Biology subjects

Garnier, N.

Publications and source records attributed to Garnier, N..

3 recordsLinked to original sources

bioRxiv2023

Mutational and transcriptional landscape of pediatric B-cell precursor lymphoblastic lymphoma

Pediatric B-cell precursor (BCP) lymphoblastic malignancies are neoplasms with manifestation either in bone marrow/blood (BCP acute lymphoblastic leukemia, BCP-ALL) or less common in extramedullary tissue (BCP lymphoblastic lymphoma, BCP-LBL). Although both presentations are similar in morphology and immunophenotype molecular studies are virtually restricted to BCP-ALL so far. The lack of molecular studies on BCP-LBL is probably due to its rarity and the restriction to tiny, mostly formalin-fixed paraffin embedded (FFPE) tissues. Here we present the first comprehensive mutational and transcriptional analysis of what we consider the largest BCP-LBL cohort described to date (n=97). Whole exome sequencing indicates a mutational spectrum of BCP-LBL strikingly similar to that found in BCP-ALL. However, epigenetic modifiers were more frequently mutated in BCP-LBL, whereas BCP-ALL was more frequently affected by mutation in genes involved in B-cell development. Integrating copy number alterations, somatic mutations and gene expression by RNA-sequencing revealed virtually all molecular subtypes originally defined in BCP-ALL to be present in BCP-LBL too, with only 7% of lymphomas that were not assigned to a subtype. Therefore, the results here described may pave the way for molecular risk adapted treatment protocols for BCP-LBL patients. KeypointsComprehensive molecular characterization of B-cell precursor lymphoblastic lymphoma allows molecular subtyping analogous to leukemias Compared to leukemias, lymphomas show more alterations in epigenetic modifiers and less in B-cell development genes

cancer biology↗

bioRxiv2023

nanoCLAMP potently neutralizes SARS-CoV-2 and protects K18-hACE2 mice from infection

Intranasal treatments, combined with vaccination, has the potential to slow mutational evolution of virusues by reducing transmission and replication. Here we illustrate the development of a SARS-CoV-2 receptor binding domain (RBD) nanoCLAMP and demonstrate its potential as an intranasally administered therapeutic. A multi-epitope nanoCLAMP was made by fusing a pM affinity single-domain nanoCLAMP (P2710) to alternate epitope binding nanoCLAMP, P2609. The resulting multimerised nanoCLAMP P2712 had sub-pM affinity for the Wuhan and South African (B.1.351) RBD (KD < 1 pM), and decreasing affinity for the Delta (B.1.617.2) and Omicron (B.1.1.529) variants (86 pM and 19.7 nM, respectively). P2712 potently inhibited ACE2:RBD interaction, suggesting its utility as a therapeutic. With an IC50 = 0.4 {+/-} 0.1 nM obtained from neutralization experiments using pseudoviral particles as well as patient cultured SARS-CoV-2 samples, nanoCLAMP P2712 protected K18-hACE2 mice from SARS-CoV-2 infection, reduced viral loads in the lungs and brains, and reduced associated upregulation of inflammatory cytokines and chemokines. Together, our findings warrant further investigation into the development of nanoCLAMPs as effective intranasally delivered COVID19 therapeutics.

bioengineering↗

bioRxiv2023

Integrin-alpha V beta 3 is a fundamental factor in medulloblastoma tumorigenicity and radioresistance: A new game for an old player

Medulloblastoma (MB) is the most frequent solid tumor in children, localized in the brains posterior fossa. Its standard of care comprises maximal resection surgery followed by craniospinal irradiation and chemotherapy. Despite a long-term survival rate of 70%, wide disparities among patients have been observed. Relevant targets for naive and recurrent MB are urgently needed. Primary and recurrent MBs are characterized by aggressive invasion into surrounding brain tissue, active angiogenesis, and radioresistance. Integrin-v{beta}3 was a major driver of these features in glioblastoma. Nevertheless, such observations have not yet been reported in MB. Integrin-v{beta}3 was found to be expressed in a subset of MB patients. We investigated the role of integrin-v{beta}3 using MB-derived cell lines with {beta}3-subunit depletion or overexpression both in vitro and in vivo. Radioresistant MB cell lines were generated and showed increased integrin-v{beta}3 expression, which correlated with increased susceptibility to pharmacological integrin-v{beta}3 inhibition with cilengitide, a competitive ligand mimetic. Finally, we conducted single-photon emission computed tomography (SPECT)/magnetic resonance imaging (MRI) studies on orthotopic models using a radiolabeled integrin-v{beta}3 ligand (99mTc-RAFT-RGD). This approach offers the prospect of a novel predictive imaging modality in MB. Altogether, our data pave the way for SPECT/MRI-based selection of a subpopulation of MB patients eligible for integrin-v{beta}3-directed therapies. SIGNIFICANCEThis study demonstrates integrin-v{beta}3s fundamental role in MB tumorigenicity and radioresistance and the effect of its expression on cilengitide functional activity.

cancer biology↗