Publications by authors named "Sebastiaan van Heesch"

Non-canonical (i.e., unannotated) open reading frames (ncORFs) have until recently been omitted from reference genome annotations, despite evidence of their translation, limiting their incorporation into biomedical research.

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Thousands of short open reading frames (sORFs) are translated outside of annotated coding sequences. Recent studies have pioneered searching for sORF-encoded microproteins in mass spectrometry (MS)-based proteomics and peptidomics datasets. Here, we assessed literature-reported MS-based identifications of unannotated human proteins.

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Cancer continues to be a major global health challenge, accounting for 10 million deaths annually worldwide. Since the inception of genome-wide cancer sequencing studies 20 years ago, a core set of ~700 oncogenes and tumor suppressor genes has become the basis for cancer research. However, this research has been based largely on an understanding that the human genome encodes ~19 500 protein-coding genes.

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  • Evolutionary changes in RNA translation rates and new genes, including small open reading frames, play a key role in the development of innovations in primates and rodents.
  • This study examined the hearts of four primate species and two rodent species using advanced ribosome and transcriptomic profiling techniques, focusing on adult heart tissues and stem cell-derived heart cells.
  • Findings revealed rapid evolution in the translation efficiency of mitochondrial complexes and identified numerous unique genomic features related to primate heart evolution, highlighting mechanisms that influence cardiac development and potential disease.
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  • Researchers aim to better understand the protein-coding genome due to its importance in human health, while questioning what previous genomic studies may have overlooked regarding non-canonical open reading frames (ncORFs).
  • Over the last ten years, ncORFs have shown potential relevance in human cell types and diseases, but their impact on the human proteome was previously unclear, prompting a collaborative effort to analyze their protein-level evidence.
  • The study found that 25% of analyzed ncORFs contribute to translated proteins, resulting in over 3,000 new peptides from extensive mass spectrometry data, and established an annotation framework and public tools to support ongoing research in this area.
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Identification of immunogenic cancer neoantigens as targets for therapy is challenging. Here, we integrate the whole-genome and long-read transcript sequencing of cancers to identify the collection of neo-open reading frame peptides (NOP) expressed in tumors. We termed this collection of NOPs the tumor framome.

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Human leukocyte antigen (HLA) restriction of conventional T-cell targeting introduces complexity in generating T-cell therapy strategies for patients with cancer with diverse HLA-backgrounds. A subpopulation of atypical, major histocompatibility complex-I related protein 1 (MR1)-restricted T-cells, distinctive from mucosal-associated invariant T-cells (MAITs), was recently identified recognizing currently unidentified MR1-presented cancer-specific metabolites. It is hypothesized that the MC.

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A hallmark of high-risk childhood medulloblastoma is the dysregulation of RNA translation. Currently, it is unknown whether medulloblastoma dysregulates the translation of putatively oncogenic non-canonical open reading frames (ORFs). To address this question, we performed ribosome profiling of 32 medulloblastoma tissues and cell lines and observed widespread non-canonical ORF translation.

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Article Synopsis
  • Ribosome profiling (Ribo-Seq) has revealed thousands of noncanonical open reading frames (ORFs) that might expand the number of human protein-coding sequences (CDSs) by up to 30%, increasing the count from approximately 19,500 to over 26,000.
  • * However, there are significant uncertainties about how many of these noncanonical ORFs actually produce functional proteins, with estimates varying widely from a few thousand to several hundred thousand.
  • * This research gap has left the genomics and proteomics communities excited but also in need of guidance on how to evaluate the coding potential of these noncanonical ORFs.*
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  • - Ribosome profiling (Ribo-seq) has revealed that there may be at least 7,000 non-canonical open reading frames (ORFs) in the human genome that could expand the number of recognized protein-coding sequences by 30% from around 19,500 to over 26,000.
  • - Despite the exciting possibilities for new coding regions, the scientific community faces challenges in verifying how many of these ORFs actually produce proteins, as estimates of their quantity range widely from a few thousand to several hundred thousand.
  • - The article discusses ongoing research on non-canonical ORFs, the use of ribosome profiling and immunopeptidomics to study them, and the need to understand the evidence required to classify
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A hallmark of high-risk childhood medulloblastoma is the dysregulation of RNA translation. Currently, it is unknown whether medulloblastoma dysregulates the translation of putatively oncogenic non-canonical open reading frames. To address this question, we performed ribosome profiling of 32 medulloblastoma tissues and cell lines and observed widespread non-canonical ORF translation.

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Genes and translated open reading frames (ORFs) that emerged de novo from previously non-coding sequences provide species with opportunities for adaptation. When aberrantly activated, some human-specific de novo genes and ORFs have disease-promoting properties-for instance, driving tumour growth. Thousands of putative de novo coding sequences have been described in humans, but we still do not know what fraction of those ORFs has readily acquired a function.

