Biology subjects

Barbi, M.

Publications and source records attributed to Barbi, M..

7 recordsLinked to original sources

bioRxiv2026

Comprehensive Molecular Characterization of High-Grade Endometrial Cancer in an Ancestrally-Diverse Cohort

Endometrial cancer (EC) exhibits one of the most striking racial disparities in oncology with black women disproportionately affected by aggressive high-grade subtypes that have poorer outcomes. While social and environmental factors undoubtedly contribute, the molecular underpinnings of these disparities remain critically understudied. To bridge this knowledge gap, we performed matched tumor-normal whole-genome sequencing and tumor transcriptome sequencing on 71 predominantly high-grade EC patient samples from an ancestrally diverse cohort of women recruited at a large hospital system in the New York metropolitan area. Our analysis characterized the germline and somatic mutation landscape, identifying ancestry-associated molecular differences. Notably, focal amplification of the EVI1 transcription factor (encoded at the MECOM locus) was significantly more frequent in African ancestry patients and associated with poorer clinical outcomes in an external validation cohort. Additionally transcriptome analysis revealed decreased CD8+ T cell infiltration with increasing African ancestry, suggesting tumor immune microenvironment differences with potential therapeutic implications. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=163 SRC="FIGDIR/small/721962v1_ufig1.gif" ALT="Figure 1"> View larger version (63K): org.highwire.dtl.DTLVardef@12125b9org.highwire.dtl.DTLVardef@133c787org.highwire.dtl.DTLVardef@707af0org.highwire.dtl.DTLVardef@97615c_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIThis study represents the most ancestrally diverse whole-genome sequencing characterization of high-grade endometrial cancer, with 62% of patients of African ancestry. C_LIO_LIMECOM focal amplification preferentially targets the oncogenic short isoform (EVI1) and is more frequent in patients of African ancestry. C_LIO_LIAfrican ancestry is associated with reduced CD8+ T cell infiltration and differential activation of immune and metabolic pathways in copy-number high endometrial tumors. C_LI

cancer biology↗

bioRxiv2026

A Single-Cell Atlas of Uterine Carcinosarcoma from Diverse Ancestries

Uterine carcinosarcoma (UCS) is an aggressive endometrial cancer defined by coexisting malignant epithelial and mesenchymal components, rapid metastatic dissemination, and poor therapeutic response. However, its cellular ecosystem remains poorly resolved, particularly in patients of African ancestry who are underrepresented in genomic datasets despite a disproportionate disease burden. Here, we generated a single-cell atlas of 15 primary and metastatic UCS specimens from a diverse cohort of 13 patients enriched for African ancestry, integrated with whole-genome sequencing. Malignant cells exhibited epithelial-like, mesenchymal-like, transitional, and stem/progenitor-like states within individual tumors that mapped to patient-specific copy number-defined subclones and RNA-velocity trajectories, supporting metaplastic state transitions. Compared to normal endometrium, primary tumors were enriched for epithelial-mesenchymal-transition (EMT), mTORC1, and glycolytic programs, whereas matched metastases show enhanced TNF-NF{kappa}B-associated invasive programs. The tumor microenvironment contained immunosuppressive myeloid states and diverse cancer-associated fibroblast (CAF) subsets, including pericyte-like and matrix-remodeling subsets that act as predicted communication hubs through chemokine and immune-checkpoint circuits. We found a CAF-centered CCL2-CXCL1/2-IL10 module linked to CD8 T-cell dysfunction and a TIGIT-CD96-PVR checkpoint module. These data define the UCS cellular ecosystem in which malignant plasticity is coupled to stromal-immune cell remodeling in a patient cohort of enriched ancestries and nominate stromal-immune axes for further therapeutic investigation.

cancer biology↗

bioRxiv2026

A Patient-derived Organoid Platform for Uterine Carcinosarcoma that Emulates Disease Characteristics

Uterine carcinosarcoma (UCS) is a rare but extremely lethal endometrial cancer that metastasizes early and resists current treatment modalities. It is biphasic, built from malignant epithelial and mesenchymal cells. Genomic studies indicate that these tumors are clonal, and that the mesenchymal cells arise from the epithelial cells through cancer cell plasticity. This biology has been hard to study, because faithful patient-derived models are scarce. The gap is widened by inequity. Women of African ancestry carry the greatest burden of UCS, yet are underrepresented in existing models. To address this, we established patient-derived organoids (PDOs) from an ancestrally inclusive UCS cohort, alongside matched normal endometrial PDOs. The organoids reproduced the biphasic histology of the original tumors. Across four sequencing platforms, they retained the tumor mutation and copy-number landscape, remained stable across passages, and expanded for up to 28 months. At single-cell resolution, UCS PDOs captured both malignant compartments and traced continuous transcriptional trajectories along the epithelial-to-mesenchymal axis, capturing patient-specific cancer cell plasticity. The models also nominated candidate vulnerabilities in proof-of-concept therapeutic testing. UCS PDOs were enriched for CREB-family transcriptional programs, and CREB inhibition reduced their viability. Combined FGFR and YAP inhibition outperformed either agent alone. Together, this work delivers a histologically, genomically, and transcriptionally faithful, ancestrally inclusive, and lineage-resolved UCS organoid platform for studying cancer cell plasticity and its vulnerabilities in an aggressive and inequitably burdened cancer.

