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Carragher, N. O.

Publications and source records attributed to Carragher, N. O..

At least 19 recordsLinked to original sources

SMAD3-driven cell state transitions underpin immunoresistance in bladder cancer

Despite the clinical success of anti-PD-1/PD-L1 immunotherapy in a subset of patients with high-risk bladder cancer (BLCA), most tumors remain refractory to treatment. We hypothesized that immunotherapy resistance is encoded within the intrinsic signaling state of BLCA cells and arises through specific cell-state transitions that precede therapeutic exposure. To test this hypothesis, we applied a cell State Transition Assessment and Regulation (cSTAR) framework to identify key signaling modules and aberrant causal network connections that (i) drive oncogenic progression and acquisition of aggressive phenotypes and (ii) govern BLCA cell susceptibility to T cell-mediated cytotoxicity. cSTAR analysis identified TGF{beta}/SMAD3 signaling as the principal driver of both oncogenic transformation and immunoresistance in BLCA cells. Inhibiting SMAD3 sensitized BLCA cells to PD-1-expressing Jurkat cells and primary human CD4+ T cell-mediated cytotoxicity through suppression of autophagy and activation of multiple cell death pathways. By integrating cell state transition analysis with functional immune co-culture assays, our work demonstrates that tumor cell state transitions control sensitivity to T cell killing, complementing established immune-intrinsic mechanisms of immunotherapy response.

systems biology↗

Phenotypic Screening Identifies Flunarizine as an Inhibitor of Radiotherapy-Induced Astrocyte Reactivity with Therapeutic Potential in Glioblastoma

Radiotherapy is part of the standard-of-care for glioblastoma, yet tumors invariably recur as incurable lesions post-treatment. Recent studies suggest that radiation-induced astrocyte reactivity fosters a tumor-supportive environment, however effective strategies targeting reactive astrocyte phenotypes are lacking. Using a novel image-based assay, we screened over 1,700 small molecule compounds, identifying 29 that inhibit radiation-induced astrocyte reactivity in human astrocytes. Among these, Flunarizine, a calcium-entry blocker approved for migraine treatment, significantly reduced astrocyte reactivity in vitro and in vivo. In a genetically engineered glioblastoma mouse model, combining Flunarizine with radiotherapy markedly improved survival without affecting unirradiated controls, indicating specificity for a radiation-induced phenotype. Mechanistically, Flunarizine inhibited radiation-induced fibrosis in vivo and directly suppressed astrocytic TGF-beta activation in vitro. Notably, Flunarizine treatment had no direct effect on primary glioblastoma cells, emphasizing its microenvironmental specificity. In conclusion, we identified Flunarizine as a promising repurposed compound capable of effectively mitigating radiation-induced astrocyte reactivity and delaying glioblastoma recurrence. This approach offers a viable therapeutic strategy to enhance current glioblastoma treatments. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=195 SRC="FIGDIR/small/664538v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@d4d0d6org.highwire.dtl.DTLVardef@1dac551org.highwire.dtl.DTLVardef@1d071ccorg.highwire.dtl.DTLVardef@1df1a72_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Identification of drug candidates against glioblastoma with machine learning and high-throughput screening of heterogeneous cellular models

Glioblastoma multiforme (GBM) is an aggressive primary brain tumour that presents significant treatment challenges due to its complex pathology and heterogeneity. The lack of validated molecular targets is a major obstacle for discovering new therapeutic candidates, with no new effective GBM therapies delivered to patients in over two decades. Here, we report the identification of compounds that target the GBM stem cell survival phenotype. Our approach employs machine learning (ML) predictors of cell survival trained on high-throughput, image-based, phenotypic screening data for 3,561 compounds, at multiple concentrations, across a panel of six heterogeneous, patient-derived, GBM stem cell lines. We computationally screened more than 12,000 compounds spanning various chemical classes. Experimental validation of ML-identified candidates across the GBM stem cell lines led to the identification of three compounds with activity against the GBM phenotype. Notably, one of our validated hits, the Hsp90 inhibitor XL888, displayed targeted elimination of all six GBM stem cell lines with IC50 in the nanomolar range. The other two compounds, which displayed broad activity across multiple GBM cell lines with distinct cell line sensitivities, offer routes for future personalised medicine campaigns. Our work demonstrates the use of phenotypic screening in tandem with ML can effectively identify therapeutic leads for personalised treatments in highly heterogeneous indications with few known molecular targets.

