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Durinck, K.

Publications and source records attributed to Durinck, K..

13 recordsLinked to original sources

PERTURBATION OF THE AMINO ACID STRESS RESPONSE PATHWAY EXPOSES A METABOLIC VULNERABILITY IN MULTIPLE AGGRESSIVE CANCER SUBTYPES

Cancer cells frequently experience nutrient limitation and depend on adaptive stress-response pathways to maintain metabolic homeostasis. Here, we show that pharmacological perturbation of amino acid stress signaling exerts broad anti-tumor activity across multiple aggressive malignancies, including acute lymphoblastic leukemia, acute myeloid leukemia, triple-negative breast cancer, ovarian cancer, and neuroblastoma. Sensitivity to pathway modulation is associated with a chronic stress-adapted metabolic state marked by constitutive amino acid response signaling, elevated NFE2L2 expression, and reduced mitochondrial abundance despite evidence of efficient oxidative metabolism. Mechanistically, we demonstrate that the ATP-competitive compound GCN2-IN-6 does not phenocopy genetic GCN2 suppression and exhibits context-dependent effects on the amino acid stress response. Nevertheless, tumors experiencing chronic metabolic stress remain exquisitely sensitive to disruption of this adaptive network, regardless of whether signaling is perturbed through canonical inhibition or paradoxical activation. Collectively, our findings identify chronic metabolic stress adaptation as an actionable vulnerability and establish off-balancing amino acid stress signaling as a therapeutic strategy across multiple cancer types

cancer biology↗

SOX11 stimulates γδ T-cell differentiation and synergizes with LMO2 and MYCN to drive γδ-like T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous hematologic malignancy in which LMO2 {gamma}{delta}-like T-ALL represents a rare but clinically aggressive subtype associated with poor treatment response and inferior survival. Integrated transcriptomic analyses identified high SOX11 expression as a defining feature of high-risk LMO2 {gamma}{delta}-like T-ALL, where elevated SOX11 levels correlated with refractory disease and poor clinical outcome. To investigate the functional role of SOX11 in {gamma}{delta} T-cell biology and leukemogenesis, we generated a conditional R26-SOX11 mouse model enabling lineage-specific SOX11 overexpression in T-cell progenitors. SOX11 expression promoted expansion of the innate {gamma}{delta} T-cell compartment in thymus, spleen, and bone marrow, accompanied by transcriptional activation of {gamma}{delta} T-cell differentiation, activation, and cytotoxicity programs. However, SOX11 overexpression alone was insufficient to induce leukemia or confer thymocyte self-renewal capacity. In contrast, combined SOX11 and LMO2 overexpression markedly accelerated T-ALL development and strongly increased the incidence of {gamma}{delta}-like leukemias, thereby recapitulating the human high-risk LMO2 {gamma}{delta}-like T-ALL subtype. Mechanistically, SOX11 expanded the pre-leukemic DN3 thymocyte compartment in LMO2-driven mouse model while promoting differentiation toward the {gamma}{delta} lineage. Transcriptomic profiling identified activation of MYCN-associated transcriptional programs in SOX11/LMO2 pre-leukemic thymocytes. Consistently, MYCN was highly expressed in human LMO2 {gamma}{delta}-like T-ALL, and recurrent stabilizing MYCN P44L mutations were enriched in this subtype. Functional validation using genetic and transplantation-based mouse models demonstrated that SOX11 cooperates with MYCN to accelerate T-ALL onset. Together, these findings establish a cooperative SOX11-MYCN oncogenic axis driving {gamma}{delta}-like T-ALL and provide a novel preclinical model for investigating therapeutic vulnerabilities in this high-risk leukemia subtype.

cancer biology↗

Converting Lysosomes into Photothermal Organelles Enables Nanoparticle-Free Tumor Ablation via Intracellular Vapor Bubbles

