8104baf4-13a1-4a3d-b35c-2863791059ab - samples
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ABSTRACT:
PROVIDER: EGAD00001008445 | EGA |
REPOSITORIES: EGA
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Project description:Recent progress in dissecting molecular mechanisms essential for the survival and propagation of cancer cells triggered rapid development of targeted therapies. Although many of these therapies produce impressive initial responses in tumor suppression, the onset of resistance is practically unavoidable. One of the main approaches for preventing this refractory condition relies on the development of effective combination therapies. Unfortunately, selection of optimal targets for combinatorial treatments is often confounded by limitations in our understanding of tumor biology. Here, we describe an unbiased comprehensive strategy that combines ex-vivo shRNA-based genome wide screening, proteomic profiling using BioID and patient tumor sequencing data analyses to overcome current challenges in identifying the best fit co-targeting agents. Integrating these strategies, we selected EGFR and EPHA2 receptors as molecules of choice for co-targeting in cancer cells, and generated a bispecific fully humanized anti-EGFR/EPHA2 antibody with druggable bioanalytical properties that very effectively suppresses tumor growth compared to its prototype therapeutic anti-EGFR antibody, cetuximab. Despite the overactivation of EGFR signaling in multiple malignancies, the therapeutic applicability of cetuximab is limited due to frequent resistance and could benefit from being used in a combination with another targeted compound. Our analysis indicates that EGFR and EPHA2 expression positively correlate in various cancer types and thus, are available for co-targeting in most tumors. Therefore, our work not only presents an efficient unbiased strategy for selecting optimal targets for combination therapies, but also describes a novel bispecific antibody, which has a high potential for being developed into a new clinically-relevant biologics effective in a broad variety of malignancies.
2023-01-27 | PXD023034 | Pride
Project description:Bispecific anti-EGFR/EPHA2 antibody displays strong tumor-suppressing activity
2023-01-30 | PXD023087 | Pride
Project description:Purpose: Accumulating analyses of pro-oncogenic molecular mechanisms triggered a rapid development of targeted cancer therapies. Although many of these treatments produce impressive initial responses, eventual resistance onset is practically unavoidable. One of the main approaches for preventing this refractory condition relies on the implementation of combination therapies. This includes dual-specificity reagents that affect both of their targets with a high level of selectivity. Unfortunately, selection of target combinations for these treatments is often confounded by limitations in our understanding of tumor biology. Here, we describe and validate a multipronged unbiased strategy for predicting optimal co-targets for bispecific therapeutics. Experimental design: Our strategy integrates ex-vivo genome-wide loss of function screening, BioID interactome profiling and gene expression analysis of patient data to identify the best fit co-targets. Final validation of selected target combinations is done in tumorsphere cultures and xenograft models. Results: Integration of our experimental approaches unambiguously pointed towards EGFR and EPHA2 tyrosine kinase receptors as molecules of choice for co-targeting in multiple tumor types. Following this lead, we generated a human bispecific anti-EGFR/EPHA2 antibody that, as predicted, very effectively suppresses tumor growth, compared to its prototype anti-EGFR therapeutic antibody, cetuximab. Conclusion: Our work not only presents a new bispecific antibody with a high potential for being developed into clinically-relevant biologics, but more importantly, successfully validates a novel unbiased strategy for selecting biologically optimal target combinations. This is of a significant translational relevance, as such multifaceted unbiased approaches are likely to augment the development of effective combination therapies for cancer treatment.
2023-02-23 | GSE171920 | GEO
Project description:Mass spectrometry-based quantitative proteomics profiling of in vivo signaling changes in 41 therapy resistant (osimertinib or EGFR/Met bispecific antibody treament) tumors from four xenograft NSCLC models.
2017-08-28 | PXD006114 | Pride
Project description:Patient-derived organoids (PDOs) have demonstrated predictive value in prospective clinical trials supporting selection of personalized treatments. Because PDOs retain the organization and physiological functions of their source tissue, PDO biobanks could also be an ideal substrate to screen for novel therapeutic interventions.
