Publications by authors named "Ana Rita Grosso"

Embryo development is an orchestrated process that relies on tight regulation of gene expression to guide cell differentiation and fate decisions. The Srrm2 splicing factor has recently been implicated in developmental disorders and diseases, but its role in early mammalian development remains unexplored. Here, we show that Srrm2 dosage is critical for maintaining embryonic stem cell pluripotency and cell identity.

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  • Transcription termination is essential for creating proper mRNAs and proteins, but under stress, the transcription process can ignore stop signals, leading to "readthrough" transcripts that extend beyond gene ends.
  • A study examining nearly 3000 human transcriptome profiles revealed that 34% of protein-coding genes produce these readthrough transcripts, especially in regions with less transcription activity, inefficient splicing, and more accessible chromatin.
  • The findings suggest that these additional transcripts may act as "miRNA sponges," highlighting that transcription readthrough is common in both unhealthy and healthy tissues and could play a significant role in regulating cellular functions.
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Colorectal cancer (CRC) is the third most common cancer and the second most deathly worldwide. It is a very heterogeneous disease that can develop via distinct pathways where metastasis is the primary cause of death. Therefore, it is crucial to understand the molecular mechanisms underlying metastasis.

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  • - Colorectal cancer (CRC) exhibits significant genetic diversity influenced by various genomic instability pathways, resulting in differences within tumors and their surrounding environments.
  • - A study of 136 CRC samples revealed that this diversity arises from molecular alterations that occur at different rates, with certain genomic features being better predictors of heterogeneity in tumor subtypes and locations.
  • - The research indicates that higher levels of genetic and microenvironment diversity are linked to a reduced likelihood of metastasis, while certain genetic changes that appear later may promote the spread of cancer cells.
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  • - Glycosylation is crucial for human development and health, providing significant structural diversity through various glycan structures, yet its evolutionary implications and tissue-specific roles remain poorly understood.
  • - This study created a comprehensive catalogue of glycosylation-related genes and identified tissue-specific expression patterns, suggesting a "glycosylation code" linked to tissue identity and age-related disorders.
  • - Findings indicate that in cancer, glycosylation factors are significantly disrupted, affecting the tumor microenvironment and immune responses, highlighting the importance of glycosylation in health and disease.
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Angiogenesis, the process by which endothelial cells (ECs) form new blood vessels from existing ones, is intimately linked to the tissue's metabolic milieu and often occurs at nutrient-deficient sites. However, ECs rely on sufficient metabolic resources to support growth and proliferation. How endothelial nutrient acquisition and usage are regulated is unknown.

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DNA oxidation by ten-eleven translocation (TET) family enzymes is essential for epigenetic reprogramming. The conversion of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) initiates developmental and cell-type-specific transcriptional programs through mechanisms that include changes in the chromatin structure. Here, we show that the presence of 5hmC in the transcribed gene promotes the annealing of the nascent RNA to the template DNA strand, leading to the formation of an R-loop.

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Transcription termination is a critical stage for the production of legitimate mRNAs, and consequently functional proteins. However, the transcription machinery can ignore the stop signs and continue elongating beyond gene boundaries, invading downstream neighboring genes. Such phenomenon, designated transcription readthrough, can trigger the expression of pseudogenes usually silenced or lacking the proper regulatory signals.

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Tight regulation of IL-7Rα expression is essential for normal T-cell development. IL-7Rα gain-of-function mutations are known drivers of T-cell acute lymphoblastic leukemia (T-ALL). Although a subset of patients with T-ALL display high IL7R messenger RNA levels and cases with IL7R gains have been reported, the impact of IL-7Rα overexpression, rather than mutational activation, during leukemogenesis remains unclear.

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  • Endothelial cells (ECs) adjust their metabolism for blood vessel growth, but the mechanisms for their transition to a resting (quiescent) state are not well understood.
  • The study reveals that the metabolite S-2-hydroxyglutarate (S-2HG) is essential for maintaining endothelial quiescence by limiting cell cycle progression and metabolic activity, which is triggered by the transcription factor FOXO1.
  • The production of S-2HG is influenced by branched-chain amino acid breakdown, and its increase leads to reduced endothelial cell proliferation and can cause fewer blood vessels in mice, indicating a specific metabolic switch in ECs.
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  • Cancer immunoediting is the interaction between tumor cells and the immune system, which researchers are studying using a fast zebrafish xenograft model to see how the innate immune system affects cancer growth and clearance.
  • In the study, different cancer cell lines show varying behaviors: some are cleared by the immune system (regressors), while others grow and spread (progressors).
  • Specifically, two colorectal cancer cell lines from the same patient exhibit distinct responses, with one type effectively recruiting immune cells for clearance, whereas the other alters immune cells to support tumor growth, highlighting the complex dynamics of tumor interaction with the immune system.
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Congenital disorders of glycosylation (CDG) are rare diseases with variable phenotypes and severity. Immunological involvement remains a largely uncharted topic in CDG, mainly due to lack of robust data. To better characterize immune-related manifestations' prevalence, relevance, and quality-of-life (QoL) impact, we developed electronic questionnaires targeting (1) CDG patients and (2) the general "healthy" population.