Photothermal nanomaterials enable precise tumor ablation but face limitations in biodistribution, tissue penetration, toxicity, and biodegradability. Here, we present a unique concept for nanoparticle-free photothermal therapy based on the lysosomal entrapment of cationic amphiphilic small molecular dyes for spatially controlled vapor bubble (VB)-mediated tumor cell ablation. This strategy, which exploits a universal biological and physical effect, employs intracellular pH gradients for extensive local dye enrichment in acidified organelles, transforming them into transient endogenous nanosized photothermal reactors for subsequent light activation. Using sunitinib, a clinically approved lysosomotropic anticancer drug, and the commercially available dye LysoTracker Deep Red, lacking intrinsic anticancer activity, we demonstrate pulsed laser-induced VB formation specifically from dye-loaded lysosomes, leading to selective photomechanical disruption of various cancer cell models across 2D cultures, 3D spheroids, patient-derived neuroblastoma tumoroids and tumor fragments from an ovarian carcinoma patient. This approach allows precise, low-fluence and wavelength-tunable cancer tissue ablation without the need for synthetic photoresponsive nanoparticles.

bioengineering↗

Targeting replication stress in neuroblastoma by exploiting the synergistic potential of second generation RRM2 and CHK1 inhibitors

Tumor cells often cope with elevated levels of replication stress (RS) causing increased dependency on ATR-CHK1 signalling. We previously presented RRM2, the regulatory component of the ribonucleotide reductase (RNR) enzyme, as novel dependency in neuroblastoma, in keeping with its role in RS resistance. We identified strong synergism for combined RRM2-CHK1 inhibition using the iron chelator triapine and prexasertib respectively. To obtain direct RNR targeting, we evaluated a novel inhibitor, TAS1553, specifically disrupting the RNR complex in this study. Treatment with TAS1553 impedes cell growth and induces enhanced RS, DNA damage and apoptosis. We demonstrated strong synergism between TAS1553 the CHK1 inhibitors prexasertib and SRA737 in both NB and sarcoma cell lines, underscoring the broad clinical potential of combinatorial RRM2-CHK1 inhibition. Transcriptome profiling demonstrated strong overlap between the different RRM2-CHK1 treatments and revealed differential expression of RNA splicing components, opening new perspectives for combination treatments using splicing inhibitors. Altogether, this study paves the way for further preclinical testing of second generation RRM2 and CHK1 inhibitors such as TAS1553 and SRA737 in neuroblastoma and sarcomas.

cancer biology↗

RUVBL1 and RUVBL2 are druggable MYCN regulators in neuroblastoma.

High-risk neuroblastoma is characterized by MYCN amplification and high MYCN or MYC gene expression. These patients have a poor prognosis and there is an urgent need for more effective drugs. While strategies to develop inhibitors that directly target the MYC proteins have remained largely unsuccessful, recent preclinical studies have identified ATR, a key protein of the DNA damage response, as a promising alternative therapeutic target. Here we identified a strong RUVBL1 and RUVBL2 signature in transcriptomics data derived from different MYCN-driven mice tumors treated with ATR inhibitors. The RUVBL proteins form a complex with ATPase activity that has broad cellular functions and we demonstrate that pharmacological inhibition of this protein complex results in a strong reduction of MYC signaling, cell cycle arrest, DNA damage and apoptosis. We confirmed the association with MYCN and identified the RUVBL genes as independent prognosticators in human primary neuroblastoma data.

cancer biology↗

5UTR translational inhibition of neuroblastoma dependency factors using the CR-1-31-B rocaglate

