Targeting the activated allosteric conformation of the endothelin receptor B in melanoma with an antibody-drug conjugate: mechanisms and therapeutic efficacy.

Background: Endothelin 1 receptors are one of the drivers of tumor progression in many cancers. Inhibition of their signaling pathways with antagonist drugs has been the subject of numerous clinical trials, but the results have not met expectations probably due to the high endothelin concentrations in the tumor microenvironment and their unusually high affinity for their receptors.

Methods: We previously reported the rendomab B49 antibody (RB49) exhibiting a preferential affinity for the activated conformation of human endothelin B receptor (ET), not displaced by high endothelin levels, and without any pharmacological properties that could inhibit the division of melanoma cells.

Preoperative PET imaging and fluorescence-guided surgery of human glioblastoma using dual-labeled antibody targeting ET receptors in a preclinical mouse model: A theranostic approach.

Glioblastoma (GBM) poses significant challenges regarding complete tumor removal due to its heterogeneity and invasiveness, emphasizing the need for effective therapeutic options. In the last two decades, fluorescence-guided surgery (FGS), employing fluorophores such as 5-aminolevulinic acid (5-ALA) to enhance tumor delineation, has gained attraction among neurosurgeons. However, some low-grade tumors do not show any accumulation of the tracers, and the lack of patient stratification represents an important limitation.

A Fab of trastuzumab to treat HER2 overexpressing breast cancer brain metastases.

Despite major therapeutic advances for two decades, including the most recently approved anti-HER2 drugs, brain metastatic localizations remain the major cause of death for women with metastatic HER2 breast cancer. The main reason is the limited drug passage of the blood-brain barrier after intravenous injection and the significant efflux of drugs, including monoclocal antibodies, after administration into the cerebrospinal fluid. We hypothesized that this efflux was linked to the presence of a FcRn receptor in the blood-brain barrier.

The functionality of a therapeutic antibody candidate restored by a single mutation from proline to threonine in the variable region.

mAbs play an essential role in the therapeutic arsenal. Our laboratory has patented the Rendomab-B49 mAb targeting the endothelin B receptor (ET). This G protein-coupled receptor plays a driving role in the progression of numerous cancers.

Synthesis and Preclinical Fluorescence Imaging of Dually Functionalized Antibody Conjugates Targeting Endothelin Receptor-Positive Tumors.

For the past two decades, the emerging role of the endothelin (ET) axis in cancer has been extensively investigated, and its involvement in several mechanisms described as "hallmarks of cancer" has clearly highlighted its potential as a therapeutic target. Despite the growing interest in finding effective anticancer drugs, no breakthrough treatment has successfully made its way to the market. Recently, our team reported the development of a new immuno-positron emission tomography probe targeting the ET A receptor (ET, one of the ET receptors) that allows the successful detection of ET glioblastoma, paving the way for the elaboration of novel antibody-based strategies.

Neurofilament light chain in plasma as a sensitive diagnostic biomarker of peripheral neurotoxicity: In Vivo mouse studies with oxaliplatin and paclitaxel - NeuroDeRisk project.

Identifying compounds that are neurotoxic either toward the central or the peripheral nervous systems (CNS or PNS) would greatly benefit early stages of drug development by derisking liabilities and selecting safe compounds. Unfortunately, so far assays mostly rely on histopathology findings often identified after repeated-dose toxicity studies in animals. The European NeuroDeRisk project aimed to provide comprehensive tools to identify compounds likely inducing neurotoxicity.

Integrative Analysis of Proteomics and Transcriptomics Reveals Endothelin Receptor B as Novel Single Target and Identifies New Combinatorial Targets for Multiple Myeloma.

Despite the recent introduction of next-generation immunotherapeutic agents, multiple myeloma (MM) remains incurable. New strategies targeting MM-specific antigens may result in a more effective therapy by preventing antigen escape, clonal evolution, and tumor resistance. In this work, we adapted an algorithm that integrates proteomic and transcriptomic results of myeloma cells to identify new antigens and possible antigen combinations.

ImmunoPET imaging-based pharmacokinetic profiles of an antibody and its Fab targeting endothelin A receptors on glioblastoma stem cells in a preclinical orthotopic model.

