Biology subjects

Hu, B.

Publications and source records attributed to Hu, B..

At least 73 records · Page 4Linked to original sources

bioRxiv2025

Metagenomics reveals potential interactions between CPR bacteria and their phages in groundwater ecosystems

Candidate phyla radiation (CPR) is a vast lineage composed of bacteria with ultra-small size, streamlined genomes, notable defects in core metabolic potential and symbiotic lifestyle, which are widely detected in groundwater ecosystems. Increasing attention has focused on the physiological and ecological significance of CPR bacteria, while the potential interactions between CPR bacteria and their phages still need more exploration. Here, we collected 82 groundwater metagenomic datasets and further derived 1,162 phages with the potential to infect 2,439 groundwater CPR metagenome-assembled genomes (MAGs). Notably, the groundwater CPR MAGs were predominantly infected by temperate phages, and the abundance profiles of phage-CPR interactions in groundwater ecosystems supported the Piggybacking the Winner (PtW) hypothesis, suggesting that lysogenic infection was a strategy co-evolved by CPR bacteria and their phages in groundwater ecosystems. Intriguingly, the groundwater CPR phages encoded various auxiliary metabolic genes (AMGs) that might promote symbiotic lifestyle and metabolic potential of host CPR MAGs. These included AMGs associated with concanavalin A-like lectin/glucanases superfamily and O-Antigen nucleotide sugar biosynthesis, which could enhance surface adhesion of host CPR MAGs. Moreover, AMGs related to ABC transport system and P-type transporter could strengthen metabolic exchange and uptake of essential nutrients from surroundings. Additionally, AMGs involved in various metabolic pathways might alleviate metabolic deficiencies in host CPR MAGs. This study elucidated the mechanisms of phage-CPR interactions and the potential roles of phages in modulating the physiology and ecology of CPR bacteria within groundwater ecosystems.

microbiology↗

bioRxiv2025

PLXNB1 and other signaling drives a pathologic astrocyte state contributing to cognitive decline in Alzheimer's Disease

Alzheimers disease (AD) is marked by the coordinated emergence of disease-associated cell states across multiple cell types. Here, we first performed a meta-analysis of single-nucleus transcriptomic (snRNAseq) data from 869 brains of diverse decedents, confirming the critical role of an SLC38A2highSMTNhighCACNA1Dhighastrocyte subset, Astrocyte 10 (Ast10), in AD and aging-related cognitive decline. We then investigated the signaling drivers of Ast10s emergence in the aging brain, focusing on interactions among microglial and astrocytic subsets. Analysis of the snRNAseq data prioritized a set of ligands and receptors that are robustly predictive of Ast10 proportions across participants, and we confirm our predictions in multiple studies. Independent validation with spatial transcriptomics reveals striking colocalization of these prioritized ligands with the Ast10 signature in AD brain tissue, but not with other astrocytic states. Genetic ablation of a top receptor PLXNB1 in murine and human iPSC-derived astrocytes decreased the Ast10 signature, confirming its regulatory role. Finally, we find that Ast10 may contribute to cognitive decline through synaptic loss and is associated with cognitive decline independent of AD. Thus, Ast10 and its regulators are potential points of convergence for multiple neurodegenerative mechanisms and may be promising targets for therapeutic development to preserve cognitive function.

neuroscience↗

bioRxiv2025

Epigenetic priming promotes acquisition of tyrosine kinase inhibitor resistance and oncogene amplification in human lung cancer