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  • There is ongoing debate about whether naturally occurring ribosome differences result in specialized ribosomes with distinct functions; this study focuses on the ribosomal protein RPL3L found in skeletal muscle and heart tissues.
  • Researchers created a knockout mouse model to investigate the effects of RPL3L depletion, discovering that RPL3 is up-regulated and forms ribosomes in its place, but this does not alter translational efficiency or affinity for specific transcripts.
  • Instead, the absence of RPL3L enhances the interaction between ribosomes and mitochondria in heart cells, leading to increased ATP production, highlighting a more complex role of RPL3L in regulating RPL3 and mitochondrial function rather than just affecting translation.
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  • This study examines the evolutionary roots of over 7,000 newly identified short open reading frames (sORFs) in humans, finding that many are relatively new in evolutionary terms and formed de novo.
  • Researchers discovered 221 previously overlooked sORFs that can generate tiny peptides, smaller than any known human microprotein.
  • Through mass spectrometry and cellular assays, the study links these small peptides to important biological processes like mRNA splicing and translational regulation, shedding light on the role of young proteins in the human proteome.
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Background: Immunotherapy in high-risk neuroblastoma (HR-NBL) does not live up to its full potential due to inadequate (adaptive) immune engagement caused by the extensive immunomodulatory capacity of HR-NBL. We aimed to tackle one of the most notable immunomodulatory processes in neuroblastoma (NBL), absence of major histocompatibility complex class I (MHC-I) surface expression, a process greatly limiting cytotoxic T cell engagement. We and others have previously shown that MHC-I expression can be induced by cytokine-driven immune modulation.

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TP53 nonsense mutations in cancer produce truncated inactive p53 protein. We show that 5-FU metabolite 5-Fluorouridine (FUr) induces full-length p53 in human tumor cells carrying R213X nonsense mutant TP53. Ribosome profiling visualized translational readthrough at the R213X premature stop codon and demonstrated that FUr-induced readthrough is less permissive for canonical stop codon readthrough compared to aminoglycoside G418.

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Glucocorticoids such as dexamethasone (Dex) are widely used to treat both acute and chronic inflammatory conditions. They regulate immune responses by dampening cell-mediated immunity in a glucocorticoid receptor (GR)-dependent manner, by suppressing the expression of pro-inflammatory cytokines and chemokines and by stimulating the expression of anti-inflammatory mediators. Despite its evident clinical benefit, the mechanistic underpinnings of the gene regulatory networks transcriptionally controlled by GR in a context-specific manner remain mysterious.

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The evolutionary conserved Taurine Upregulated Gene 1 (TUG1) is a ubiquitously expressed gene that is one of the highest expressed genes in human and rodent endothelial cells (ECs). We here show that TUG1 expression decreases significantly in aging mouse carotid artery ECs and human ECs in vitro, indicating a potential role in the aging endothelial vasculature system. We therefore investigated if, and how, TUG1 might function in aging ECs, but despite extensive phenotyping found no alterations in basal EC proliferation, apoptosis, barrier function, migration, mitochondrial function, or monocyte adhesion upon TUG1 silencing in vitro.

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  • - The study investigates alternative promoter usage in the context of complex diseases using CAGE sequencing from the left ventricle of hypertensive (SHR) and normotensive (Brown Norway) rat models.
  • - Researchers identified over 26,000 transcription start sites, including 1,970 novel cardiac ones, and discovered 28 genes with alternative promoter usage between the two rat strains.
  • - The findings suggest that changes in promoter usage may be linked to insulin levels and blood pressure, indicating a possible connection between insulin resistance and hypertension in SHR rats.
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RNA-binding proteins (RBPs) can regulate more than a single aspect of RNA metabolism. We searched for such previously undiscovered multifunctionality within a set of 143 RBPs, by defining the predictive value of RBP abundance for the transcription and translation levels of known RBP target genes across 80 human hearts. This led us to newly associate 27 RBPs with cardiac translational regulation in vivo.

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Heterozygous truncating variants in (TTNtv), the gene coding for titin, cause dilated cardiomyopathy (DCM), but the underlying pathomechanisms are unclear and disease management remains uncertain. Truncated titin proteins have not yet been considered as a contributor to disease development. Here, we studied myocardial tissues from nonfailing donor hearts and 113 patients with end-stage DCM for titin expression and identified a TTNtv in 22 patients with DCM (19.

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Background: Little is known about the impact of trans-acting genetic variation on the rates with which proteins are synthesized by ribosomes. Here, we investigate the influence of such distant genetic loci on the efficiency of mRNA translation and define their contribution to the development of complex disease phenotypes within a panel of rat recombinant inbred lines.

Results: We identify several tissue-specific master regulatory hotspots that each control the translation rates of multiple proteins.

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Long noncoding RNAs (lncRNAs) are a heterogenous group of RNAs, which can encode small proteins. The extent to which developmentally regulated lncRNAs are translated and whether the produced microproteins are relevant for human development is unknown. Using a human embryonic stem cell (hESC)-based pancreatic differentiation system, we show that many lncRNAs in direct vicinity of lineage-determining transcription factors (TFs) are dynamically regulated, predominantly cytosolic, and highly translated.

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Background: Fibrosis is a common pathology in many cardiac disorders and is driven by the activation of resident fibroblasts. The global posttranscriptional mechanisms underlying fibroblast-to-myofibroblast conversion in the heart have not been explored.

Methods: Genome-wide changes of RNA transcription and translation during human cardiac fibroblast activation were monitored with RNA sequencing and ribosome profiling.

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