Here we describe a large-scale functional screen of dual targeting bispecific antibodies (bAbs) on a colorectal cancer (CRC) PDO biobank to target their dependency on cancer stem cells.
A novel drug discovery pipeline was assembled where therapeutic bAb panels generated against WNT and receptor tyrosine kinases (RTK) targets were functionally evaluated by high content imaging to capture the complexity of PDO responses across a wide range of different CRCs and paired normal colonic mucosa samples. Our strategy resulted in a bAb that specifically triggers EGFR degradation in LGR5+ CSCs and that exhibits unique therapeutic properties such as potent growth inhibition of KRAS mutant CRCs, blockade of metastasis initiation in preclinical models and minimal toxicity towards normal LGR5+ colon stem cells.
| EGAS00001004584 | EGA
Project description:Background: EGFRvIII is a mutant form of the epidermal growth factor receptor gene (EGFR) that lacks exons 2-7. The resulting protein does not bind to ligands and is constitutively activated. The expression of EGFRvIII is likely confined to various types of cancer, particularly glioblastomas. Although an anti-EGFRvIII vaccine is of great interest, low-molecular-weight substances are needed to obtain better therapeutic efficacy. Thus, the purpose of this study is to identify low molecular weight substances that can suppress EGFRvIII-dependent transformation. Methods: We constructed a new throughput screening system and searched for substances that decreased cell survival of NIH3T3/EGFRvIII spheres under 3-dimensional (3D)-culture conditions, but retained normal NIH3T3 cell growth under 2D-culture conditions. In vivo activity was examined using a mouse transplantation model, and derivatives were chemically synthesized. Functional characterization of the candidate molecules was investigated using an EGFR kinase assay, immunoprecipitation, western blotting, microarray analysis,quantitative polymerase chain reaction analysis, and measurement of lactate and ATP synthesis. Results: In the course of screening 30,000 substances, a reagent, âErtredin,â was found to inhibit anchorage-independent 3D growth of sphere-forming cells transfected with EGFRvIII cDNA. Ertredin also inhibited sphere formation in cells expressing wild-type EGFR in the presence of EGF. However, it did not affect anchorage-dependent 2D growth of parental NIH3T3 cells. The 3D-growth-inhibitory activity of some derivatives, including those with new structures, was similar to Ertredin. Furthermore, we demonstrated that Ertredin suppressed tumor growth in an allograft transplantation mouse model injected with EGFRvIII- or wild-type EGFR-expressing cells; a clear toxicity to host animals was not observed. Functional characterization of Ertredin in cells expressing EGFRvIII indicated that it stimulated EGFRvIII ubiquitination, suppressed both oxidative phosphorylation and glycolysis under 3D conditions, and promoted cell apoptosis. Conclusion: We developed a high throughput screening method based on anchorage-independent sphere formation induced by EGFRvIII-dependent transformation. In the course of screening, we identified Ertredin, which inhibited anchorage-independent 3D growth and tumor formation in nude mice. Functional analysis suggests that Ertredin suppresses both mitochondrial oxidative phosphorylation and cytosolic glycolysis in addition to promoting EGFRvIII degradation, and stimulates apoptosis in sphere-forming, EGFRvIII-overexpressing cells. Patterns of gene expression in cells treated with Ertredin (sample 2), rotenone (sample 3), and AG1478 (sample 4) were compared with vehicle-control cells (sample 1).