cancer biology↗

Systematic identification of context-dependent gene essentiality in Glioblastoma: The GBM-CoDE platform

Glioblastoma (GBM) is a heterogeneous and aggressive brain tumour that is invariably fatal despite maximal treatment. Genetic or transcriptomic biomarkers could be used to stratify patients for treatments, however, pairing biomarkers with appropriate therapeutic targets is challenging. Consequently, therapeutics have not yet been optimised for specific GBM patient subsets. Here we integrate genome-wide CRISPR/Cas9 knockout screening and genetic-annotation data for 60 distinct patient-derived, IDHwildtype, adult GBM cell lines, quantifying the essentiality of 15,145 genes. We describe a novel method using Targeted Learning, to estimate the effect size of GBM-relevant biomarkers on context-dependent gene essentiality (GBM-CoDE). We derive multiple target-biomarker pair hypotheses, which we release in an accessible platform to accelerate translation to biomarker-stratified clinical trials. Two of these (WWTR1 with EGFR mutation/amplification, and VRK1 with VRK2 expression suppression) have been validated in GBM, implying that our additional novel findings may be valid. Our method is readily translatable to other cancers of unmet need.

bioinformatics↗

FAK modulates glioblastoma stem cell energetics via actomyosin contractility: regulation of glycolysis and mitochondrial function

Glycolysis and the TCA cycle are reprogrammed in cancer cells to meet bioenergetic and biosynthetic demands, including by engagement with the extracellular matrix (ECM). We show that focal adhesion kinase (FAK), a mediator of integrin-ECM signalling, is driving cellular energetics in a stem cell model of glioblastoma (GBM). FAK gene deletion inhibits both glycolysis and glutamine oxidation, with increased mitochondrial fragmentation and elevated phosphorylation of the mitochondrial protein MTFR1L at S235. Simultaneously, FAK loss causes a mesenchymal to epithelial transition, enhanced acto-myosin contractility as shown by phospho-myosin light chain (p-MLC S19) and impaired cell migration/invasiveness. Rho-kinase (ROCK) inhibitors suppress p-MLC (S19) and restore glutamine oxidation and elongation of mitochondria. Thus, FAK is a key regulator of both glycolysis and glutamine oxidation mediated by acto-myosin contractility that controls both cell and mitochondrial morphology. Moreover, FAK-dependent cellular energetics are coincident properties with GBM stem cell migration, invasiveness and tumour growth in vivo.

cancer biology↗

Drug combinations targeting FAK and MEK overcomes tumour heterogeneity in glioblastoma

Glioblastoma (GBM) is an aggressive brain tumour with limited treatment options and poor prognosis, largely due to its heterogeneity and the involvement of multiple intracellular signalling pathways that contribute to drug resistance. Standard therapies have not significantly improved patient outcomes over the past two decades. While recent advancements in targeted drug combination therapies, such as dabrafenib and trametinib, show promise for certain GBM subgroups, identifying drug combinations effective across the broader GBM population remains a challenge. Integrin-mediated signalling, particularly through Focal Adhesion Kinase (FAK), plays a pivotal role in GBM pathogenesis and invasion, making it a potential therapeutic target [1]. In our study, we utilized a chemogenomic screening approach to identify synergistic drug combinations that target FAK in glioblastoma. We initially employed a CRISPR-engineered GBM model to assess the effects of FAK depletion and discovered that combining FAK inhibitors with MEK inhibitors, particularly trametinib, demonstrated synergistic effects. This potent combination was validated through various 2D & 3D assays, including cell viability/apoptotic assessment, synergistic analysis, cellular imaging, and target engagement assays. The combination also effectively inhibited spheroid growth and invasion across a diverse panel of patient derived GBM stem cells. Molecular mechanisms underlying these effects included suppression of multiple kinase signalling pathways and enhanced apoptosis, elucidated using Reverse Phase Protein Array (RPPA) profiling and western blot validation. In vivo, the combination therapy significantly reduced tumour volume in orthotopic transplantation models. These findings suggest that combining FAK and MEK inhibitors represent a promising therapeutic strategy to overcome the challenges of GBM treatment.

cancer biology↗

Development of a pipeline to evaluate YAP-TEAD inhibitor potential - direct TEAD inhibition represses cancerous growth in a NF2-mutant model of mesothelioma