Background: The resistance of glioblastoma stem cells (GSCs) to treatment is one of the causes of glioblastoma (GBM) recurrence. Endothelin A receptor (ET) overexpression in GSCs constitutes an attractive biomarker for targeting this cell subpopulation, as illustrated by several clinical trials evaluating the therapeutic efficacy of endothelin receptor antagonists against GBM. In this context, we have designed an immunoPET radioligand combining the chimeric antibody targeting ET, chimeric-Rendomab A63 (xiRA63), with Zr isotope and evaluated the abilities of xiRA63 and its Fab (ThioFab-xiRA63) to detect ET tumors in a mouse model xenografted orthotopically with patient-derived Gli7 GSCs.

Investigating the utility of minimized sample preparation and high-resolution mass spectrometry for quantification of monoclonal antibody drugs.

Determination of the pharmacokinetic (PK) properties of therapeutic monoclonal antibodies (mAbs) is essential for their successful development as drugs. For this purpose, besides the traditional ligand binding assay (LBA), LC-MS/MS method using low resolution mass spectrometers (e.g.

Antibodies targeting human endothelin-1 receptors reveal different conformational states in cancer cells.

The endothelin axis (endothelins and their receptors) is strongly involved in physiological and pathological processes. ET-1 plays a crucial role in particular in tumor diseases. Endothelin-1 receptors (ET(A) and ET(B)) are deregulated and overexpressed in several tumors such as melanoma and glioma.

Optimization of pegylated iron oxide nanoplatforms for antibody coupling and bio-targeting.

PEGylation has been established as a valuable strategy to minimize nanoparticle clearance by the reticulo-endothelial system due to hydrophilicity and steric repulsion of PEG chains. In this study we functionalized superparamagnetic iron oxide nanoparticle surface with two PEG differing in their length (n = 23 and 44) and terminal functionality, COOH and CH. By varying the ratio of the two different PEG, we optimized the molecular architecture of the nanoplatform to obtain maximum stability and low toxicity under physiological conditions.

Refolding of Aggregation-Prone ScFv Antibody Fragments Assisted by Hydrophobically Modified Poly(sodium acrylate) Derivatives.

ScFv antibody fragments are a promising alternative to full-length antibodies for both therapeutic and diagnosis applications. They can be overexpressed in bacteria, which enables easy large scale production. Since scFv are artificial constructs, they are poorly soluble and prone to aggregation, which makes them difficult to manipulate and to refold.

Rendomab B4, a monoclonal antibody that discriminates the human endothelin B receptor of melanoma cells and inhibits their migration.

Metastatic melanoma is an aggressive cancer with a poor prognostic, and the design of new targeted drugs to treat melanoma is a therapeutic challenge. A promising approach is to produce monoclonal antibodies (mAbs) against the endothelin B receptor (ETB), which is known to be overexpressed in melanoma and to contribute to proliferation, migration and vasculogenic mimicry associated with invasiveness of this cancer. We previously described rendomab-B1, a mAb produced by DNA immunization.

Endothelin B receptors targeted by iron oxide nanoparticles functionalized with a specific antibody: toward immunoimaging of brain tumors.

In this study, we developed a new bimodal imaging tracer directed against endothelin B receptors to detect brain cancer cells using MRI and to assist tumor surgery with fluorescence imaging. This was achieved by coating the surface of iron oxide nanoparticles with a monoclonal antibody, rendomab-B1, labeled with a fluorescent dye. Two nanoplatforms were elaborated differing by the average number of antibodies grafted onto the nanoparticle surface.

Prevention of thermally induced aggregation of IgG antibodies by noncovalent interaction with poly(acrylate) derivatives.

Prevention of thermal aggregation of antibodies in aqueous solutions was achieved by noncovalent association with hydrophobically modified poly(acrylate) copolymers. Using a polyclonal immunoglobin G (IgG) as a model system for antibodies, we have studied the mechanisms by which this multidomain protein interacts with polyanions when incubated at physiological pH and at temperatures below and above the protein unfolding/denaturation temperature, in salt-free solutions and in 0.1 M NaCl solutions.

High level prokaryotic expression of anti-Müllerian inhibiting substance type II receptor diabody, a new recombinant antibody for in vivo ovarian cancer imaging.

Prescription of therapeutic antibodies has radically modified the prognosis of some important diseases. However, the very high cost of these new drugs is a problem for public health organizations, which require assessment of the effectiveness of the antibody for each patient before beginning or during the treatment. In vivo immunoimaging is particularly well adapted to meet this demand.

