Project description:Transcriptionally active ESR1 fusions promote endocrine therapy (ET)-resistant growth and metastasis of estrogen receptor-alpha positive (ERα+) breast cancer. Currently, there are no targeted treatment options for tumors harboring active fusions because the ESR1 ligand binding domain (LBD) has been replaced with non-drug binding sequences from the 3’ partner gene. A mass spectrometry (MS)-based Kinase Inhibitor Pulldown Assay (KIPA) demonstrated an increase of multiple receptor tyrosine kinases including RET in T47D cells expressing active ESR1 fusions. Integrated proteogenomics defined tumor subsets that could be responsive to RET and CDK4/6 directed therapy from 22 biologically heterogeneous ERα+ patient-derived xenograft (PDX) tumors. Inhibition of RET by repurposing an FDA-approved drug significantly suppressed ESR1 fusion-driven growth of cell, PDX-derived organoid (PDXO) and PDX models. CDK4/6 inhibitor treatment showed similar tumor reductions to RET inhibition. Here, we reveal therapeutic kinase vulnerabilities in ESR1 fusion-driven tumors, which will lay the framework for future clinical trials.
2023-10-24 | PXD033339 | Pride
Project description:Machine Learning Identifies Candidates for Drug Repurposing in Alzheimer's Disease
Project description:Improving the poor prognosis of infant leukemias remains an unmet clinical need. This disease is a prototypical fusion oncoprotein-driven pediatric cancer, with MLL (KMT2A)-fusions present in most cases. Direct targeting of these driving oncoproteins represents a unique therapeutic opportunity. This rationale led us to initiate a drug screening with the aim of discovering drugs that can block MLL-fusion oncoproteins. A screen for inhibition of MLL-fusion proteins was developed that overcomes the traditional limitations of targeting transcription factors. This luciferase reporter-based screen, together with a secondary western blot screen, was used to prioritize compounds. We characterized the lead compound, Disulfiram, based on its efficient ablation of MLL fusion proteins. The consequences of drug-induced MLL-fusion inhibition was confirmed by cell proliferation, colony formation, apoptosis assays, RT-qPCR, in vivo assays, RNA-seq and CHIP-qPCR and CHIP-seq analysis. All statistical tests were two-sided. Drug-induced inhibition of MLL-fusion proteins by Disulfiram resulted in a specific block of colony formation in MLL-rearranged cells in vitro, induced differentiation and impeded leukemia progression in vivo. Mechanistically, Disulfiram abrogates MLL-fusion protein binding to DNA, resulting in epigenetic changes and down-regulation of leukemic programs setup by the MLL-fusion protein. Disulfiram can directly inhibit MLL-fusion proteins and demonstrates antitumor activity both in vitro and in vivo, providing, to our knowledge, the first evidence for a therapy that directly target the initiating oncogenic MLL-fusion protein.
2022-08-01 | GSE203203 | GEO
Project description:A drug repurposing screen identifies decitabine as a direct acting antiviral against HSV-1 that works by lethal mutagenesis
Project description:A Drug Repurposing Screen Identifies Fludarabine Phosphate as a Potential Therapeutic Agent for N-MYC Overexpressing Neuroendocrine Prostate Cancers
Project description:Human respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections in young children, the elderly, and immunocompromised individuals. Prior exposure to RSV affords little protection and many are susceptible to reinfection throughout life. Virally encoded non-structural (NS) protein 1 (NS1) is thought to modulate host responses in the cytosol. Here, we describe the nuclear localization of NS1 during RSV infection and a corresponding nuclear role in modulating host transcription. In support, we show that a significant proportion of NS1 is partitions to the nucleus and that NS1 alone is necessary and sufficient to translocate into the nucleus. NS1 co-localizes with exportin XPO1 and inhibition of XPO1 results in NS1 accumulation in the nucleus. Furthermore, nuclear NS1 is chromatin-associated and co-immunoprecipitates with Mediator complex proteins. Chromatin-immunoprecipitation demonstrates enrichment of NS1 binding overlapping Mediator and interferon-stimulated transcription factor binding sites that lie within regulatory elements of genes differentially expressed during RSV infection. Mutation of the unique alpha helix in NS1 enhances its repressive effect on host gene expression. Together, these data suggest that nuclear NS1 may alter host responses to RSV infection by binding at the promoters and enhancers of host immune response genes and disrupting host transcriptional regulators. Our study identifies yet another regulatory layer of interactions with RSV proteins that shapes host response to RSV and potentially impacts long-term immunity to RSV.