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Larbouret, C.

Publications and source records attributed to Larbouret, C..

2 recordsLinked to original sources

Addressing multiple facets of ligand-receptor network inference including single-cell proteomics

Distinct ligand-receptor interaction (LRI) inference tools often produce markedly different results, and their performance can vary considerably across datasets. Indeed, performance is influenced by differences in experimental designs and dataset-specific features, making it difficult to establish a universal LRI tool. To address this challenge, we expanded our SingleCellSignalR Bioconductor package to provide an integrated framework that incorporates alternative scoring strategies and adjustable analytical depth. We motivate this choice through the analysis of two single-cell transcriptomics datasets that exemplify contrasting experimental designs. Leveraging the new framework flexibility, we present a detailed analysis of paired single-cell proteomics and transcriptomics data, providing, to our knowledge, the first direct comparison of LRI inference across these complementary modalities at single-cell resolution. Finally, we demonstrate how the same framework seamlessly accommodates additional underexplored data types from the LRI perspective, including patient-derived mouse xenografts and bulk RNA sequencing of upstream-sorted cell populations.

bioinformatics↗

Biasing HER4 Tyrosine Kinase Signaling with Antibodies: Induction of Cell Death by Antibody-Dependent HER4 Intracellular Domain Trafficking

HER4 isoforms have oncogenic or tumor suppressor functions depending on their susceptibility to proteolytic cleavage and HER4 Intracellular Domain (4ICD) translocation. Here, we report that the NRG1 tumor suppressor mechanism through the HER4 JMa/CYT1 isoform can be mimicked by the agonist anti-HER4 antibody C6. NRG1 induced cleavage of poly(ADP-ribose) polymerase (PARP) and sub-G1 DNA fragmentation, and also reduced the metabolic activity of HER3-negative/HER4-positive cervical (C-33A) and ovarian (COV318) cancer cells. This effect was confirmed in HER4 JMa/CYT1-, but not JMa/CYT2-transfected BT549 triple-negative breast cancer cells. NRG1 favored 4ICD cleavage and retention in mitochondria in JMa/CYT1-transfected BT549 cells, leading to Reactive Oxygen Species (ROS) production through mitochondrial depolarization. Similarly, the anti-HER4 antibody C6, which binds to a conformational epitope located on aa 575-592 and 605-620 of HER4 domain IV, induced 4ICD cleavage and retention in mitochondria, and mimicked NRG1-mediated effects on PARP cleavage, ROS production, and mitochondrial membrane depolarization in cancer cells. In vivo, C6 reduced growth of COV434 and HCC187 tumor cell xenografts in nude mice. Biasing 4ICD trafficking to mitochondria with anti-HER4 antibodies to mimic NRG1 suppressor functions could be an alternative anti-cancer strategy.

cancer biology↗