cancer biology↗

bioRxiv2024

Smc5/6 association with microtubules controls dynamic pericentromeric chromatin folding

Centromeres and pericentromeres are specialized chromatin regions essential for accurate chromosome segregation. Smc5/6, which localizes at pericentromeres, can bind microtubules, yet its role in chromatin folding is unclear. Here, we investigate the functional relevance of Smc5/6- microtubule binding in yeast, by targeting two lysines (K624, K631) within the Smc5 hinge domain known to mediate this binding. Using high-temporal-resolution imaging, polymer modelling, and in vitro approaches with a separation-of-function mutant smc5-2KE, we demonstrate that microtubules binding by Smc5/6 constrains chromatin dynamics and promotes pericentromeric folding. The smc5-2KE mutant, combined with a hypomorphic kinetochore mutant (Mtw1-3xGFP), leads to spindle and cytokinesis defects and triggers the spindle checkpoint. Furthermore, homologous recombination repair in pericentromeres is compromised. Overall, our findings indicate that Smc5/6 - microtubules association safeguard pericentromeric architecture and genome stability during mitosis.

cell biology↗

bioRxiv2023

Spectral-based detection of chromatin loops in multiplexed super-resolution FISH data

Involved in mitotic condensation, interaction of transcriptional regulatory elements or isolation of structural domains, understanding loop formation is becoming a paradigm in the deciphering of chromatin architecture and its functional role. Despite the emergence of increasingly powerful genome visualization techniques, the high variability in cell populations and the randomness of conformations still make loop detection a challenge. We introduce a new approach for determining the presence and frequency of loops in a collection of experimental conformations obtained by multiplexed super-resolution imaging. Based on a spectral approach, in conjunction with neural networks, this method offers a powerful tool to detect loops in large experimental data sets, both at the population and single cell level. The methods performance is confirmed by applying it to recently published experimental data, where it provides a detailed and statistically quantified description of the global architecture of the chromosomal region under study.

biophysics↗

bioRxiv2021

Assessing the polymer coil-globule state from the very first spectral modes

The determination of the coil-globule transition of a polymer is generally based on the reconstruction of scaling laws, implying the need for samples from a rather wide range of different polymer lengths N. The spectral point of view developed in this work allows for a very parsimonious description of all the aspects of the finite-size coil-globule transition on the basis of the first two Rouse (cosine) modes only, shedding new light on polymer theory. Capturing the relevant configuration path features, the proposed approach enables to determine the state of a polymer without the need of any information about the polymer length or interaction strength. Importantly, we propose an experimental implementation of our analysis that can be easily performed with modern fluorescent imaging techniques, and would allow differentiation of coil or globule conformations by simply recording the positions of three discernible loci on the polymer.

biophysics↗

bioRxiv2018

Polymer coil-globule phase transition is a universal folding principle of Drosophila epigenetic domains

BackgroundLocalized functional domains within chromosomes, known as topologically associating domains (TADs), have been recently highlighted. In Drosophila, TADs are biochemically defined by epigenetic marks, this suggesting that the 3D arrangement may be the \"missing link\" between epigenetics and gene activity. Recent observations (Boettiger et al., Nature 2016) provide access to structural features of these domains with unprecedented resolution thanks to super-resolution experiments. In particular, they give access to the distribution of the radii of gyration for domains of different linear length and associated with different transcriptional activity states: active, inactive or repressed. Intriguingly, the observed scaling laws lack consistent interpretation in polymer physics.\n\nResultsWe develop a new methodology conceived to extract the best information from such super-resolution data by exploiting the whole distribution of gyration radii, and to place these experimental results on a theoretical framework. We show that the experimental data are compatible with the finite-size behavior of a self-attracting polymer. The same generic polymer model leads to quantitative differences between active, inactive and repressed domains. Active domains behave as pure polymer coils, while inactive and repressed domains both lie at the coil-globule crossover. For the first time, the \"colo-specificity\" of both the persistence length and the mean interaction energy are estimated, leading to important differences between epigenetic states.\n\nConclusionsThese results point toward a crucial role of criticality to enhance the system responsivity, resulting in both energy transitions and structural rearrangements. We get strong indications that epigenetically induced changes in nucleosome-nucleosome interaction can cause chromatin to shift between different activity states.

biophysics↗