Current therapies for neuroblastoma are often ineffective and survivors suffer from severe long-term therapy related side-effects, underscoring the need for identification of novel drugging strategies. We performed an in-depth evaluation of phenotypic and molecular responses following exposure of neuroblastoma cells to the rocaglate CR-1-31-B, scrutinizing its mode-of-action through integrative ribosome footprinting and shotgun proteome profiling. We could show that CR-1-31-B significantly reduces tumor growth in vivo without apparent toxicity. By means of combined ribosome footprinting and transcriptome analysis we uncovered that CR-1-31-B treatment downregulates translation efficiencies of several major neuroblastoma dependencies including MYCN, CCND1 and ALK as well as factors involved in the G2/M checkpoint. Upregulated targets are enriched for oxidative phosphorylation pathway components and DNA repair. At the proteome level, CR-1-31-B imposed downregulation of a FOXM1 driven signature, including the FOXM1 target gene TPX2. We show that neuroblastoma cells are dependent on TPX2 for growth and DNA repair and further demonstrate enhanced CHK1 sensitivity upon TPX2 knockdown. Next, we also observed synergistic effects of CHK1 inhibition with CR-1-31-B. In conclusion, our data support CR-1-31-B as a potent novel therapeutic agent in neuroblastoma, in particular in combination with DNA damage or replication stress inducing agents.

cancer biology↗

The chromatin reader PHF6 at the crossroad of the replication stress and DNA damage responses in neuroblastoma through interaction with RRM2

The PHF6 protein is a presumed chromatin reader implicated in disease through germline loss-of-function mutations causing cognitive disability syndromes and somatic mutations are predominantly observed in acute T-cell leukemia. Previous reports support a role for PHF6 in DNA damage repair, replication fork restart as well as hematopoietic precursor cell self-renewal capacity and lineage commitment. To explore better how PHF6 mediates these functions, we mapped the PHF6 interactome and identified RRM2 as a consistent binding partner across different normal and malignant cell types. Next, PHF6 knockdown imposed increased replicative stress/DNA damage and suggested possible binding of PHF6 to H3K56ac, a marker for nascent DNA at sites of DNA damage repair. Genome-wide mapping of PHF6 chromatin binding indeed revealed overlap with sites of active DNA damage, binding sites of replication fork proteins and functional crosstalk with the neuroblastoma transcription core regulatory circuitry. Altogether, we show a canonical PHF6-RRM2 interaction enabling active transport of RRM2 to genomic sites of PHF6 mediated fork restart and PHF6 localization to H3K56ac at highly transcribed genes facilitating fork restart following replication-transcription conflicts.

cancer biology↗

Automatic end-to-end analysis of high-throughput in vitro cell culture screening by HTSplotter

In biomedical research, high-throughput screening is often applied as it comes with automatization, higher-efficiency, and more and faster results. High-throughput screening experiments encompass drug, drug combination, genetic perturbagen or a combination of genetic and chemical perturbagen screens. These experiments are conducted in real-time assays over time or in an endpoint assay. The data analysis consists of data cleaning and structuring, as well as further data processing and visualisation, which, due to the amount of data, can easily become laborious, time consuming and error-prone. Therefore, several tools have been developed to aid researchers in this process, but these typically focus on specific experimental set-ups and are unable to process data of several time points and genetic-chemical perturbagen screens. To meet these needs, we developed HTSplotter, available as web tool and Python module, which performs automatic data analysis and visualisation of either endpoint or real-time assays from different high-throughput screening experiments: drug, drug combination, genetic perturbagen and genetic-chemical perturbagen screens. HTSplotter implements an algorithm based on conditional statements in order to identify experiment type and controls. After appropriate data normalization, including growth rate normalization, HTSplotter executes downstream analyses such as dose-response relationship and drug synergism assessment by the Bliss independence (BI), Zero Interaction Potency (ZIP) and Highest Single Agent (HAS) methods. All results are exported as a text file and plots are saved in a PDF file. The main advantage of HTSplotter over other available tools is the automatic analysis of genetic-chemical perturbagen screens and real-time assays where growth rate and perturbagen effect results are plotted over time. In conclusion, HTSplotter allows for the automatic end-to-end data processing, analysis and visualisation of various high-throughput in vitro cell culture screens, offering major improvements in terms of versatility, efficiency and time over existing tools.

bioinformatics↗

MYCN-induced nucleolar stress drives an early senescence-like transcriptional program in hTERT-immortalized RPE cells

