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Renoult, O.

Publications and source records attributed to Renoult, O..

3 recordsLinked to original sources

UCL-MetIsoLib: A Public High-Resolution Tandem Mass Spectrometry Library for HILIC-Based Isomer-Resolved Profiling of Glycolysis, Central Carbon Metabolism, and Beyond in Urine, Plasma, Tissues, Cells, and Patient-Derived Organoids

We present UCL-MetIsoLib, a publicly accessible high-resolution tandem mass spectrometry (HRMS/MS) library developed for HILIC-based, ion-pairing free, isomer-resolved metabolomics using a bioinert UHPLC system and the Acquity Premier BEH Amide column. The platform integrates two complementary methods operating under distinct chromatographic conditions (pH 3.5, ESI+; pH 11.0, ESI-), enabling broad metabolic coverage. A total of 334 metabolites are annotated in the library structure, with thiol derivatization incorporated into the extraction protocol to mitigate redox-driven artifacts. Metabolite identification is supported by 245 authentic reference standards and curated according to MSI Level 1 and Level 2 criteria. Validation followed FDA guidelines for bioanalytical method validation and was performed across five biological matrices--urine, plasma, tissues, cultured cells, and patient-derived colorectal organoids--with a U-13C, U-15N-labeled Amino Acid Mixture used as an isotope labeled internal standard. The method demonstrated high precision (<15% RSD intra-/inter-day) and recovery (85-115% across all QC levels). To demonstrate biological applicability, UCL-MetIsoLib was applied to a case study comparing healthy and colorectal cancer-derived organoids. The method enabled confident annotation of metabolite isomers, including key glycolytic intermediates such as DHAP and GA3P, as well as sugar phosphates from the glycolysis and pentose phosphate pathways. Metabolic alterations were observed in tumor organoids, including accumulation of nucleotide derivatives and shifts in central carbon metabolism. These findings emphasize the value of isomer-resolved spectral libraries in detecting biologically meaningful differences that are often missed in conventional untargeted metabolomics workflows.

systems biology↗

Pyruvate carboxylation identifies Glioblastoma Stem-like Cells opening new metabolic strategy to prevent tumor recurrence

Glioblastoma (GBM) are currently associated with a dismal prognosis due to therapeutic resistance. Within the diverse tumor subpopulations, Glioblastoma Stem-like Cells (GSC) have been involved in GBM recurrence. In our study, we demonstrated that these tumor cells can be identified through singular mitochondrial alternative metabolisms. Combining state-of-the-art metabolic studies and the development of a straightforward tumoroid model recapitulating key features of primary GBM cultures, we uncovered a significant use of -ketoglutarate reductive carboxylation and pyruvate carboxylation in tumoroid GBM cells, catalyzed respectively by isocitrate dehydrogenase and pyruvate carboxylase enzymes. We demonstrated that these singular metabolic features are shared by GBM cells from the mesenchymal subtype and radiation-escaping cells, also involved in recurrence. Finally, we demonstrated that pyruvate carboxylation is required for GBM cell survival in hypoxic niches where glutamine is restricted. Thus, besides providing a new way to identify GSC, our study also opens new therapeutic strategy to limit GBM recurrence.

cancer biology↗

Mechanistic insights of radiation-induced endothelial senescence impelling glioblastoma genomic instability at relapse

Despite aggressive clinical protocol, all glioblastoma (GBM) recur at the initial site within the irradiated peritumoral microenvironment. Whereas irradiated microenvironment has been recently proposed to accelerate GBM relapse, molecular and cellular mechanisms remain unknown. Here, using relevant in vitro and in vivo models, we decipher how radiation-induced endothelial senescence drives the emergence of aggressive GBM cells. Secretome (SASP) of radiation-induced senescent (RIS) endothelium enhances genomic instability and intratumoral heterogeneity in irradiated GBM cells. In-depth molecular studies revealed that CXCL5 and CXCL8, from the SASP, activate CXCR2 receptor on tumor cells leading to increased DNA hyper-replication, micronuclei formation and aneuploidy. Importantly, through CXCL5/8-CXCR2 axis activation, this SASP increases GBM aggressiveness in vivo. Both chemokines were detected in relapsing, but not primary, GBM biopsies and positively correlated with worst patient outcome. In conclusion, we identify new molecular and preclinical insights of relapsing GBM aggressiveness where RIS vascular niches fuel aggressive tumor emergence.

cancer biology↗