Biology subjects

Torregrosa-Cortes, G.

Publications and source records attributed to Torregrosa-Cortes, G..

4 recordsLinked to original sources

bioRxiv2025

Retinoic acid coordinates the orderly construction of the mammalian body in the anterior-to-posterior sequence

In vertebrate embryos, anterior structures are formed early during gastrulation, while the posterior body develops subsequently. This temporal anterior-to-posterior developmental sequence is a fundamental aspect of animal development. Recent studies have shown that discrete regulatory modules involving Nodal and Wnt signaling pathways, in conjunction with T-box factors Eomes and Brachyury (Tbxt), underlie the differential specification of anterior and posterior mesoderm. However, the mechanism governing the transition from anterior to posterior mesoderm development remains unclear. Our findings suggest that retinoic acid signaling regulates the anterior-to-posterior developmental transition. Using mouse embryonic stem cell-based gastruloids, we show that the preclusion of retinoic acid signaling drives anterior mesoderm development, whereas the mesoderm specified in the presence of retinoic acid acquires posterior identity. Our observations indicate that retinoic acid signaling modulates the Wnt pathway. We demonstrate that both Eomes and Tbxt are essential for suppressing the posterior fate. The negative regulation of Wnt signaling by these T-box factors is critical, along with the preclusion of retinoic acid signaling, to ensure orderly anterior-posterior developmental progression. We propose that the preclusion of retinoic acid signaling early during gastrulation is crucial to maintain low Wnt signal levels, thereby driving anterior mesoderm specification. Subsequently, the activation of retinoic acid signaling results in high Wnt conditions, facilitating a switch to posterior mesoderm development.

developmental biology↗

bioRxiv2025

Integrated in silico and in vitro approaches identify SNX.2112 as a drug vulnerability in t(7;12) AML stem-like cells

The t(7;12) translocation is a chromosomal rearrangement characteristic of infant Acute Myeloid Leukemia (AML). It arises in utero and results in ectopic overexpression of homeobox gene MNX1. Using a 3-dimensional (3D) model of blood development, we recently showed that t(7;12)-AML originates at the endothelial-to-hematopoietic transition, explaining its characteristic gene expression signature. Herein, we employ that signature to interrogate the transcriptional profiles of hundreds of human cell lines against the GDSC database of drug sensitivities to identify candidate drugs against t(7;12)-AML. We employ a cell line in which we engineered t(7;12) and systematically test the candidate drugs by cell surface phenotype and clonogenic assays. Importantly, we identify HSP90 inhibitor SNX.2112 as a potential therapeutic agent against t(7;12)-AML. SNX.2112 selectively eliminates colony-initiating leukemia progenitors in vitro and decreases MNX1 expression, effects recapitulated by other HSP90 inhibitors. SNX.2112 acts at least partly through destabilisation of STAT5 signalling. Critically, SNX.2112-differential signatures uniquely map to progenitors with hemato-endothelial characteristics in t(7;12)-AML patient blasts, suggesting targeting of leukemia-initiating cells. Combinatorial treatment with chemotherapeutic agents indicates synergy, suggesting SNX.2112 potential as a targeted and cytotoxicity-sparing therapeutic approach. Overall, we successfully use an integrated computational and multi-model experimental approach to identify a drug vulnerability of t(7;12)-AML. Key pointsO_LIClassifier-based in silico drug screening identifies vulnerabilities of t(7;12)-infant leukemia C_LIO_LI2D and 3D models of t(7;12)-leukemia match HSP90 inhibition cellular and molecular responses to candidate leukemia stem cells in t(7;12) patient analysis. C_LI

cancer biology↗

bioRxiv2025

A temporal coordination between Nodal and Wnt signalling governs the emergence of the mammalian body plan

Nodal and Wnt signalling play an important role in the emergence of the mammalian body plan, primarily by orchestrating gastrulation. While the literature suggests they cooperate to build the primitive streak, their individual contributions remain poorly understood. Using gastruloids, we found that Wnt/{beta}-catenin drives a genetic program characteristic of the late primitive streak, promoting the development of posterior body structures in a time and dose-dependent manner. Conversely, Nodal activates a distinct transcriptional module resembling the early streak. By engineering gastruloids with varying levels of Nodal signalling, we demonstrate that a decreasing temporal gradient of Nodal activity is critical for establishing the anterior body, with higher Nodal levels producing more anterior structures in a concentration-dependent manner. Our findings suggest that Nodal and Wnt act antagonistically, initiating distinct developmental modules within the primitive streak. This antagonism is likely the core mechanism driving the early body plan in mammals.

developmental biology↗

bioRxiv2024

Cell-cell communication controls the timing of gastruloid symmetry-breaking

How cell fate decisions coordinate with tissue-scale morphogenesis remains a major challenge in developmental biology. Gastruloids, three-dimensional aggregates of pluripotent stem cells that self-organise and break symmetry via polarised Brachyury/T expression, provide an ideal system to address this question. By generating gastruloids with defined initial proportions of T-expressing cells we show that fate decisions occur collectively, with cell-fate proportions influencing the transition rates. Mechanical measurements reveal differences in surface tension between T-positive and T-negative tissues, consistent with radial cell sorting. Finally, incorporating fate dynamics and mechanics into a computational model recapitulates the sequential symmetry-breaking events observed in vitro. Our findings identify a mechanochemical mechanism underlying axis formation, and demonstrate how multicellular systems can robustly self-organise without external signalling cues.

biophysics↗