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Biology subjects

Barelli, C.

Publications and source records attributed to Barelli, C..

3 recordsLinked to original sources

Human basal radial glia morphotypes are transcriptionally distinct and exhibit different cell fate determination

Basal radial glia (bRG) are key neural progenitors driving human neocortical expansion. They exhibit remarkable morphological heterogeneity, yet the stability and functional significance of their distinct morphotypes remains unclear. Using human cortical brain organoids combined with long-term live imaging and morphology-resolved spatial transcriptomics (CellShape-seq), we show that bRG morphotypes display distinct morphodynamic behaviors, proliferative capacities and transcriptional profiles. While bifurcated bRG remodel extensively during mitosis to produce morphologically diverse progeny, multipolar cells are most morphologically flexible during interphase. Multipolar bRG further show the greatest proliferative capacity and the transcriptional signature related to progenitor state. Bifurcated bRG are least proliferative and are enriched for the multifunctional gene expression regulator YBX1. Pharmacological inhibition of YBX1 depletes bifurcated bRG, reduces neurogenesis, and promotes glial commitment. Our findings link progenitor morphology, gene expression and fate, providing a framework for understanding the cellular logic of human cortical development.

neuroscience↗

Glioblastoma stem cell morphotypes convey distinct cell states and clinically relevant functions

Glioblastoma (GBM) is an aggressive brain tumor and an unmet clinical need due to its invasiveness and therapy-resistance. These features are driven by glioblastoma stem cells (GSCs), which exhibit remarkable functional heterogeneity. However, GSC transcriptional profiling alone cannot predict clinically relevant behaviors. Here, we developed CellShape-seq, a spatial transcriptomics platform that integrates cell morphology with transcriptome. This identified three GSC morphoclasses corresponding to distinct transcriptomic states and functions: (1) nonpolar cells show differentiation and therapy sensitivity, (2) elongated cells are invasive, and (3) multipolar cells form intercellular networks. Importantly, chemoresistance is morphoclass-specific: elongated GSCs depend on YAP/TEAD1 signaling, while multipolar GSCs rely on gap junction-mediated networks. Targeting these vulnerabilities with specific inhibitors sensitized resistant GSC morphoclasses to temozolomide (TMZ) in patient-derived organoids. Our findings demonstrate that morphology provides critical insights into GSC behavior and establish a rationale for morphology-informed therapies to overcome resistance and improve outcomes in GBM. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=85 SRC="FIGDIR/small/644884v2_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@141e698org.highwire.dtl.DTLVardef@18a238corg.highwire.dtl.DTLVardef@23ef62org.highwire.dtl.DTLVardef@1390c07_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

Morphoregulatory ADD3 underlies glioblastoma growth and formation of tumor-tumor connections

Glioblastoma is a major unmet clinical need characterized by striking inter- and intra-tumoral heterogeneity and a population of glioblastoma stem cells (GSCs), conferring aggressiveness and therapy resistance. GSCs communicate through a network of tumor-tumor connections (TTCs), including nanotubes and microtubes, promoting tumor progression. However, very little is known about the mechanisms underlying TTC formation and overall GSC morphology. As GSCs closely resemble neural progenitor cells during neurodevelopment, we hypothesised that GSCs morphological features affect tumour progression. We identified GSC morphology as a new layer of tumoral heterogeneity with important consequences on GSC proliferation. Strikingly, we showed that the neurodevelopmental morphoregulator ADD3, is sufficient and necessary for maintaining proper GSC morphology, TTC abundance and cell cycle progression as well as required for cell survival. Remarkably, both the effects on cell morphology and proliferation depend on the stability of actin cytoskeleton. Hence, cell morphology and its regulators play a key role in tumor progression by mediating cell-cell communication. We thus propose that GSC morphological heterogeneity holds the potential to identify new therapeutic targets and diagnostic markers.

cell biology↗