MYCN is an oncogenic driver in neural crest-derived neuroblastoma and medulloblastoma. To better understand the early effects of MYCN activation in a neural-crest lineage context, we profiled the transcriptome of immortalized human retina pigment epithelial cells with inducible MYCN activation. Gene signatures associated with elevated MYC/MYCN activity were induced after 24 h of MYCN activation, which attenuated but sustained at later time points. Unexpectedly, MYCN activation was accompanied by reduced cell growth. Gene set enrichment analysis revealed a senescence-like signature with strong induction of p53 and p21 but in the absence of canonical hallmarks of senescence such as beta-galactosidase positivity, suggesting incomplete cell fate commitment. When scrutinizing the putative drivers of this growth attenuation, differential gene expression analysis identified several regulators of nucleolar stress. This process was also reflected by phenotypic correlates such as cytoplasmic granule accrual and nucleolar coalescence. Hence, we propose that the induction of MYCN congests the translational machinery, causing nucleolar stress and driving cells into a transient pre-senescent state. Our findings shed new light on the early events induced by MYCN activation and may help unravelling which factors are required for cells to tolerate unscheduled MYCN overexpression during early malignant transformation. HighlightsO_LIActivation of MYCN attenuates proliferation in RPE1 cells C_LIO_LIGrowth arrest is associated with an early senescence-like transcriptional signature C_LIO_LITranscriptional and phenotypic evidence of nucleolar stress C_LIO_LICDKN1A upregulation in G2 phase primes cells for faltering in subsequent G1 C_LI

cancer biology↗

RRM2 is a target for synthetic lethal interactions with replication stress checkpoint addiction in high-risk neuroblastoma

Neuroblastoma is a pediatric tumor originating from the sympathetic nervous system responsible for 10-15 percent of all childhood cancer deaths. Half of all neuroblastoma patients present with high-risk disease at diagnosis. Despite intensive multi-modal therapies nearly 50 percent of high-risk cases relapse and die of their disease. In contrast to the overall paucity of mutations, high-risk neuroblastoma nearly invariably present with recurrent somatic segmental chromosome copy number variants. For several focal aberrations (e.g. MYCN and LIN28B amplification), the direct role in tumor formation has been established. However, for recurrent aberrations, such as chromosome 2p and 17q gains, the identification of genes contributing to tumor initiation or progression has been challenging due to the scarcity of small segmental gains or amplifications. In this study, we identified and functionally evaluated the ribonucleotide reductase regulatory subunit 2 (RRM2) as a top-ranked 2p putative co-driver and therapeutic target in high-risk neuroblastoma enforcing replicative stress resistance. In vitro knock down and pharmacological RRM2 inhibition highlight RRM2 dependency in neuroblastoma cells, further supported by the finding that co-overexpression of RRM2 in a d{beta}h-MYCN transgenic zebrafish line increased tumor penetrance with 80% and accelerated tumor formation. Given the critical role of RRM2 in replication fork progression and regulation of RRM2 through ATR/CHK1 signaling, we tested combined RRM2 and ATR/CHK1 small molecule inhibition with triapine and BAY1895344/prexasertib respectively, and observed strong synergism, in particular for combined RRM2 and CHK1 inhibition. Transcriptome analysis following combinatorial drugging revealed HEXIM1 as one of the strongest upregulated genes. Using programmable DNA binding of dCas9 with a promiscuous biotin ligase, RRM2 promotor bound proteins were identified including HEXIM1 and NurRD complex members, supporting a cooperative role for HEXIM1 upregulation together with CHK1 inhibition in further attenuating RRM2 expression levels. We evaluated the impact of combined RRM2/CHK1 inhibition in vivo, with treatment of a murine xenograft model showing rapid and complete tumor regression, without tumor regrowth upon treatment arrest. In conclusion, we identified RRM2 as a novel dependency gene in neuroblastoma and promising target for synergistic drug combinations with small compounds targeting DNA checkpoint regulators.

cancer biology↗

Comprehensive benchmarking of single cell RNA sequencing technologies for characterizing cellular perturbation

