Typologie d'actualités: Group Metal complexes and MRI

New imaging probe enables MRI detection of early-stage breast cancer tumors

Despite significant progress in cancer imaging and treatment over the years; early diagnosis, metastasis detection, and a better understanding of cancer progression remain an unmet clinical need. Molecular imaging can fulfil this need, but requires the design of contrast agents which target specific tumor biomarkers. Netrin-1 is an extracellular protein overexpressed in metastatic breast, and it is implicated in tumor progression, angiogenesis and appearance of metastasis and tumor aggressivity.

Reserachers of the team "Metal complexes and MRI", develop and validated in vivo the first Netrin-1 specific peptide-based multimodal probe.  A structural validation was performed by molecular docking, thanks to a collaboration CBM and Institute of Organic and Analytical Chemistry.

This probe enabled successful triple-negative metastatic breast tumor visualization namely at early development stage (tumor volume 0-50 mm3), by magnetic resonance imaging (MRI). Such peptide-based probes are molecular platforms allowing imaging by MRI or single photon emission tomography. This bimodal approach makes it possible to scan a wide range of target concentrations (nM to μM), enabling in vivo mapping of Netrin-1 in cancer murine models, at different tumor evolution stages.

References:
Clémentine Moreau, Tea Lukačević, Agnès Pallier, Julien Sobilo, Samia Aci-Sèche, Norbert Garnier, Sandra Même, Éva Tóth and Sara LacerdaPeptide-Conjugated MRI Probe Targeted to Netrin-1, a Novel Metastatic Breast Cancer Biomarker
Bioconjugate Chem. https://doi.org/10.1021/acs.bioconjchem.3c00558

Research on glioma (brain tumor) carried out at the CBM highlighted by CNRS Chimie

The use of different original NMR methods (MRI, 1H HR-MAS, 2D liquid NMR) made it possible to characterize a glioma model established in adult Drosophila and to reveal the therapeutic potential of a serotonin receptor for the treatment of these cancers.

Read the CNRS Chimie article.

Read the "Actualité chimique" article n° 492, 2024, February

Gliomas account for 50% of brain cancers and therefore constitute the most common brain tumors. Molecular alterations involved in adult gliomas have been identified and mainly affect tyrosine kinase receptors with amplification and/or mutation of the epidermal growth factor receptor (EGFR) and its associated signaling pathways. Several targeted therapies have been developed but current treatments remain ineffective for glioblastomas, the most severe forms. Thus, it is a priority to identify new pharmacological targets. Here, we used a Drosophila glioma model in adult, to characterize metabolic disturbances associated with glioma and assess the consequences of the serotonin 5-HT7 receptor expression on glioma development. First, by using in vivo Magnetic Resonance Imaging, we have shown that expression of the constitutively active forms of EGFR and PI3K in adult glial cells induced enlargement of brains. Then, we explored altered cellular metabolism by using High-Resolution Magic Angle Spinning NMR and 1H-13C Heteronuclear Single Quantum Coherence solution state. Discriminant metabolites identified highlight rewiring of metabolic pathways in glioma, and associated cachexia phenotypes. Finally, the expression of 5-HT7R in this model attenuates phenotypes associated with glioma development (brain enlargement and cachexia).

Article :
An adult Drosophila glioma model to highlight metabolic dysfunctions and evaluate the role of the serotonin 5-HT7 receptor as a potential therapeutic target.
Bertrand M, Szeremeta F, Hervouet‐Coste N, Sarou-Kanian V, Landon C, Morisset-Lopez S, Decoville M
The FASEB Journal. 2023 37:e23230. doi:10.1096/fj.202300783RR

The League Against Cancer supports research carried out at the CBM and the INEM

The committees of the Grand Ouest Cancer League bringing together Brittany, Pays de la Loire, Centre-Val de Loire and Poitou-Charentes pool their resources to support cancer researchers.

On Tuesday 7 February at the CBM, La Ligue contre le cancer officially presented a check for €146,000 to support 6 teams of researchers from the CBM and the INEM (Laboratory of Experimental and Molecular Immunology and Neurogenetics). The projects supported aim to quickly achieve concrete results for the benefit of patients.

The committees of Loiret (represented by its volunteer Administrator, Doctor Jean-Louis Vaur) and Eure-et-Loir (represented by its volunteer Vice-President Mr. Jacques Dautreme) were present. The Loir-et-Cher, Cher and Morbihan committees, which are also funders, could not be present but indicated that they were happy to be able to contribute to the financing of regional research.

Mr. Jean-Marc Schneider from La République du Center came to immortalize this moment by going around the table allowing everyone to present their project as well as the benefits and progress to come.

Eva Jakab Toth has received the “Rudolf Fabinyi” Prize of the Hungarian Chemical Society

Eva Jakab Toth, co-coordinator of the “Metal Complexes and MRI” team, has received the “Rudolf Fabinyi” Prize from the Hungarian Chemical Society.

This Prize, named after the founder and the first president of the Hungarian Chemical Society, is attributed to a chemist working abroad for his/her remarkable contribution to enhance the visibility of Hungarian chemical research. Eva Jakab Toth is the 10th person to receive this Prize.

The Prize ceremony took place on the 2nd Dec. 2022 in Debrecen, Hungary, followed by a scientific conference given by Eva Jakab Toth.

Bispidines and manganese: a winning couple

As an essential metal ion and an efficient relaxation agent, Mn2+ holds great promise as a substitute for Gd3+ in MRI contrast agent applications, if its stable and inert complexation can be achieved. To achieve this goal, the “Metal complexes and MRI” team of CBM and their collaborators from the University of Heidelberg, Germany, created a Mn2+ selective chelator by introducing four pyridine and one carboxylate donors on a bispidine skeleton. Thanks to a highly rigid and preorganized structure and perfect size-match for Mn2+, the new ligand L provides not only remarkably high thermodynamic stability, but also excellent selectivity over the major biological competitor Zn2+, as well as kinetic inertness. The unusual eight-coordinate structure of the Mn2+ complex, in contrast to the six-coordinate structure of the Zn2+ analogue, underlines that the coordination cavity is perfectly adapted for Mn2+, while it is too large for Zn2+. The MRI efficiency of this MnL complex is about 30% higher than that of typical Mn2+ systems. In vivo MRI experiments realized in control mice at a very low dose (0.02 mmol/kg) indicate good signal enhancement and fast renal clearance. Taken together, MnL is the first chelate that combines such excellent stability, selectivity, inertness and relaxation properties, all of primary importance for MRI use.

D. Ndiaye, P. Cieslik, H. Wadepohl, A. Pallier, S. Même, P. Comba, and É. Tóth, Mn2+ bispidine complex combining exceptional stability, inertness and MRI efficiency, J. Am. Chem. Soc. 2022, doi : 10.1021/jacs.2c10108
JACS spotlight sur cet article : https://pubs.acs.org/doi/pdf/10.1021/jacs.2c12719