Biology subjects

Corsi, F.

Publications and source records attributed to Corsi, F..

8 recordsLinked to original sources

bioRxiv2025

Membrane Sensing Peptides -Enhanced SiMoA Platform for the Detection of HER2 on Extracellular Vesicles in Metastatic Breast Cancer Patients

Extracellular vesicles (EVs) offer a promising avenue for non-invasive, real-time monitoring of metastatic breast cancer (mBC), but clinical application as a liquid biopsy is hindered by their heterogeneity and low abundance. Here we present a Single Molecule Array (SiMoA) platform enhanced by membrane sensing peptides (MSP) for the highly sensitive detection of HER2 on EV membranes (EVs-HER2) and general EVs population (CD9+) directly from plasma samples of mBC patients. The MSP-based SiMoA assay demonstrated superior sensitivity and specificity compared to conventional antibody-based assays, allowing the detection of lower amounts of EVs and discriminating EVs derived from breast cancer patient-derived organoids (BC-PDO) from healthy control-derived organoids (HC-PDO). Concerning the analysis of EVs in plasma samples (n=49 mBC patients, n=30 healthy controls), we observed significantly lower CD9+ EVs levels in mBC patients relative to healthy controls, a trend consistently confirmed across assays. Notably, EVs-HER2 levels were significantly enriched in HER2-positive patients and correlated with clinical HER2 status assessed by immunohistochemistry. Besides, lower CD9+ EVs levels were associated with poorer clinical outcomes, highlighting the potential prognostic utility of EV quantification. Our findings underscore the potential of MSP-enhanced SiMoA platforms for accurate, minimally invasive monitoring of EVs-HER2 in mBC and for monitoring CD9+ EVs levels to assess disease progression.

biochemistry↗

bioRxiv2025

Conformational asymmetry of replicated human chromosomes

DNA replication creates two sister chromatids that must acquire specific three-dimensional conformations to support genome function and stability. This organization is largely mediated by cohesin complexes, which extrude intra-chromosomal loops and link two chromatids, thus forming "chromatid cohesion". Although sister chromatids are genetically identical, the replication process is intrinsically asymmetric: each chromatid inherits a different parental DNA strand, while the new strands are synthesized using distinct "leading" and "lagging" mechanisms of the replication fork. Whether and how this molecular asymmetry impacts higher-order chromatin organization remains unknown. Using sister-chromatid-sensitive Hi-C, strand-specific FISH, and polymer modeling, we reveal a consistent, genome-wide shift in sister chromatid alignment, biased along the 5'-3' direction of the inherited strands. This shift persists without loop extrusion but is lost upon disruption of cohesion, implicating cohesive cohesins in maintaining the displacement. Polymer simulations indicate that a modest ([~]100 kb) misalignment of "cohesive" cohesins is responsible for the observed asymmetry. We propose two mechanistic models that explain how this displacement arises from replication fork asymmetry: either through the dislocation of cohesin during replication or through the asymmetric anchoring and subsequent random sliding of cohesin pairs. These findings reveal a previously unrecognized chromosome-scale asymmetry in sister chromatid organization, which has implications for homology search during DNA repair.

molecular biology↗

bioRxiv2025

Red Blood Cell-derived Extracellular Vesicles enable Cisplatin and Cetuximab Synergistic Therapy against Triple-Negative Breast Cancer

BackgroundTriple-negative breast cancer is an aggressive breast cancer subtype characterized by the absence of human epidermal growth factor receptor 2, estrogen and progesterone receptors, limiting targeted therapy options. Cisplatin, a chemotherapeutic agent, induces DNA damage and exhibits some efficacy against triple-negative breast cancer, but its effectiveness is often reduced by chemoresistance and systemic toxicity. A very promising strategy to augment cisplatin treatment can be based on combining it with the biologic Cetuximab, an epidermal growth factor receptor inhibitor, which boosts cisplatin efficacy by inducing ferroptosis. ResultsTo optimize this strategy in a biocompatible and precise manner, we developed a nanoplatform based on red blood cell-derived extracellular vesicles for the combined delivery of Cetuximab and cisplatin, enabling immune evasion, and the possibility of autologous personalization and GMP-compliant production. Owing to their DNA-free lumen and lack of EGFR, RBC-EVs preserve cisplatin activity and prevent interference with cetuximab. This formulation enhances cisplatins cytotoxicity by up to 50%, as shown in vitro and in patient-derived organoids. It effectively reduces chemoresistance by downregulating hypoxia-related genes and promoting ferroptosis, additionally, it improves cisplatins cytotoxic effects while reducing hemotoxicity compared to the administration of free cisplatin. ConclusionsThese findings highlight the potential of red blood cell-derived extracellular vesicles as a biocompatible delivery system enabling combined therapy and offering a promising strategy to overcome current limitations in TNBC treatment.

cell biology↗

bioRxiv2024

Exploring Breast Cancer-Related Biochemical Changes in Circulating Extracellular Vesicles Using Raman Spectroscopy