As the core, tumorigenic downstream effectors of the Hippo signalling pathway, YAP/TAZ and the TEAD family of transcription factors represent attractive targets for drug discovery efforts within cancer research. This is particularly true within the context of pleural mesothelioma, in which there are many recent preclinical developments and clinical trials evaluating the efficacy of TEAD inhibitors. The range of inhibitors have shown great promise, but comparisons of their performances are so far limited. Here we develop a high content pipeline that enables a comparative analysis of currently developed YAP/TAZ-TEAD inhibitors. We take advantage of isogenic cellular models that enable us to examine inhibitor specificity. We identify genetic compensation of the Hippo pathway transcriptional module, with implications for therapeutic targeting, and implement Cell Painting to develop a detailed morphological profiling pipeline that enables further characterisation, quantification, and analysis of off-target effects. Our pipeline is scalable and allows us to establish specificity and comparative potency within cancer relevant assays in a clinically relevant cellular model.

cancer biology↗

Compound screening in primary human airway basal cells identifies Wnt pathway activators as potential pro-regenerative therapies

Regeneration of the airway epithelium restores barrier function and mucociliary clearance following lung injury and infection. Basal cells are tissue-resident airway stem cells that enact regeneration, yet the mechanisms regulating their proliferation and differentiation remain incompletely understood. To identify compounds that promote primary human airway basal cell proliferation, we performed phenotype-based compound screening of 1,429 compounds (from the ENZO and Prestwick Chemical libraries) in 384-well format using primary cells transduced with lentiviral luciferase. 16 pro-proliferative compounds validated in independent donor cell cultures, with several hit compounds activating the Wnt signalling pathway. The effects of compounds on proliferation were further explored in concentration-response, colony formation and 3D organoid assays. Structurally and functionally-related compounds that more potently induced both Wnt activation and basal cell proliferation were investigated. One such compound, 1-azakenpaullone, induced Wnt target gene activation and basal cell proliferation in mice in the absence of tracheal injury. Our results demonstrate the pro-proliferative effect of small-molecule Wnt activators on airway basal cells. These findings contribute to the rationale to develop novel approaches to modulate Wnt signalling during airway epithelial repair. Summary statementIshii, Orr and colleagues perform a high-throughput screen of 1,429 compounds in primary human airway epithelial cells, identifying Wnt activating compounds as promoters of proliferation.

cell biology↗

A targetable PREX2/RAC1/PI3Kβ signalling axis confers resistance to clinically relevant therapeutic approaches in melanoma

Metastatic melanoma remains a major clinical challenge. Large-scale genomic sequencing of melanoma has identified bona fide activating mutations in RAC1, with mutations of its upstream regulator, the RAC-GEF PREX2, also commonly detected. Crucially, RAC1 mutations are associated with resistance to BRAF-targeting therapies. Despite the role of its homologue PREX1 in melanomagenesis, and evidence that some truncating PREX2 mutations drive increased RAC1 activity, no hotspot mutations have been identified, and the impact of PREX2 mutation remains contentious. Here, we use genetically engineered mouse models and patient-derived BRAFV600E-driven melanoma cell lines to dissect the role of PREX2 in melanomagenesis and response to therapy. We show that while PREX2 is dispensable for the initiation and progression of melanoma, its loss confers sensitivity to clinically relevant therapeutics. Importantly, genetic and pharmacological targeting of the RAC1 effector kinase PI3K{beta} phenocopies PREX2 loss, sensitizing our model systems to therapy. Our data reveal a druggable PREX2/RAC1/PI3K{beta} signalling axis in BRAF-mutant melanoma that could be exploited clinically. Statement of SignificanceMetastatic melanoma remains both a clinical problem, and an opportunity for therapeutic benefit. Co-targeting of the MAPK pathway and the PREX2/RAC1/PI3K{beta} has remarkable efficacy and outperforms monotherapy MAPK targeting in vivo.

cancer biology↗

Single-cell morphological tracking of liver cell states to identify small-molecule modulators of liver differentiation

Alternative therapeutic strategies are urgently required to treat liver disease, which is responsible for 2 million deaths anually. By combining Cell Painting, a morphological profiling assay that captures diverse cellular states, with the bi-potent HepaRG(R) liver progenitor cell line, we have developed a high-throughput, single-cell technique, to track liver cell fate and map small-molecule induced changes using a morphological atlas of bi-lineage liver cell differentiation. To our knowledge this is the first-time single-cell trajectory inference has been applied to image-based Cell Painting data and leveraged for drug screening. The overarching goal of this new method is to aid research into understanding liver cell regeneration mechanisms and facilitate the development of cell-based and small-molecule therapies. Using this approach, we have identified a class of small-molecule SRC family kinase inhibitors that promote differentiation of HepaRG(R) single-cells towards the hepatocyte-like lineage and promotes differentiation of primary human hepatic progenitor cells towards a hepatocyte-like phenotype in vitro.

cell biology↗

A cautionary note on the use of N-acetylcysteine as a reactive oxygen species antagonist to assess copper mediated cell death.