In mammalian cells, gene copy number is tightly controlled to maintain gene expression and genome stability. However, a common molecular feature across cancer types is oncogene amplification, which promotes cancer progression by drastically increasing the copy number and expression of tumor-promoting genes. For example, in tyrosine kinase inhibitor (TKI)-resistant lung adenocarcinoma (LUAD), oncogene amplification occurs in over 40% of patients tumors. Despite the prevalence of oncogene amplification in TKI-resistant tumors, the mechanisms facilitating oncogene amplification are not fully understood. Here, we find that LUADs exhibit a unique chromatin signature demarcated by strong CTCF and cohesin deposition in drug-naive tumors, which correlates with the boundaries of oncogene amplicons in TKI-resistant LUAD cells. We identified a global chromatin priming effect during the acquisition of TKI resistance, marked by a dynamic increase of H3K27Ac, cohesin loading, and inter-TAD interactions, which occurs before the onset of oncogene amplification. Furthermore, we have found that the METTL7A protein, which was previously reported to localize to the endoplasmic reticulum and inner nuclear membrane, has a novel chromatin regulatory function by binding to amplified loci and regulating cohesin recruitment and inter-TAD interactions. Surprisingly, we discovered that METTL7A remodels the chromatin landscape prior to large-scale copy number gains. Furthermore, while METTL7A depletion has little effect on the chromatin structure and proliferation of drug-naive cells, METTL7A depletion prevents the formation and maintenance of TKI resistant-clones, highlighting the specific role of METTL7A as cells are becoming resistant. In summary, we discovered an unexpected mechanism required for the acquisition of TKI resistance regulated by a largely uncharacterized factor, METTL7A. This discovery sheds light into the maintenance of oncogene copy number and paves the way to the development of new therapeutics for preventing TKI resistance in LUAD.

genetics↗

bioRxiv2025

Genetically Defined Organoid Models Reveal Mechanisms Driving Squamous Cell Neoplastic Evolution and Identify Potential Therapeutic Vulnerabilities

Upper aerodigestive squamous cell carcinoma (UASCC) is an aggressive and lethal neoplasm, with its early neoplastic transformation mechanisms remaining poorly understood. Here, we characterize over 25 genetically-defined organoid models derived from murine and human oral/esophageal tissues harboring key driver mutations. Double knockout of TP53 and CDKN2A induced morphological dysplasia, hyperproliferation, loss of squamous differentiation, and tumorigenicity, which were further exacerbated by additional driver mutations (e.g., PIK3CA, NOTCH1, KMT2C). Single-cell analysis revealed an expansion of quiescent basal cells and proliferative squamous cells, alongside a loss of differentiated squamous cells during malignant transformation. A distinct senescence program, regulated by ANXA1, was markedly diminished during early neoplastic evolution. Mechanistically, the ANXA1-SMAD3-p27KIP1 pathway was identified as a critical regulator of this senescence program, acting to suppress neoplastic features in organoid models. Lastly, our high-throughput, single-organoid-resolution drug screens unexpectedly revealed PIK3CA-driven organoids exhibited sensitivity to Mitomycin C and Onalespib. This study provides novel mechanistic insights into early neoplastic evolution and underscores the value of genetically-defined organoid models for investigating cancer biology and identifying targeted therapies.

cancer biology↗

bioRxiv2024

Deciphering the thiolactonization mechanism in thiolactomycin biosynthesis

Thiolactomycin (1), which features a unique{gamma} -thiolactone ring, is a promising antibiotic candidate that specifically targets bacterial type II fatty acid synthase. Despite extensive studies on its pharmacological activities, modes of action, and chemical synthesis, the enzymatic processes responsible for forming the activity-determining{gamma} -thiolactone ring have remained largely unknown. Here, we resolve this problem by revealing that the condensation and heterocyclization (Cy) domain of the nonribosomal peptide synthetase (NRPS) TlnC (TlnCCy), along with the cytochrome P450 enzyme TlnA, cooperatively enable the{gamma} -thiolactone assembly. TlnCCy mediates an unusual sulfurtransfer reaction to sulfurate the polyketide intermediate, generating a thiocarboxylate intermediate. Subsequently, TlnA acts as a{gamma} -thiolactone synthase, converting the linear thiocarboxylate intermediate into 1 via a distal radical-based cyclization mechanism. These findings not only expand the functional and catalytic repertoires of NRPS Cy domains and P450 enzymes, but also highlight a special enzymatic strategy for{gamma} -thiolactone biosynthesis in nature. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/629141v2_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@7e0ad2org.highwire.dtl.DTLVardef@f86b80org.highwire.dtl.DTLVardef@159d136org.highwire.dtl.DTLVardef@1b633ff_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2024