Extracellular vesicles (EVs) are a subgroup of the circulating particles, released by cells in both normal and diseased states, carrying active biomolecules. They have gained significant attention as potential cancer biomarkers, particularly in breast cancer (BC). Previous research showed variations in EVs content and quantity between BC patients and healthy controls (HC). However, studying EVs biochemical profile remains challenging due to their low abundance and complex composition. Additionally, EVs may interact with other plasma components, like lipoproteins (LPs), forming a so called "biomolecular corona" that further complicates their analysis. Here, Raman spectroscopy (RS) is proposed as a fast tool to obtain the biochemical profile of circulating EVs in the context of BC. RS was employed to differentiate various extracellular particles (EPs) in blood, including LPs and EVs. The study also evaluated RSs capability to quantify major classes of biomolecules and compared these results with those obtained by traditional biochemical assays. Finally, compositional differences in large EVs (lEVs) and small EVs (sEVs) were assessed between 30 HC and 34 BC patients. RS revealed the existence of distinct biochemical signatures associated with BC, highlighting increased levels of nucleic acids and lipids in the BC group.

biophysics↗

bioRxiv2024

H105A peptide eye drops promote photoreceptor survival in murine and human models of retinal degeneration

Photoreceptor death causes blinding inheritable retinal diseases, such as retinitis pigmentosa (RP). As disease progression often outpaces therapeutic advances, finding effective treatments is urgent. This study focuses on developing a targeted approach by evaluating the efficacy of small peptides derived from pigment epithelium-derived factor (PEDF), known to restrict common cell death pathways associated with retinal diseases. Peptides with affinity for the PEDF receptor, PEDF-R, (17-mer and H105A) delivered via eye drops reached the retina, efficiently promoted photoreceptor survival, and improved retinal function in RP mouse models based on both the rd10 mutation and the rhodopsin P23H mutation. Additionally, intravitreal delivery of AAV-H105A vectors delayed photoreceptor degeneration in the latter RP mouse model. Furthermore, peptide H105A specifically prevented photoreceptor death induced by oxidative stress, a contributing factor to RP progression, in human retinal organoids. This promising approach for peptide eye drop delivery holds significant potential as a therapeutic for preventing photoreceptor death in retinal disorders, offering a high safety profile, low invasiveness and multiple delivery options. One Sentence SummaryNeurotrophic PEDF peptides delivered as eye drops preserve photoreceptor viability, morphology, and function in models of human retinal diseases.

neuroscience↗

bioRxiv2024

Forecasting Dengue Fever in Brazil Using Multimodal Data, Including Climate Data

Dengue fever is a major tropical disease transmitted by Aedes mosquitoes. Dengue affects more than 120 countries with highly variable year to year infection rates. Despite high variability, dengue has a clear relationship to climate factors and human demography. Global trends to higher temperatures and greater disorderly urban development are increasing the scale and scope of dengue risk. Dengue has complex human immunity with 4 known serotypes that make multiple infections possible. Accurate forecasting of dengue fever would allow for appropriate interventions and improved public health outcomes. We demonstrate, GeoSeeq Dengue, a forecasting model for dengue fever in Brazil. GeoSeeq Dengue predicts dengue outbreaks monthly in 5,570 Brazilian municipalities at 1, 3, and 6 months ahead of the outbreak. Model accuracy compares favorably to a historical baseline model, making it a promising model for informing public health response. We evaluate how different types of input variables effect model accuracy and explore how this model could be adapted to other countries. This model could inform public health responses to dengue including targeting vector control programs, public health education messaging, and the newly launched dengue vaccine rollout.

bioinformatics↗

bioRxiv2021

Raman spectroscopy on microcalcifications reveals peculiar differences between male and female breast cancer

Microcalcifications (MCs) are important disease markers for breast cancer. Many studies were conducted on their characterization in female breast cancer (FBC), but no information is available on their composition in male breast cancer (MBC). Raman spectroscopy (RS) is a molecular spectroscopy technique that can explore the biochemical composition of MCs rapidly and without requiring any staining protocol. We here compared, by Raman spectroscopy, the MCs identified on breast cancer pieces from male and female patients. In this study, we used Raman spectroscopy to analyse 41 microcalcifications from 5 invasive MBC patients and 149 MCs from 14 invasive FBC patients. Our findings show that hydroxyapatite is the most abundant type of calcium both in MBC and FBC. However, some differences in the amount and distribution of calcium minerals are present between the two groups. Besides, we observed that MCs in MBC have a higher amount of organic material (collagen) than FBC. This study provides the first overview of the composition of microcalcifications present in MBC and suggests that they have several specific features. Our result support the need for studies specifically designed to the understanding of MBC.

cancer biology↗

bioRxiv2019

Multiple protein-DNA interfaces unravelled by evolutionary information, physico-chemical and geometrical properties

The usage made of protein surfaces by nucleic acids still remains largely unknown, due to the lack of available structural data and the inherent complexity associated to protein surface deformability and evolution. In this work, we present a method that contributes to decipher such complexity by predicting protein-DNA interfaces and characterizing their properties. It relies on three biologically and physically meaningful descriptors, namely evolutionary conservation, physico-chemical properties and surface geometry. We carefully assessed its performance on several hundreds of protein structures. We achieve a higher sensitivity compared to state-of-the-art methods, and similar precision. Importantly, we show that our method is able to unravel hidden binding sites by applying it to unbound protein structures and to proteins binding to DNA via multiple sites and in different conformations. It is implemented as a fully automated tool, [Formula], freely accessible at: http://www.lcqb.upmc.fr/JET2DNA. We also provide a new reference dataset of 187 protein-DNA complex structures, representative of all types of protein-DNA interactions, along with a subset of associated unbound structures: http://www.lcqb.upmc.fr/PDNAbenchmarks.

bioinformatics↗