A new form of cell death has recently been proposed involving copper-induced cell death, termed cuproptosis. This new form of cell death has been widely studied in relation to a novel class of copper ionophores, including elesclomol and disulfiram. However, the exact mechanism leading to cell death remains contentious. The oldest and mostly widely accepted biological mechanism is that the accumulated intracellular copper leads to excessive build-up of reactive oxygen species and that this is what ultimately leads to cell death. Most of this evidence is largely based on studies using N-acetylcysteine (NAC), an antioxidant, to relieve the oxidative stress and prevent cell death. However, here we have demonstrated using inductively coupled mass-spectrometry, that NAC pretreatment significantly reduces intracellular copper uptake triggered by the ionophores, elesclomol and disulfiram, suggesting that reduction in copper uptake, rather than the antioxidant activity of NAC, is responsible for the diminished cell death. We present further data showing that key mediators of reactive oxygen species are not upregulated in response to elesclomol treatment, and further that sensitivity of cancer cell lines to reactive oxygen species does not correlate with sensitivity to these copper ionophores. Our findings are in line with several recent studies proposing the mechanism of cuproptosis is instead via copper mediated aggregation of proteins, resulting in proteotoxic stress leading to cell death. Overall, it is vital to disseminate this key piece of information regarding NACs activity on copper uptake since new research attributing the effect of NAC on copper ionophore activity to quenching of reactive oxygen species is being published regularly and our studies suggest their conclusions may be misleading.

biochemistry↗

A novel ILK/STAT3 pathway controls plasticity in a neural stem cell model of glioblastoma.

Glioblastomas (GBM) are driven by malignant neural stem-like cells that display extensive heterogeneity and phenotypic plasticity, which drives tumour progression and therapeutic resistance. Here we show that the nodal extracellular matrix-cell adhesion protein integrin-linked kinase (ILK; a pseudokinase), is a key determinant of phenotypic plasticity and the mesenchymal-like, invasive cell state in mouse GBM stem cells. We found that a novel ILK-STAT3 signalling pathway is required for plasticity that enables the transition of GBM stem cells to an astrocyte-like state both in vitro and in vivo. GBM cells genetically depleted of ILK become predominantly stabilised in a transcriptionally-defined progenitor-like state that is characterised by lack of response to differentiation cues and constitutive proliferation. Loss of ILK or interference with STAT3 impairs differentiation potential, reducing phenotypic plasticity of tumour cell populations; additionally, ILK loss causes a mesenchymal- to epithelial-like morphological transition and suppression of malignancy-associated features. Our work defines ILK as a central regulator of multiple GBM phenotypes including phenotypic plasticity and mesenchymal state.

cancer biology↗

Morphological profiling by cell painting in human neural progenitor cells classifies hit compounds in a pilot drug screen for Alzheimer's disease