Representational learning by optimization of neural manifolds in an olfactory memory network

Cognitive brain functions rely on experience-dependent internal representations of relevant information. Such representations are organized by attractor dynamics or other mechanisms that constrain population activity onto "neural manifolds". Quantitative analyses of representational manifolds are complicated by their potentially complex geometry, particularly in the absence of attractor states. Here we trained juvenile and adult zebrafish in an odor discrimination task and measured neuronal population activity to analyze representations of behaviorally relevant odors in telencephalic area pDp, the homolog of piriform cortex. No obvious signatures of attractor dynamics were detected. However, olfactory discrimination training selectively enhanced the separation of neural manifolds representing task-relevant odors from other representations, consistent with predictions of autoassociative network models endowed with precise synaptic balance. Analytical approaches using the framework of manifold capacity revealed multiple geometrical modifications of representational manifolds that supported the classification of task-relevant sensory information. Manifold capacity predicted odor discrimination across individuals better than other descriptors of population activity, indicating a close link between manifold geometry and behavior. Hence, pDp and possibly related recurrent networks store information in the geometry of representational manifolds, resulting in joint sensory and semantic maps that may support distributed learning processes.

neuroscience↗

bioRxiv2024

ChIPbinner: An R package for analyzing broad histone marks binned in uniform windows from ChIP-Seq or CUT&RUN/TAG data

BackgroundThe decreasing costs of sequencing, along with the growing understanding of epigenetic mechanisms driving diseases, have led to the increased application of chromatin immunoprecipitation (ChIP-Seq), Cleavage Under Targets & Release Using Nuclease (CUT&RUN) and Cleavage Under Targets and Tagmentation (CUT&TAG) sequencing - which are designed to map DNA or chromatin-binding proteins to their genome targets - in biomedical research. Existing software tools, namely peak-callers, are available for analyzing data from these technologies, although they often struggle with diffuse and broad signals, such as those associated with broad histone post-translational modifications (PTMs). ResultsTo address this limitation, we present ChIPbinner, an open-source R package tailored for reference-agnostic analysis of broad PTMs. Instead of relying on pre-identified enriched regions from peak-callers, ChIPbinner divides (bins) the genome into uniform windows. Thus, users are provided with an unbiased method to explore genome-wide differences between two samples using scatterplots, principal component analysis (PCA), and correlation plots. It also facilitates the identification and characterization of differential clusters of bins, allowing users to focus on specific genomic regions significantly affected by treatments or mutations. We demonstrated the effectiveness of this tool through a case study assessing H3K36me2 depletion following NSD1 knockout in head and neck squamous cell carcinoma, highlighting the advantages of ChIPbinner in detecting broad histone mark changes over existing software. ConclusionsBinned analysis provides a more holistic view of the genomic landscape, allowing researchers to uncover broader patterns and correlations that may be missed when solely focusing on individual peaks. ChIPbinner offers researchers a convenient tool to perform binned analysis. It improves on previously published software by providing a clustering approach that is independent of each bins differential enrichment status, while also offering additional features for downstream analysis of these differentially enriched bins.

