Raúl Torres-Ruiz

Developmental transcriptional programs are increasingly recognized as key drivers of paediatric gliomagenesis. Here, we unexpectedly find that the forebrain‐specific doublesex‐ and mab‐3‐related transcription factor a2 (DMRTA2), despite being highly expressed in H3G34‐mutant diffuse hemispheric glioma (DHG‐H3G34) and implicated in tumour initiation, is not required for the maintenance of established patient‐derived tumour cells. These findings support a stage‐specific framework in which transcriptional dependencies are dynamically rewired during tumour progression in paediatric brain tumours.

Immunotherapy has reshaped melanoma treatment, yet the majority of patients fail to respond or develop resistance. Nerve growth factor receptor (NGFR/p75NTR/CD271) has been linked to melanoma aggressiveness and therapeutic resistance, but the underlying mechanisms remain unclear. Here, we demonstrate that pharmacologic inhibition of NGFR with THX-B significantly reduces distant metastasis and restores sensitivity in immunotherapy-resistant tumors. THX-B treatment also enhances intratumoral CD8⁺ T-cell infiltration. Further, we show that immune-resistant melanomas acquire an invasive, ameboid phenotype characterized by elevated NGFR, PD-L1, and activation of non-muscle myosin light chain 2 (NM II; MLC2). Mechanistically, NGFR regulates RhoA/ROCK-dependent MLC2 phosphorylation and proteasomal stabilization. Analysis of melanoma patient samples reveals that high NGFR expression correlates with reduced progression-free survival following immunotherapy. Moreover, NGFR and phosphorylated MLC2 are consistently enriched at the invasive fronts of primary tumors, metastases, and in immunotherapy-resistant cell lines from melanoma patients. Altogether, these findings identify the NGFR–MLC2 axis as a mediator of invasive immune resistance and support NGFR inhibition as a strategy to enhance immunotherapy efficacy.

Oncogene amplifications fuel some of the most lethal, therapy‑refractory cancers, yet remain clinically untargeted. We report a single‑guide CR

KRAS mutations are responsible for a quarter of all lung adenocarcinomas. However, the molecular mechanisms linking these mutations and their frequent secondary dosage amplification to tumor formation are still not fully understood. While ample evidence supports a crucial role for the MAPK pathway in tumor development, the primary effectors targeted by this pathway remain largely unexplored. Here we identify the transcriptional repressor Capicua (CIC) as a key target inactivated by KRAS/MAPK signaling in lung adenocarcinoma. We show that genetic loss of CIC recapitulates the phenotypic consequences of amplified KRAS signaling. Genetic disruption of CIC suppressed the requirement for Kras allelic imbalances and accelerated the transformation of bronchiolar Club cells. We also demonstrate that restoring CIC repressor activity impaired proliferation of CIC-deficient tumor cells and reverted resistance to MAPK pathway inhibitors. These results highlight the key role of CIC during lung tumor formation and suggest that selective pressure for effective CIC inactivation favors secondary amplification of KRAS/MAPK signaling in tumor cells.

The emergence of CRISPR-Cas systems has transformed nucleic acid detection and manipulation. Cas13, a type VI CRISPR effector, targets RNA with high sensitivity through both cis (target RNA) and trans (collateral RNA) cleavage. This property enables the use of fluorescent reporters for sensitive diagnostics. However, Cas13’s heightened sensitivity also leads to reduced specificity due to its susceptibility to single-nucleotide mismatches, potentially causing off-target effects. To overcome this limitation, we developed the first dual-guide RNA system for Cas13 that enhances mismatch discrimination and improves target specificity. This system employs two distinct RNAs—dcrRNA and dtracrRNA—which hybridise to refine target recognition and activation. In vitro experiments demonstrated robust cis- and trans-RNase activity, indicating efficient and specific cleavage. The system accurately detected SARS-CoV-2 RNA, demonstrating its potential for pathogen diagnostics, and successfully discriminated between KRAS G12D and G12C mutations—clinically relevant single-nucleotide variants in cancer diagnosis. These results highlight the dual-guide Cas13 platform’s potential for precise, rapid, and reliable RNA detection. Overall, this approach represents a significant advance over conventional Cas13 systems, offering improved specificity without compromising sensitivity. Its versatility makes it a promising tool for next-generation molecular diagnostics and precision gene editing applications. GRAPHICAL

Hematopoietic Stem Cells (HSCs) possess the ability to long-term reconstitute all the blood lineages and generate all blood cell types. As such, the in vitro generation of HSCs remains a central goal in regenerative medicine. Despite many efforts and recent advancements in the field, there is still no robust, reproducible and efficient protocol for generating bona-fide HSCs in vitro. This suggests that certain regulatory elements have yet to be uncovered. Here, we present a novel and unbiased approach to identifying endogenous components to specify HSCs from pluripotent stem cells. We performed a genome-wide CRISPR activator screening during mesodermal differentiation from mouse embryonic stem cells (mESCs). Following in vitro differentiation, mesodermal KDR+ precursors were transplanted into primary and secondary immunodeficient NSG mice. This approach led to the identification of seven genes (Spata2, Aass, Dctd, Eif4enif1, Guca1a, Eya2, Net1) that, when activated during mesoderm specification, induce the generation of hematopoietic stem and progenitor cells (HSPCs). These cells are capable of serial engraftment and multilineage output (erythroid, myeloid and T and B lymphoid) in vivo. Single-cell RNA sequencing further revealed that activating these seven genes biases the embryoid bodies towards intraembryonic development, instead of extraembryonic, increasing the number of mesodermal progenitors that can generate HSCs. Our findings underscore the importance of differentiation during the first germ layer specification to generate definitive blood stem cells