1Alzheimers disease (AD) accounts for 60-70% of dementia cases. Current treatments are inadequate and there is a need to develop new approaches to AD drug discovery. We chose to develop a cell phenotype-based drug screen centred on the AD-risk gene, SORL1, which encodes the protein SORLA. Increased AD risk has been repeatedly linked to variants in SORL1, particularly those that confer loss of, or decreased, SORLA. This is consistent with the lower SORL1 levels observed in post-mortem brain samples from individuals with AD. Consistent with its role in the endolysosomal pathway, deletion of SORL1 is associated with enlarged endosomes in neural progenitor cells (NPCs) and neurons. We, therefore, hypothesised that multiparametric, image-based phenotyping would identify features characteristic of SORL1 deletion. An automated morphological profiling assay (known as Cell Painting) was adapted to wild-type and SORL1-/- NPCs. This methodology was used to determine the phenotypic response of SORL1-/- NPCs to treatment with compounds from a small FDA/internationally-approved drug library (TargetMol, 330 compounds). We detected distinct phenotypic signatures for SORL1-/- NPCs compared to isogenic wild-type controls. Furthermore, we identified 16 approved drugs that reversed the mutant morphological signatures in NPCs derived from 3 SORL1-/- subclonal iPSC lines. Network pharmacology analysis revealed the 16 compounds belonged to five mechanistic groups: 20S proteasome, aldehyde dehydrogenase, topoisomerase I and II, and DNA synthesis inhibitors. Enrichment analysis confirmed targeting to gene sets associated with these annotated targets, and to pathways/biological processes associated with DNA synthesis/damage/repair, Proteases/proteasome and metabolism._Prediction of novel targets for some compounds revealed enrichment in pathways associated with neural cell function and AD. The findings suggest that image-based phenotyping by morphological profiling distinguishes SORL1-/- NPCs from isogenic wild-type lines, and predicts treatment responses that rescue SORL1-/--associated cellular signatures that are relevant to both SORLA function and AD. Overall, this work suggests that i) a quantitative phenotypic metric can distinguish iPSC-derived SORL1-/- NPCs from isogenic wild-type control and ii) phenotypic screening combined with multiparametric high-content image analysis is a viable option for drug repurposing and discovery in this human neural cell model of Alzheimers disease.

neuroscience↗

High-content profiling reveals a unified model of copper ionophore dependent cell death in oesophageal adenocarcinoma

Background and AimsOesophageal adenocarcinoma (OAC) is of increasing global concern due to increasing incidence, a lack of effective treatments, and poor prognosis. Therapeutic target discovery and clinical trials have been hindered by the heterogeneity of the disease, lack of driver mutations, and the dominance of large-scale genomic rearrangements. In this work we have characterised three potent and selective hit compounds identified in an innovative high-content phenotypic screening assay. The three hits include two approved drugs; elesclomol and disulfiram, and another small molecule compound, ammonium pyrrolidinedithiocarbamate. We uncover their mechanism of action, discover a targetable vulnerability, and gain insight into drug sensitivity for biomarker-based clinical trials in OAC. MethodsElesclomol, disulfiram, and ammonium pyrrolidinedithiocarbamate were systematically characterised across panels of oesophageal cell lines and patient-derived organoids. Drug treated oesophageal cell lines were morphologically profiled using a high-content, imaging platform. Compounds were assessed for efficacy across patient-derived organoids. Metabolomics and transcriptomics were assessed for the identification of oesophageal-cancer specific drug mechanisms and patient stratification hypotheses. ResultsHigh-content profiling revealed that all three compounds were highly selective for OAC over tissue-matched controls. Comparison of gene expression and morphological signatures unveiled a unified mechanism of action involving the accumulation of copper selectively in cancer cells, leading to dysregulation of proteostasis and cancer cell death. Basal omic analyses revealed proteasome and metabolic markers of drug sensitivity, forming the basis for biomarker-based clinical trials in OAC. ConclusionsIntegrated analysis of high-content imaging, transcriptomic and metabolomic data has revealed a new therapeutic mechanism for the treatment of OAC and represents an alternative target-agnostic drug discovery strategy.

cancer biology↗

Multicenter reverse-phase protein array data integration

Among the technologies available for protein biomarker discovery and validation, reverse-phase protein array (RPPA) benefits from unequalled sample throughput. Panels of high-quality antibodies enable the quantification by RPPA of protein abundance and posttranslational modifications in biological specimens with high precision and sensitivity. Incorporation of RPPA technology into clinical and drug development pipelines requires robust assays that generate reproducible results across multiple laboratories. We implemented the first international multicenter pilot study to investigate RPPA workflow variability. We characterized the proteomic responses of a series of breast cancer cells to two cancer drugs. This analysis quantified 86,832 sample spots, representing 108 biological samples, arrayed at three independent RPPA platforms. This unique integrated set of data is publicly available as a resource to the proteomic and cancer research communities to catalyse further analysis and investigation. We anticipate that this dataset will form a reference for the comparison of RPPA workflows and reagents, which can be expanded in the future, and will aid the identification of platform-robust treatment-marker antigens in breast cancer cells. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/458377v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@e2fb2forg.highwire.dtl.DTLVardef@1d8f425org.highwire.dtl.DTLVardef@84dd60org.highwire.dtl.DTLVardef@e1ccf7_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

Pathway profiling of a novel SRC inhibitor, AZD0424, in combination with MEK inhibitors.