bioinformatics↗

bioRxiv2024

A Nerve-Fibroblast Axis in Mammalian Lung Fibrosis

Fibrosis contributes to incurable pathologies in vital organs including the lung. Myofibroblasts are fibrogenic effector cells that accumulate via incompletely understood mechanisms. We discovered that 1-adrenoreceptor expressing myofibroblasts receive sympathetic nerve-derived noradrenergic inputs in fibrotic mouse and human lungs. We combined optical clearing, whole lung imaging, cell-specific gene deletion in sympathetic nerves and myofibroblasts, pharmacologic interventions, sympathetic nerve co-culture and precision-cut lung slices, with analysis of bronchoalveolar lavage fluid, lung tissues, single-cell RNA sequencing datasets, and isolated lung fibroblasts from patients with diverse forms of pulmonary fibrosis to characterize a fibrogenic unit comprised of aberrantly patterned sympathetic nerves and 1-adrenoreceptor subtype D expressing myofibroblasts. The discovery of this previously undefined nerve-fibroblast axis that is conserved across species demonstrates the pivotal contribution of nerves to tissue remodeling and heralds a novel paradigm in fibrosis research.

cell biology↗

bioRxiv2024

Development of SacB-based Counterselection for Efficient Allelic Exchange in Fusobacterium nucleatum

Fusobacterium nucleatum, prevalent in the oral cavity, is significantly linked to overall human health. Our molecular comprehension of its role in oral biofilm formation and its interactions with the host under various pathological circumstances has seen considerable advancements in recent years, primarily due to the development of various genetic tools for DNA manipulation in this bacterium. Of these, counterselection-based unmarked in-frame mutation methods have proved notably effective. Under suitable growth conditions, cells carrying a counterselectable gene die, enabling efficient selection of rare defined allelic exchange mutants. The sacB gene from Bacillus subtilis, encoding levansucrase, is a widely used counterselective marker partly due to the easy availability of sucrose. Yet, its potential application in F. nucleatum genetic study remains untested. We demonstrated that F. nucleatum cells expressing sacB in either a shuttle or suicide plasmid exhibit a lethal sensitivity to supplemental sucrose. Utilizing sucrose counterselection, we created an in-frame deletion of the F. nucleatum tonB gene, a critical gene for energy-dependent transport processes in Gram-negative bacteria, and a precise knockin of the luciferase gene immediately following the stop codon of the hslO gene, the last gene of a five-gene operon possible related to the natural competence of F. nucleatum. Post counterselection with 5% sucrose, chromosomal plasmid loss occurred in all colonies, leading to gene alternations in half of the screened isolates. This sacB-based counterselection technique provides a reliable method for isolating unmarked gene mutations in wild-type F. nucleatum, enriching the toolkit for fusobacterial research. IMPORTANCEInvestigations into Fusobacterium nucleatums role in related diseases significantly benefit from the strategies of creating unmarked gene mutations, which hinge on using a counterselective marker. Previously, the galk-based allelic exchange method, while effective, faced an inherent limitation - the need for a modified host. This study aims to surmount this limitation by substituting galK with sacB for gene modification in F. nucleatum. Our application of the sacB-based methodology successfully yielded a tonB in-frame deletion mutant and a luciferase gene knockin at the precise chromosomal location in the wild-type background. The new method augments the existing toolkit for F. nucleatum research and has far-reaching implications due to the easy accessibility to the counterselection compound sucrose. We anticipate its broader adoption in further exploration, thereby reinforcing its critical role in propelling our understanding of F. nucleatum.

microbiology↗

bioRxiv2024

Seq2Topt: a sequence-based deep learning predictor of enzyme optimal temperature

An accurate deep learning predictor is needed for enzyme optimal temperature (Topt), which quantitatively describes how temperature affects the enzyme catalytic activity. Seq2Topt, developed in this study, reached a superior accuracy on Topt prediction just using protein sequences (RMSE = 13.3 and R2=0.48) in comparison with existing models, and could capture key protein regions for enzyme Topt with multi-head attention on residues. Through case studies on thermophilic enzyme selection and predicting enzyme Topt shifts caused by point mutations, Seq2Topt was demonstrated as a promising computational tool for enzyme mining and in-silico enzyme design. Additionally, accurate deep learning predictors of enzyme optimal pH (Seq2pHopt, RMSE=0.92 and R2=0.37) and melting temperature (Seq2Tm, RMSE=7.57 and R2=0.64) were developed based on the model architecture of Seq2Topt, suggesting that the development of Seq2Topt could potentially give rise to a useful prediction platform of enzymes.