There is active crosstalk between tumor cells and the tumor microenvironment during metastatic progression, a process that is significantly affected by obesity, particularly in breast cancer. Here we analyze the impact of a high fat diet (HFD) on metastasis, focusing on the role of platelets in the formation of premetastatic niches (PMNs). We find that a HFD provokes pre-activation of platelets and endothelial cells, promoting the formation of PMNs in the lung. These niches are characterized by increased vascular leakiness, platelet activation and overexpression of fibronectin in both platelets and endothelial cells. A HFD promotes interactions between platelets, tumor cells and endothelial cells within PMNs, enhancing tumor cell homing and metastasis. Importantly, therapeutic interventions like anti-platelet antibody administration or a dietary switch reduce metastatic cell homing and outgrowth. Moreover, blocking fibronectin reduces the interaction of tumor cells with endothelial cells. Importantly, when coagulation parameters prior to neoadjuvant treatment are considered, triple negative breast cancer (TNBC) female patients with reduced Partial Thromboplastin time (aPTT) had a significantly shorter time to relapse. These findings highlight how diet and platelet activation in pre-metastatic niches affect tumor cell homing and metastasis, suggesting potential therapeutic interventions and prognostic markers for TNBC patients.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a 12% survival rate, highlighting the need for novel therapies. c-MYC overexpression, driven by upstream mutations and amplifications, reprograms tumor metabolism and promotes proliferation, migration and metastasis. This study identifies ELOVL6, a fatty acid elongase regulated by c-MYC, as a potential therapeutic target. Using PDAC mouse models and cell lines, we show that c-MYC directly upregulates ELOVL6 during tumor progression. Genetic or chemical inhibition of ELOVL6 reduces proliferation and migration by altering fatty acid composition, affecting membrane rigidity, permeability and pinocytosis. These changes increase Abraxane uptake and show a synergistic effect when combined with ELOVL6 inhibition in vitro. In vivo, ELOVL6 interference significantly suppresses tumor growth and improves Abraxane response, prolonging survival. These findings position ELOVL6 as a promising target for improving PDAC treatment outcomes.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease, marked by a survival rate of only 12%. Consequently, the exploration of novel therapeutic strategies becomes a critical clinical imperative. Among the genetic alterations contributing to PDAC, c-MYC overexpression arises due to upstream mutations, amplifications, and copy number alterations. c-MYC serves as a key regulator in the tumor’s metabolic reprogramming, playing a pivotal role in proliferation, migration, and metastasis. This study delves into the investigation of the role of the elongase ELOVL6 in c-MYC-induced cell transformation and its potential as a therapeutic target in PDAC. Here, we demonstrate that c-MYC regulates lipid elongation to promote cell transformation, offering a new avenue for therapeutic intervention. Initially, we show the direct regulation of ELOVLs expression by c-MYC in various PDAC mouse models and cell lines, elucidating its upregulation during transformation and tumor progression. Genetic or chemical inhibition of ELOVL6 results in decreased proliferation and migration, accompanied by alterations in fatty acid elongation. These changes in fatty acid composition led to modifications in membrane rigidity, permeability, and thickness, which collectively affect micropinocytosis and macropinocytosis. Importantly, we observe an increase in Abraxane uptake and a synergistic effect when combined with ELOVL6 interference in vitro . In vivo validation demonstrates that ELOVL6 inhibition significantly reduces tumor growth and enhances the response to Abraxane, thereby increasing overall survival. Altogether, these results position ELOVL6 as a promising therapeutic target in the treatment of PDAC.

The isolation of circulating tumoral DNA (ctDNA) present in the bloodstream brings about the opportunity to detect genomic aberrations from the tumor of origin. However, the low amounts of ctDNA present in liquid biopsy samples makes the development of highly sensitive techniques necessary to detect targetable mutations for the diagnosis, prognosis, and monitoring of cancer patients. Here, we employ standard genomic DNA (gDNA) and eight liquid biopsy samples from different cancer patients to examine the newly described CRISPR-Cas13a-based technology in the detection of the BRAF p.V600E actionable point mutation and appraise its diagnostic capacity with two PCR-based techniques: quantitative Real-Time PCR (qPCR) and droplet digital PCR (ddPCR). Regardless of its lower specificity compared to the qPCR and ddPCR techniques, the CRISPR-Cas13a-guided complex was able to detect inputs as low as 10 pM. Even though the PCR-based techniques have similar target limits of detection (LoDs), only the ddPCR achieved a 0.1% variant allele frequency (VAF) detection with elevated reproducibility, thus standing out as the most powerful and suitable tool for clinical diagnosis purposes. Our results also demonstrate how the CRISPR-Cas13a can detect low amounts of the target of interest, but its base-pair specificity failed in the detection of actionable point mutations at a low VAF; therefore, the ddPCR is still the most powerful and suitable technique for these purposes.