Ontogeny of aquaporins in human fetal membranes.

It has been proposed that four members of the aquaporin family (AQPs 1, 3, 8, and 9) are involved in the control of amniotic fluid (AF) homeostasis, as illustrated by their differential expression patterns in normal and pathological human term fetal membranes. However, there are no data available to date on their ontogeny throughout pregnancy. Our objective was to determine spatiotemporal expression profiles of the mRNA and proteins of all 13 members of this transmembrane channel family.

Pharmacological and structural characterization of long-sarafotoxins, a new family of endothelin-like peptides: Role of the C-terminus extension.

Long-sarafotoxins (l-SRTXs) have recently been identified in both the venom of Atractaspis microlepidota and that of Atractaspis irregularis. They are characterized by different C-terminus extensions that follow the invariant Trp21, which plays a crucial role in endothelin-receptor binding. We initially determined the toxicity and three-dimensional structures of two chemically synthesized l-SRTXs that have different C-terminus extensions, namely SRTX-m (24 aa, including extension "D-E-P") and SRTX-i3 (25 aa, including extension "V-N-R-N").

[Implications of retinoid pathway in human fetal membranes: study of target genes].

Retinoids (active derivatives of vitamin A) were already demonstrated to be important morphogenes and their implication at the placental and fetal level was already established. A new field of research is now developed in order to show their role on fetal membranes constituted by amnion and chorion. To describe the role of retinoids on these membranes, our studies were focused on target gene research.

Immuno-mass spectrometry assay of EPI-HNE4, a recombinant protein inhibitor of human elastase.

In order to increase the sensitivity of liquid chromatography/mass spectrometry (LC/MS) assays of recombinant proteins for pharmacokinetics studies, we have developed an immuno-mass spectrometry assay for EPI-hNE4, a 6237 Da protein currently developed for respiratory distress syndromes. After immunocapture of the analyte in human plasma with magnetic beads coated with anti-EPI-hNE4 antibodies, the intact protein was eluted and separated in reversed-phase LC and then analysed by tandem mass spectrometry (MS/MS) in selected reaction monitoring (SRM) mode. The problem of analytical interference due to endogenous binding antibodies was addressed by successive steps of acidification and neutralisation before immunocapture.

Pharmacokinetics of DTPA entrapped in conventional and long-circulating liposomes of different size for plutonium decorporation.

The aim of the present study was to develop an efficient DTPA liposome formulation designed for plutonium decorporation. DTPA was encapsulated in conventional (CL) and polyethylene glycol-coated stealth liposomes (SL) prepared by extrusion followed by the freeze-thawing method and sizing from around 100 to 800 nm. DTPA encapsulation percentages were approximately 30% in CL of any size but dropped from 48% to 7% as the diameter of SL was reduced.

Effect of milrinone on echocardiographic parameters after single dose in Beagle dogs and relationship with drug-induced cardiotoxicity.

The aim of this study was to further investigate the mechanism of development of cardiac lesions occurring under treatment with milrinone in dogs, by using echocardiography for assessing the effects of this drug on cardiac function. Milrinone is a cAMP phosphodiesterase 3 inhibitor having positive inotropic and vasodilatory effects. We treated groups of three dogs with milrinone at a single dose of 0.

Subcommissural organ/Reissner's fiber complex: characterization of SCO-spondin, a glycoprotein with potent activity on neurite outgrowth.

In the developing vertebrate nervous system, several proteins of the thrombospondin superfamily act on axonal pathfinding. By successive screening of a SCO-cDNA library, we have characterized a new member of this superfamily, which we call SCO-spondin. This extracellular matrix glycoprotein of 4,560 amino acids is expressed and secreted early in development by the subcommissural organ (SCO), an ependymal differentiation located in the roof of the Sylvian aqueduct.

SCO-spondin and RF-GlyI: two designations for the same glycoprotein secreted by the subcommissural organ.

SCO-spondin and RF-GlyI are two designations for cDNAs strongly expressed in the bovine subcommissural organ (SCO), characterized, respectively, in 1996 and 1998 by two different research groups. Because both cDNAs were partial sequences and exhibited close similarities in their nucleotide and deduced amino acid sequences, it was thought that they might be part of the same encoding sequence. To find out, we performed 3'RACE using a SCO-spondin-specific upstream primer.