Technological advances in transcriptome sequencing of single cells continues to provide an unprecedented view on tissue composition and cellular heterogeneity. While several studies have compared different single cell RNA-seq methods with respect to data quality and their ability to distinguish cell subpopulations, none of these studies investigated the heterogeneity of the cellular transcriptional response upon a chemical perturbation. In this study, we evaluated the transcriptional response of NGP neuroblastoma cells upon nutlin-3 treatment using the C1, ddSeq and Chromium single cell systems. These devices and library preparation methods are representative for the wide variety of platforms, ranging from microfluid chips to droplet-based systems and from full transcript sequencing to 3-prime end sequencing. In parallel, we used bulk RNA-seq for molecular characterization of the transcriptional response. Two complementary metrics to evaluate performance were applied: the first is the number and identity of differentially expressed genes as defined in consensus by two statistical models, and the second is the enrichment analysis of biological signals. Where relevant, to make the data more comparable, we downsampled sequencing library size, selected cell subpopulations based on specific RNA abundance features, or created pseudobulk samples. While the C1 detects the highest number of genes per cell and better resembles bulk RNA-seq, the Chromium identifies most differentially expressed genes, albeit still substantially fewer than bulk RNA-seq. Gene set enrichment analyses reveals that detection of a limited set of the most abundant genes in single cell RNA-seq experiments is sufficient for molecular phenotyping. Finally, single cell RNA-seq reveals a heterogeneous response of NGP neuroblastoma cells upon nutlin-3 treatment, revealing putative late-responder or resistant cells, both undetected in bulk RNA-seq experiments.

molecular biology↗

Recurrent chromosomal imbalances provide selective advantage to human embryonic stem cells under enhanced replicative stress conditions

Human embryonic stem cells (hESCs) and embryonal tumors share a number of common features including a compromised G1/S checkpoint. Consequently, these rapidly dividing hESCs and cancer cells undergo elevated levels of replicative stress which is known to induce genomic instability causing chromosomal imbalances. In this context, it is of interest that long-term in vitro cultured hESCs exhibit a remarkable high incidence of segmental DNA copy number gains, some of which are also highly recurrent in certain malignancies such as 17q gain (17q+). The selective advantage of DNA copy number changes in these cells has been attributed to several underlying processes including enhanced proliferation. We hypothesized that these recurrent chromosomal imbalances become rapidly embedded in the cultured hESCs through a replicative stress driven Darwinian selection process. To this end, we compared the effect of hydroxyurea induced replicative stress versus normal growth conditions in an equally-mixed cell population of isogenic euploid and 17q+ hESCs. We could show that 17q+ hESCs rapidly overtook normal hESCs. Our data suggest that recurrent chromosomal segmental gains provide a proliferative advantage to hESCs under increased replicative stress, a process that may also explain the highly recurrent nature of certain imbalances in cancer.

cancer biology↗

A comprehensive dataset of TLX1 positive ALL-SIL lymphoblasts and primary T-cell acute lymphoblastic leukemias

Most currently available transcriptome data of T-cell acute lymphoblastic leukemia (T-ALL) are based on polyA[+] RNA sequencing methods thus lacking non-polyadenylated transcripts. Here, we present the data of polyA[+] and total RNA sequencing in the context of in vitro TLX1 knockdown in ALL-SIL cells and a primary T-ALL cohort. We extended this dataset with ATAC sequencing and H3K4me1 and H3K4me3 ChIP sequencing data to map putative gene regulatory regions. In this data descriptor, we present a detailed report of how the data were generated and which bioinformatics analyses were performed. Through several technical validations, we showed that our sequencing data are of high quality and that our in vitro TLX1 knockdown was successful. We also validated the quality of the ATAC and ChIP sequencing data and showed that ATAC and H3K4me3 ChIP peaks are enriched at transcription start sites. We believe that this comprehensive set of sequencing data can be reused by others to further unravel the complex biology of T-ALL in general and TLX1 in particular.

molecular biology↗