bioinformatics↗

bioRxiv2024

Video Foundation Models for Animal Behavior Analysis

Computational approaches leveraging computer vision and machine learning have transformed the quantification of animal behavior from video. However, existing methods often rely on task-specific features or models, which struggle to generalize across diverse datasets and tasks. Recent advances in machine learning, particularly the emergence of vision foundation models, i.e., large-scale models pre-trained on massive, diverse visual repositories, offers a way to tackle these challenges. Here, we investigate the potential of frozen video foundation models across a range of behavior analysis tasks, including classification, retrieval, and localization. We use a single, frozen model to extract general-purpose representations from video data, and perform extensive evaluations on diverse open-sourced animal behavior datasets. Our results demonstrate that features with minimal adaptation from foundation models achieve competitive performance compared to existing methods specifically designed for each dataset, across species, behaviors, and experimental contexts. This highlights the potential of frozen video foundation models as a powerful and accessible backbone for automated behavior analysis, with the ability to accelerate research across diverse fields from neuroscience, to ethology, and to ecology.

animal behavior and cognition↗

bioRxiv2024

Aging trajectories of memory CD8+ T cells differ by their antigen specificity

Memory T cells are a highly dynamic and heterogeneous population that is maintained by cytokine-driven homeostatic proliferation interspersed with episodes of antigen-mediated expansion and contraction which affect their functional state and their durability. This heterogeneity complicates studies on the impact of aging on global human memory cells, specifically, it is unclear how aging drives memory T cell dysfunction. Here, we used chronic infection with Epstein-Barr virus (EBV) to assess the influence of age on memory states at the level of antigen-specific CD8+ T cells. We find that in young adults (<40 years), EBV-specific CD8+ T cells assume preferred differentiation states depending on their peptide specificity. By age >65-years, different T cell specificities had undergone largely distinct aging trajectories, which had in common a loss in adaptive and a gain in innate immunity signatures. No evidence was seen for cellular senescence or exhaustion. While naive/stem-like EBV-specific T cells disappeared with age, T cell diversity of EBV-specific memory cells did not change or even increased. In summary, by controlling for antigen specificity we uncover age-associated shifts in gene expression and TCR diversity that have implications for optimizing vaccination strategies and adoptive T cell therapy.

immunology↗

bioRxiv2024

Parvalbumin interneuron ErbB4 controls ongoing network oscillations and olfactory behaviors in mice

Parvalbumin (PV)-positive interneurons modulate the processing of odour information. However, little is known about how PV interneurons dynamically remodel neural circuit responses in the olfactory bulb (OB) and their physiological significance. This study showed that a reinforced odour-discrimination task upregulated ErbB4 kinase activity in the mouse OB. ErbB4 knockout in the OB impaired the dishabituation of odour responses and discrimination of complex odours, whereas odour memory or adaptation was not altered in mice. ErbB4-positive neurones were localised throughout the OB, whereas ErbB4 was largely expressed in PV-positive interneurons within the internal and external plexiform layers. Similarly, ErbB4 ablation in PV interneurons disrupted olfactory discrimination and dishabituation in mice. ErbB4 knockout in PV interneurons disrupted the odour-evoked responses of mitral/tufted cells and increased the power of the ongoing local field potential in awake mice. We also observed a decrease in the frequency of miniature inhibitory postsynaptic currents and deficits in stimulus-evoked recurrent and lateral inhibition of mitral cells following PV-ErbB4 loss, suggesting a broad impairment in inhibitory microcircuits. These findings demonstrate that PV-ErbB4 signalling regulates inhibitory microcircuit activity, ongoing oscillations, and OB output, which underlie normal olfactory behaviour.

