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Bleijerveld, O.

Publications and source records attributed to Bleijerveld, O..

5 recordsLinked to original sources

Integrating computational protein structure predictions and genetic dependencies yields an atlas of human multi-protein complexes (AHMPC)

Knowledge of which proteins interact to form functional complexes in cells is essential for understanding molecular mechanisms in biology. Structure prediction methods recently allowed to compute the Human Interactome of likely binary protein interactions. We combine computational predictions with orthogonal functional data from the Dependency Map that estimate the correlation between genetic dependencies and vulnerabilities of the corresponding gene pairs. This revealed groups of proteins that likely form larger complexes. Clustering analysis followed by AlphaFold3 multi-protein complex predictions and AlphaBridge analysis provided the basis to construct and atlas of human multi-protein complexes (AHMPC), currently encompassing 354 high-confidence predicted multi-protein complexes. These include well-known assemblies and new ones - such as a complex involving SYS1, JTB, and ARFRP1 that we validate experimentally, suggesting an unexpected role of JTB in Golgi traficking. To enable the research community to explore the AHMPC and enable further discovery, we cluster all complexes using functional and disease-related embeddings, demonstrate how structured prompts allow validation by large language models (LLMs), and make all structures and analysis available online as an open resource at https://ahmpc.eu/.

biochemistry↗

MHC1-TIP enables single-tube multimodal immunopeptidome profiling and uncovers intratumoral heterogeneity in antigen presentation

Profiling antigens presented on MHC class I molecules on the cell surface is essential to identify candidate antigens for targeted and personalized immunotherapies. However, mass spectrometry-based immunopeptidomics has traditionally been limited by high input requirements, extensive sample manipulation, and expensive reagents. To overcome these challenges, we developed MHC1-TIP: a scalable, single-tube and cost-effective workflow to enable robust MHC-I ligandome recovery from cell lines, patient-derived organoids, and sub-milligram amounts of clinical tissues. Moreover, MHC1-TIP also preserves compatibility with additional omics profiling technologies and we demonstrate its capacity for quantitative and multimodal profiling of the proteome and immunopeptidome from the same sample to enable integrated analyses of protein expression and antigen presentation. Application of MHC1-TIP to primary renal cell carcinoma fragments revealed extensive intratumoral heterogeneity in antigen presentation that was poorly correlated with source protein expression. MHC1-TIP represents a broadly applicable and sensitive approach for low-input, multimodal immunopeptidomics with clinical and translational relevance.

systems biology↗

TRIM33 loss reduces Androgen Receptor transcriptional output and H2BK120 ubiquitination

The Androgen Receptor (AR) is a ligand-dependent transcription factor that drives prostate cancer development and progression. Although, a detailed effect on AR biology has been described for a number of interacting proteins, many AR coregulators remain to be characterized in relation to their distinct impact on AR function. Here, we describe TRIM33 as a conserved AR-interactor across multiple prostate cancer cell lines. We observed that TRIM33 and AR share overall chromatin interaction profiles, in which TRIM33 is involved in downstream responsive transcriptomic output. In contrast to prior reports, we show that TRIM33 does not impact AR protein stability, but instead propose a model in which TRIM33 facilitates maximal AR activity by interfering with H2BK120 ubiquitination levels.

molecular biology↗

Mitochondrial damage triggers therapy-induced senescence

Glioblastoma (GBM) is a fatal brain tumor with a critical need for better therapies. It is known that the PI3K, MAPK, and CDK4/6 signaling pathways are hyper-activated in these tumors; however, previous studies have used very high concentration of inhibitors to assess their importance, with mixed results. Here we developed PMCi, a combination approach that targets all three pathways simultaneously, at clinically-relevant doses. PMCi effectively suppresses GBM cell proliferation in vitro and in vivo, and outperforms monotherapies and dual combinations. PMCi acts by inducing cellular senescence, which is mediated solely by the mitochondria, and, unlike other forms of senescence, is independent of nuclear damage. This phenotype is caused by a reactive oxygen species (ROS)\cGAS-STING\senescence-associated secretory phenotype (SASP) signaling cascade, that acts in a paracrine manner to establish and maintain senescence. Our results demonstrate that mitochondrial damage is sufficient to drive senescence, and that this can be leveraged to target GBM cells.

cell biology↗

An antibiotic that mediates immune destruction of senescent cancer cells

Drugs that eliminate senescent cells, senolytics, can be powerful when combined with pro-senescence cancer therapies. Using a CRISPR/Cas9-based genetic screen, we identify here SLC25A23 as a vulnerability of senescent cancer cells. Suppressing SLC25A23 disrupts cellular calcium homeostasis, impairs oxidative phosphorylation and interferes with redox signaling, leading to death of senescent cells. These effects can be replicated by salinomycin, a cation ionophore antibiotic. Salinomycin prompts a PANoptosis-like cell death in senescent cells, including apoptosis and two forms of immunogenic cell death: necroptosis and pyroptosis. Notably, we observed that salinomycin treatment or SLC25A23 suppression elevates reactive oxygen species, upregulating death receptor 5 via JNK pathway activation. We show that a combination of a DR5 agonistic antibody and salinomycin is a robust senolytic cocktail. We provide evidence that this drug combination provokes a potent NK and CD8+ T cell mediated immune destruction of senescent cancer cells, mediated by the pyroptotic cytokine IL18. SignificanceThe efficacy of multiple cancer drugs is limited by the induction of senescence, which enables cancer cells to evade cell death. We uncover here a new selective vulnerability of senescent cancer cells and we show that this vulnerability can be targeted with a commonly-used antibiotic. We show that a combination of senescence-inducing therapy, combined with this antibiotic causes a highly immunogenic cell death phenotype that further stimulates potent immune destruction of senescent cancer cells.

cancer biology↗