2016-08-01 | E-GEOD-76959 | biostudies-arrayexpress
Project description:CD3-bispecific antibodies represent an important therapeutic strategy in oncology. These molecules work by redirecting cytotoxic T cells to antigen-bearing tumor cells. Although CD3-bispecific antibodies have been developed for several clinical indications, cases of cancer-derived resistance are an emerging limitation to the more generalized application of these molecules. Here, we devised whole-genome CRISPR screens to identify cancer resistance mechanisms to CD3-bispecific antibodies across multiple targets and cancer types. By validating the screen hits, we found that deficiency in IFNγ signaling has a prominent role in cancer resistance. Interestingly, IFNγ functions by stimulating the expression of T cell killing-related molecules in a cell type-specific manner. Additionally, by assessing resistance to the clinical CD3-bispecific antibody flotetuzumab, we identified core fucosylation as a novel and critical pathway to regulate flotetuzumab binding to the CD123 antigen. Disruption of this pathway resulted in significant resistance to flotetuzumab treatment. Moreover, proper fucosylation of CD123 is required for its normal biological functions. In order to treat the resistance associated with fucosylation loss, flotetuzumab in combination with an alternative targeting CD3-bispecific antibody demonstrated superior efficacy. Together, our study reveals multiple mechanisms that can be targeted to enhance the clinical potential of current and future T cell engaging CD3-bispecific antibody therapies.
2020-11-12 | GSE159547 | GEO
Project description:Molecular tether-mediated extracellular targeted protein degradation (ePTD) emerges as a promising drug modality. The existing strategies for ePTD have exploited several membrane degrader proteins. However, the current panel of ePTD degraders clearly needs to be expanded, as a given degrader may present tissue-dependent expression and activity. Based on screening of >50 receptors on endocytic rates and on their tissue distribution, we established a resource of potential endocytic carriers that may mediate effective ePTD. We subsequently introduced an adaptable design to assemble “Selected endocytic carrier-targeting chimera (SecTAC)” based on bispecific antibody constructs. The resultant modular chimeras, by co-opting newly identified degraders, directed efficient internalization of extracellular protein cargoes (or nucleic acids). Importantly, shaped by the availability of the corresponding endocytic carrier, the output of a SecTAC could present cell subset selectivity. We also validated the therapeutic potential of SecTAC agents for targeting several cell membrane proteins in tumor cells and primary T cells. Furthermore, we adapted the platform to establish multi-cargo tethers that triggered simultaneous degradation of two cell surface proteins in primary T cells. Taken together, our SecTAC platform has laid the foundation for development of preclinical drug candidates capable of inducing extracellular and membrane target degradation in desirable population of cells.
2024-04-13 | GSE263462 | GEO
Project description:T-cell-recruiting bispecific antibody therapy has yielded promising results in patients with hematologic malignancies, however, resistance and subsequent relapse remains a major challenge. T-cell exhaustion induced by persistent antigen stimulation or tonic receptor signaling has been reported to compromise outcomes of T-cell based immunotherapies. The impact of continuous exposure to bispecifics on T-cell function, however, remains poorly understood. In relapsed/refractory B-cell precursor acute lymphoblastic leukemia patients, 28-day continuous infusion with the CD19xCD3 bispecific antibody blinatumomab led to declining T-cell function. In an in vitro model system, mimicking 28-day continuous infusion with the half-life-extended CD19xCD3 bispecific AMG 562, we identified hallmark features of exhaustion arising over time. Continuous AMG 562 exposure induced progressive loss of T-cell function (day 7 vs day 28 mean specific lysis: 88.4% vs 8.6%; n = 6; p = .0003). Treatment-free intervals (TFIs), achieved by AMG 562 withdrawal, were identified as powerful strategy for counteracting exhaustion. TFIs induced strong functional reinvigoration of T cells (continuous vs TFI specific lysis on day 14: 34.9% vs 93.4%; ± SEM; n = 6; p < .0001) and transcriptional reprogramming. Furthermore, use of a TFI led to improved T-cell expansion and tumor control in vivo. Our data demonstrate the relevance of T-cell exhaustion in bispecific antibody therapy and highlight that T cells can be functionally and transcriptionally rejuvenated with TFIs. In view of the growing number of bispecific molecules being evaluated in clinical trials, our findings emphasize the need to consider and evaluate TFIs in application schedules to improve clinical outcomes.
2022-07-26 | GSE196463 | GEO