A more comprehensive understanding of how cells respond to drug intervention, the likely immediate signalling responses and how resistance may develop within different microenvironments allows us anticipate how cells adapt to targeted therapy enabling more informed prediction of rational drug combinations. The non-receptor tyrosine kinase SRC regulates many cellular signalling processes and pharmacological inhibition has long been a target of drug discovery projects for the treatment of cancer. Here we describe the in vitro and in vivo characterisation of the small molecule SRC inhibitor, AZD0424. We show that AZD0424 potently inhibits the phosphorylation of tyrosine-416 of SRC (IC50 [~] 100 nM) in many cancer cell lines; however inhibition of cell viability, via a G1 cell cycle arrest, was observed only in a sub-set of cancer cell lines in the low (on target) micromolar range. We profiled the changes in intracellular pathway signalling in cancer cells following exposure to AZD0424 and other targeted therapies using Reverse Phase Protein Array analysis. We demonstrate that SRC is activated in response to MEK inhibitor (trametinib or AZD6244)-treatment of KRAS mutant colorectal cell lines (HCT116 and DLD1) and that AZD0424 abrogates this. Cell lines treated with trametinib or AZD6244 in combination with AZD0424 revealed reduction of EGFR, FAK and SRC compensatory activation, and, synergistically inhibits cell viability in vitro. In vivo, trametinib-treatment of mice bearing HCT116 tumours increased phosphorylation of SRC on Tyr416, and when combined with AZD0424, inhibition of tumour growth is greater than trametinib alone. We also demonstrate that drug-induced resistance to trametinib is not re-sensitised by AZD0424 treatment in vitro, likely as a result of multiple compensatory signalling mechanisms; however inhibition of SRC remains an effective way to block invasion of trametinib resistant tumour cells. These data imply that inhibiting SRC may offer a useful addition to MEK inhibitor combination strategies.

cancer biology↗

Optimized chemogenomic library design strategies for precision oncology

Designing a focused compound screening library of bioactive small molecules is a challenging task since many compounds modulate their effects through multiple protein targets with various degrees of potency and selectivity. We describe here several analytic procedures with adjustable cut-off parameters that enable one to design anticancer target-focused compound libraries optimized for library size, cellular activity, biological and chemical diversity and target selectivity. Even though our focus was on designing compound libraries to enable a comprehensive investigation of the target biology of glioblastoma (GBM), the compound collections cover a wide range of protein targets and biological pathways implicated in various types of cancers, making the libraries widely applicable in precision oncology studies. We published the final screening set library, called the Comprehensive anti-Cancer small-Compound Library, or C3L.We hope these general library design principles and the current, widely annotated small molecule libraries will prove useful for the community in various phenotypic screening experiments in GBM and other cancers.

cancer biology↗

High Content Phenotypic Profiling in Oesophageal Adenocarcinoma Identifies Selectively Active Pharmacological Classes of Drugs for Repurposing and Chemical Starting Points for Novel Drug Discovery

Oesophageal adenocarcinoma (OAC) is a highly heterogeneous disease, dominated by large-scale genomic rearrangements and copy number alterations. Such characteristics have hampered conventional target-directed drug discovery and personalized medicine strategies contributing to poor outcomes for patients diagnosed with OAC. We describe the development and application of a phenotypic-led OAC drug discovery platform incorporating image-based, high-content cell profiling and associated image-informatics tools to classify drug mechanism-of-action (MoA). We applied a high-content Cell Painting assay to profile the phenotypic response of 19,555 compounds across a panel of six OAC cell lines representing the genetic heterogeneity of disease, a pre-neoplastic Barretts oesophagus line and a non-transformed squamous oesophageal line. We built an automated phenotypic screening and high-content image analysis pipeline to identify compounds that selectively modified the phenotype of OAC cell lines. We further trained a machine-learning model to predict the MoA of OAC selective compounds using phenotypic fingerprints from a library of reference compounds. We identified a number of phenotypic clusters enriched with similar pharmacological classes e.g. Methotrexate and three other antimetabolites which are highly selective for OAC cell lines. We further identify a small number of hits from our diverse chemical library which show potent and selective activity for OAC cell lines and which do not cluster with the reference library of known MoA, indicating they may be selectively targeting novel oesophageal cancer biology. Our results demonstrate that our OAC phenotypic screening platform can identify existing pharmacological classes and novel compounds with selective activity for OAC cell phenotypes.

cancer biology↗