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Mammalian Native Elongating Transcript sequencing (mNET-seq) is a recently developed technique that generates genome-wide profiles of nascent transcripts associated with RNA polymerase II (Pol II) elongation complexes. The ternary transcription complexes formed by Pol II, DNA template and nascent RNA are first isolated, without crosslinking, by immunoprecipitation with antibodies that specifically recognize the different phosphorylation states of the polymerase large subunit C-terminal domain (CTD). The coordinate of the 3' end of the RNA in the complexes is then identified by high-throughput sequencing.

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Intratumor genetic heterogeneity (ITH) is the main obstacle to effective cancer treatment and a major mechanism of drug resistance. It results from the continuous evolution of different clones of a tumor over time. However, the molecular features underlying the emergence of genetically-distinct subclonal cell populations remain elusive.

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The highly intronic nature of protein coding genes in mammals necessitates a co-transcriptional splicing mechanism as revealed by mNET-seq analysis. Immunoprecipitation of MNase-digested chromatin with antibodies against RNA polymerase II (Pol II) shows that active spliceosomes (both snRNA and proteins) are complexed to Pol II S5P CTD during elongation and co-transcriptional splicing. Notably, elongating Pol II-spliceosome complexes form strong interactions with nascent transcripts, resulting in footprints of approximately 60 nucleotides.

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The lifestyle of intracellular pathogens, such as malaria parasites, is intimately connected to that of their host, primarily for nutrient supply. Nutrients act not only as primary sources of energy but also as regulators of gene expression, metabolism and growth, through various signalling networks that enable cells to sense and adapt to varying environmental conditions. Canonical nutrient-sensing pathways are presumed to be absent from the causative agent of malaria, Plasmodium, thus raising the question of whether these parasites can sense and cope with fluctuations in host nutrient levels.

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Genomic instability is frequently caused by nucleic acid structures termed R-loops that are formed during transcription. Despite their harmful potential, mechanisms that sense, signal, and suppress these structures remain elusive. Here, we report that oscillations in transcription dynamics are a major sensor of R-loops.

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The PVT1 lncRNA has recently been involved in tumorigenesis by affecting the protein stability of the MYC proto-oncogene. Both MYC and PVT1 reside in a well-known cancer-risk locus and enhanced levels of their products have been reported in different human cancers. Nonetheless, the extension and relevance of the MYC-PVT1 deregulation in tumorigenesis has not yet been systematically addressed.

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The congeneric freshwater fish Squalius carolitertii and S. torgalensis inhabit different Iberian regions with distinct climates; Atlantic in the North and Mediterranean in the South, respectively. While northern regions present mild temperatures, fish in southern regions often experience harsh temperatures and droughts.

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This article documents the public availability of transcriptomic resources for (i) the stellate sturgeon Acipenser stellatus, (ii) the flowering plant Campanula gentilis and (iii) two endemic Iberian fish, Squalius carolitertii and Squalius torgalensis.

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Background: Gold nanoparticles have been widely employed for biosensing purposes with remarkable efficacy for DNA detection. Amongst the proposed systems, colorimetric strategies based on the remarkable optical properties have provided for simple yet effective sequence discrimination with potential for molecular diagnostics at point of need. These systems may also been used for parallel detection of several targets to provide additional information on diagnostics of pathogens.

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Tumor-infiltrating lymphocytes (TILs) are important prognostic factors in cancer progression and key players in cancer immunotherapy. Although γδ T lymphocytes can target a diversity of tumor cell types, their clinical manipulation is hampered by our limited knowledge of the molecular cues that determine γδ T cell migration toward tumors in vivo. In this study we set out to identify the chemotactic signals that orchestrate tumor infiltration by γδ T cells.

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The immune system relies on the plasticity of its components to produce appropriate responses to frequent environmental challenges. Dendritic cells (DCs) are critical initiators of innate immunity and orchestrate the later and more specific adaptive immunity. The generation of diversity in transcriptional programs is central for effective immune responses.

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Histone H3 of nucleosomes positioned on active genes is trimethylated at Lys36 (H3K36me3) by the SETD2 (also termed KMT3A/SET2 or HYPB) methyltransferase. Previous studies in yeast indicated that H3K36me3 prevents spurious intragenic transcription initiation through recruitment of a histone deacetylase complex, a mechanism that is not conserved in mammals. Here, we report that downregulation of SETD2 in human cells leads to intragenic transcription initiation in at least 11% of active genes.

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