neuroscience↗

bioRxiv2024

Nuclear FAK aggravates CD8+ T cell exhaustion via the SP1-IL-6 axis in colorectal cancer

Nuclear abnormalities such as nuclear deformation are hallmarks of many diseases, including cancer. Accumulating evidence suggests that the dense and mechanically stiff tumor microenvironment promotes nuclear deformation in cancer cells. However, little is known about how nuclear deformation in neoplastic cells regulates immune exhaustion in the tumor microenvironment. Here, we found that lamin A/C-mediated nuclear stiffening in neoplastic cells promotes the nuclear translocation of phosphorylated focal adhesion kinase (pFAK), which is strongly correlated with the heterogeneity and exhaustion of CD8+ T cells within the spatial context of the tumor microenvironment in human colorectal cancer. Mechanistically, we revealed that increased nuclear tension within tumor cells promotes pFAK nuclear translocation, where nuclear pFAK was found to regulate SP1/IL-6-mediated T-cell exhaustion and the transcription of proinflammatory cytokines/chemokines. Pharmacological inhibition or disruption of pFAK nuclear translocation enhanced antitumor immune responses and synergistically potentiated PD-1 and TIM-3 immunotherapy by increasing CD8+ T-cell cytotoxicity and restoring exhaustion in preclinical models of colorectal cancer. These findings highlight the pivotal role of nuclear tension-mediated pFAK translocation into the tumor cell nucleus in regulating CD8+ T-cell exhaustion, suggesting that pFAK is a promising target for advancing cancer immunotherapy.

immunology↗

bioRxiv2024

MitoStructSeg: A Comprehensive Platform for Mitochondrial Structure Segmentation and Analysis

Mitochondrial morphology and structural changes are closely associated with metabolic dysfunction and disease progression. However, the structural complexity of mitochondria presents a major challenge for accurate segmentation and analysis. Most existing methods focus on delineating entire mitochondria but lack the capability to resolve fine internal features, particularly cristae. In this study, we introduce MitoStructSeg, a deep learning-based framework for mitochondrial structure segmentation and quantitative analysis. The core of MitoStructSeg is AMM-Seg, a novel model that integrates domain adaptation to improve cross-sample generalization, dual-channel feature fusion to enhance structural detail extraction, and continuity learning to preserve spatial coherence. This architecture enables accurate segmentation of both mitochondrial membranes and intricately folded cristae. MitoStructSeg further incorporates a quantitative analysis module that extracts key morphological metrics, including surface area, volume, and cristae density, allowing comprehensive and scalable assessment of mitochondrial morphology. The effectiveness of our approach has been validated on both human myocardial tissue and mouse kidney tissue, demonstrating its robustness in accurately segmenting mitochondria with diverse morphologies. In addition, we provide an open source, user-friendly tool to ensure practical usability.

bioinformatics↗

bioRxiv2024

STAN, a computational framework for inferring spatially informed transcription factor activity across cellular contexts

Transcription factors (TFs) drive significant cellular changes in response to environmental cues and intercellular signaling. Neighboring cells influence TF activity and, consequently, cellular fate and function. Spatial transcriptomics (ST) captures mRNA expression patterns across tissue samples, enabling characterization of the local microenvironment. However, these datasets have not been fully leveraged to systematically estimate TF activity governing cell identity. Here, we present STAN (Spatially informed Transcription factor Activity Network), a linear mixed-effects computational method that predicts spot-specific, spatially informed TF activities by integrating curated TF-target gene priors, mRNA expression, spatial coordinates, and morphological features from corresponding imaging data. We tested STAN using lymph node, breast cancer, and glioblastoma ST datasets to demonstrate its applicability by identifying TFs associated with specific cell types, spatial domains, pathological regions, and ligand-receptor pairs. STAN augments the utility of STs to reveal the intricate interplay between TFs and spatial organization across a spectrum of cellular contexts.

