inhibitor with preclinical activity in FGFR-TACC+ gliomas. We tested its safety and efficacy in patients with recurrent FGFR-TACC + HGGs.

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Background And Objectives: New-onset refractory status epilepticus (NORSE) occurs in previously healthy children or adults, often followed by refractory epilepsy and poor outcomes. The mechanisms that transform a normal brain into an epileptic one capable of seizing for prolonged periods despite treatment remain unclear. Nonetheless, several pieces of evidence suggest that immune dysregulation could contribute to hyperexcitability and modulate NORSE sequelae.

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A novel methylation class, "neuroepithelial tumor, with PLAGL1 fusion" (NET-PLAGL1), has recently been described, based on epigenetic features, as a supratentorial pediatric brain tumor with recurrent histopathological features suggesting an ependymal differentiation. Because of the recent identification of this neoplastic entity, few histopathological, radiological and clinical data are available. Herein, we present a detailed series of nine cases of PLAGL1-fused supratentorial tumors, reclassified from a series of supratentorial ependymomas, non-ZFTA/non-YAP1 fusion-positive and subependymomas of the young.

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Background: Novel effective treatments are needed for recurrent IDH mutant high-grade gliomas (IDHm HGGs). The aim of the multicentric, single-arm, phase II REVOLUMAB trial (NCT03925246) was to assess the efficacy and safety of the anti-PD1 Nivolumab in patients with recurrent IDHm HGGs.

Patients And Methods: Adult patients with IDHm WHO grade 3-4 gliomas recurring after radiotherapy and ≥ 1 line of alkylating chemotherapy were treated with intravenous Nivolumab until end of treatment (12 months), progression, unacceptable toxicity, or death.

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Background: Glioblastoma (GBM) is the most common devastating primary brain cancer in adults. In our clinical practice, median overall survival (mOS) of GBM patients seems increasing over time.

Methods: To address this observation, we have retrospectively analyzed the prognosis of 722 newly diagnosed GBM patients, aged below 70, in good clinical conditions (i.

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The evolutionary trajectory of glioblastoma (GBM) is a multifaceted biological process that extends beyond genetic alterations alone. Here, we perform an integrative proteogenomic analysis of 123 longitudinal glioblastoma pairs and identify a highly proliferative cellular state at diagnosis and replacement by activation of neuronal transition and synaptogenic pathways in recurrent tumors. Proteomic and phosphoproteomic analyses reveal that the molecular transition to neuronal state at recurrence is marked by post-translational activation of the wingless-related integration site (WNT)/ planar cell polarity (PCP) signaling pathway and BRAF protein kinase.

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We report here about two novel tumours classified as extraventricular neurocytomas (EVN) using DNA-methylation profiling, associated with NTRK2 fusions instead of the usual FGFR1 alterations so far attributed to this tumoural entity. We present the second detailed case of an intraventricular presentation in the MC EVN. Our findings broaden the spectrum of MC EVN and have implications in terms of diagnosis, therapy and terminology.

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Article Synopsis
  • Dihydroxy-6-[18F]fluoro-L-phenylalanine (18F-FDOPA) PET is used for managing high-grade gliomas (HGGs), but its effectiveness varies by glioma subtype and the role of LAT1 expression post-treatment is unclear.
  • A study analyzed 39 patients with recurrent HGGs and found that IDH-mutant astrocytomas had higher 18F-FDOPA uptake and LAT1 expression compared to IDH-wildtype glioblastomas.
  • The results indicate that higher LAT1 scores are linked to better progression-free survival in IDH-mutant HGGs, suggesting a potential connection between LAT1 expression and glioma
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Objective: Mesial Temporal Lobe Epilepsy-associated Hippocampal Sclerosis (MTLE-HS) is a syndrome associated with various aetiologies. We previously identified CD34-positive extravascular stellate cells (CD34+ cells) possibly related to BRAF oncogenic variant in a subset of MTLE-HS. We aimed to identify the BRAF oncogenic variants and characterise the CD34+ cells.

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Background Noninvasive identification of glioma subtypes is important for optimizing treatment strategies. Purpose To compare the in vivo neurochemical profiles between isocitrate dehydrogenase (IDH) 1-mutant 1p/19q codeleted gliomas and their noncodeleted counterparts measured by MR spectroscopy at 3.0 T with a point-resolved spectroscopy (PRESS) sequence optimized for D-2-hydroxyglutarate (2HG) detection.

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Aims: The distinction between CNS WHO grade 2 and grade 3 is instrumental in choosing between observational follow-up and adjuvant treatment for resected astrocytomas IDH-mutant. However, the criteria of CNS WHO grade 2 vs 3 have not been updated since the pre-IDH era.

Methods: Maximal mitotic activity in consecutive high-power fields corresponding to 3 mm was examined for 118 lower-grade astrocytomas IDH-mutant.

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Article Synopsis
  • A study involving 20 COVID-19 cases identified cerebral microangiopathy in six patients, marked by changes in white matter and small artery diseases as seen on MRI.
  • The condition featured perivascular alterations such as vacuolization, macrophage clusters, and large axonal swellings, suggesting blood-brain barrier disruption without evidence of direct viral presence in the brain.
  • Detection of the SARS-CoV-2 spike protein in brain endothelial cells, particularly within the Golgi apparatus, indicates a unique interaction that might affect vascular permeability and contribute to long-term neurological effects of COVID-19.
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