bioinformatics↗

bioRxiv2024

Epidermal Growth Factor Receptor Regulates Beclin-1 in Hyperoxia

While delivery of supplemental oxygen is a life-saving therapy, exposure to high levels of oxygen, called hyperoxia, is associated with increased mortality in the intensive care unit (ICU). Hyperoxia leads to oxidant-mediated acute lung injury (ALI) and pulmonary cell death, called hyperoxic acute lung injury (HALI). Elucidation of molecular mechanisms in HALI could identify therapeutic targets in ALI. In the current study, we examined in vivo effects of HALI on Beclin-1 (BCN1), a molecule that regulates autophagy and cell death. Effects of HALI on BCN1 and autophagy markers were examined in wildtype mice. Analysis of BCN1 and autophagy was completed via Western blot, RT-qPCR, and immunohistochemistry. In wildtype mice, HALI led to increased BCN1 in the lung and in the alveolar epithelium. HALI resulted in significant alterations in markers of autophagy in the lung, including reduced microtubule-associated protein 1B-light chain (LC3B)-II/-I ratios, suggesting reduced autophagic flux. HALI caused increased LDH release in human alveolar type-II cells derived from induced pluripotent stem cells (AT2siPSC), as well as reduced LC3B-II/-I ratios. We previously showed that inhibition of the tyrosine kinase receptor epidermal growth factor receptor (EGFR) is protective in HALI. EGFRWa5/+ mice, which have genetically reduced EGFR activity and improved survival in HALI, showed increased total BCN1, reduced phosphorylated-(p-)/total BCN1 ratios, and decreased LC3B-II/-I ratios in the lung in HALI compared with wildtype. Administration of wortmannin, a phosphatidylinositol-3 kinase (PI3K) inhibitor which decreases BCN1-mediated autophagy, led to increased mortality in HALI in wildtype mice. These data support that regulation of BCN1 and autophagy by EGFR is a protective mechanism in HALI, a pathway which warrants further study for its therapeutic potential. KEY MESSAGESHALI is associated with increased mortality in the ICU and causes alveolar epithelial cell death, but the role of BCN1 in HALI is not well defined. This study shows that BCN1, a molecule involved in autophagy and cell death, is regulated by EGFR in HALI in vivo. These results are significant because regulation by BCN1 and autophagy by EGFR is a novel pathway in HALI with therapeutic potential that warrants further study.

cell biology↗

bioRxiv2024

Targeting of SUMOylation leads to cBAF complex stabilization and disruption of the SS18::SSX transcriptome in Synovial Sarcoma

Synovial Sarcoma (SS) is driven by the SS18::SSX fusion oncoprotein. and is ultimately refractory to therapeutic approaches. SS18::SSX alters ATP-dependent chromatin remodeling BAF (mammalian SWI/SNF) complexes, leading to the degradation of canonical (cBAF) complex and amplified presence of an SS18::SSX-containing non-canonical BAF (ncBAF or GBAF) that drives an SS-specific transcription program and tumorigenesis. We demonstrate that SS18::SSX activates the SUMOylation program and SSs are sensitive to the small molecule SAE1/2 inhibitor, TAK-981. Mechanistically, TAK-981 de-SUMOylates the cBAF subunit SMARCE1, stabilizing and restoring cBAF on chromatin, shifting away from SS18::SSX-ncBAF-driven transcription, associated with DNA damage and cell death and resulting in tumor inhibition across both human and mouse SS tumor models. TAK-981 synergized with cytotoxic chemotherapy through increased DNA damage, leading to tumor regression. Targeting the SUMOylation pathway in SS restores cBAF complexes and blocks the SS18::SSX-ncBAF transcriptome, identifying a therapeutic vulnerability in SS, positioning the in-clinic TAK-981 to treat SS.

cancer biology↗