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Biology subjects

Ferguson, F. M.

Publications and source records attributed to Ferguson, F. M..

7 recordsLinked to original sources

A Degron Decoy System Co-opts Pathological Seeding to Enable Clearance of Multimeric α-Synuclein.

Pathological seeding of protein misfolding is a hallmark of proteinopathies. However therapeutic strategies to clear these aggregates are lacking, impairing both study of their biological importance in disease etiology and progression as well as development of therapeutics. This is due in part to the need to selectively clear oligomerized proteins whilst leaving functional monomers intact, as well as the challenge of developing molecules that act on the full complement of misfolds the protein can adopt throughout the course of disease. In this work, we describe a dopant system consisting of an engineered alpha-synuclein protein construct that rapidly co-aggregates into existing WT alpha-synuclein oligomers, enabling rapid degradation of the entire assembly in the presence of a small molecule trigger. This work provides proof-of-principle for an approach that transforms pathological seeding from a disease-driver into a therapeutic vulnerability, and is potentially applicable to any proteinopathy without requiring a small molecule binder of the pathologic species.

pharmacology and toxicology↗

Development of PROTACs for targeted degradation of oncogenic TRK fusions

Chromosomal translocations leading to the fusion of tropomyosin receptor kinases (TRK) with diverse partner proteins have been identified as oncogenic drivers in many adult and pediatric cancers. While first-generation TRK kinase inhibitors, such as entrectinib and larotrectinib, have shown positive responses in TRK fusion-positive cancers, resistance mutations against these inhibitors in the kinase domain limit their efficacy. Second-generation inhibitors are in clinical evaluation, highlighting a need for novel therapeutic modalities to achieve durable suppression of the oncogenic activity of TRK fusions. Here, we developed heterobifunctional small molecule degraders (PROTACs) to achieve targeted degradation of TRK fusions. By conjugating entrectinib to thalidomide, we identified JWJ-01-378 as a potent and selective CRBN-recruiting degrader of the TPM3-TRKA fusion. JWJ-01-378 induced TPM3-TRKA degradation through the ubiquitin-proteasome system and proteomics analysis confirmed the acute selectivity of JWJ-01-378 for achieving TPM3-TRKA degradation with minimal off-target effects. While JWJ-01-378 was also able to degrade wild-type TRK, it was unable to degrade TRK inhibitor resistant mutants and ALK fusions. Importantly, TPM3-TRKA degradation by JWJ-01-378 suppressed downstream signaling and reduced cancer cell viability, with improved responses compared to heterobifunctional control compounds that cannot degrade TPM3-TRKA. Together, our study expands the toolbox of compounds for evaluating targeted degradation of TRK fusions in cancer. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/660465v1_ufig13.gif" ALT="Figure 13"> View larger version (19K): org.highwire.dtl.DTLVardef@6c78f7org.highwire.dtl.DTLVardef@179dcdeorg.highwire.dtl.DTLVardef@1939988org.highwire.dtl.DTLVardef@144c718_HPS_FORMAT_FIGEXP M_FIG C_FIG JWJ-01-378 recruits cereblon (CRBN) to induce potent and selective degradation of oncogenic TRK fusions, leading to a collapse in downstream signaling and loss of cancer cell viability. Graphical abstract was created using Biorender.com.

cancer biology↗

ZBTB11 Depletion Targets Metabolic Vulnerabilities in K-Ras Inhibitor Resistant PDAC

Over 95% of pancreatic ductal adenocarcinomas (PDAC) harbor oncogenic mutations in K-Ras. Upon treatment with K-Ras inhibitors, PDAC cancer cells undergo metabolic reprogramming towards an oxidative phosphorylation-dependent, drug-resistant state. However, direct inhibition of complex I is poorly tolerated in patients due to on-target induction of peripheral neuropathy. In this work, we develop molecular glue degraders against ZBTB11, a C2H2 zinc finger transcription factor that regulates the nuclear transcription of components of the mitoribosome and electron transport chain. Our ZBTB11 degraders leverage the differences in demand for biogenesis of mitochondrial components between human neurons and rapidly-dividing pancreatic cancer cells, to selectively target the K-Ras inhibitor resistant state in PDAC. Combination treatment of both K-Ras inhibitor-resistant cell lines and multidrug resistant patient-derived organoids resulted in superior anti-cancer activity compared to single agent treatment, while sparing hiPSC-derived neurons. Proteomic and stable isotope tracing studies revealed mitoribosome depletion and impairment of the TCA cycle as key events that mediate this response. Together, this work validates ZBTB11 as a vulnerability in K-Ras inhibitor-resistant PDAC and provides a suite of molecular glue degrader tool compounds to investigate its function.

cancer biology↗

A Biotin Targeting Chimera (BioTAC) System to Map Small Molecule Interactomes in situ

Unbiased chemical biology strategies for direct readout of protein interactome remodelling by small molecules provide advantages over target-focused approaches, including the ability to detect previously unknown targets, and the inclusion of chemical off-compete controls leading to high-confidence identifications. We describe the BioTAC system, a small-molecule guided proximity labelling platform, to rapidly identify both direct and complexed small molecule binding proteins. The BioTAC system overcomes a limitation of current approaches, and supports identification of both inhibitor bound and molecular glue bound complexes.

pharmacology and toxicology↗

The kinase activity of the cancer stem cell marker DCLK1 drives gastric cancer progression by reprogramming the stromal tumor landscape

Gastric cancer (GC) is the 3rd leading cause of cancer mortality worldwide, therefore providing novel diagnostic and treatment options is crucial for at risk groups. The serine/threonine kinase doublecortin-like kinase 1 (DCLK1) is a proposed driver of GC with frequent amplification and somatic missense mutations yet the molecular mechanism how DCLK1 mediates tumorigenesis is poorly understood. We report how DCLK1 expression orchestrates complementary cancer cell intrinsic and extrinsic processes leading to a comprehensive pro-invasive and pro-metastatic reprogramming of cancer cells and tumor stroma in a DCLK1 kinase-dependent manner. Mechanistically, we identify the chemokine CXCL12 as a key promoter of the pro-tumorigenic properties downstream of DCLK1. Importantly, inhibition of the DCLK1 kinase domain reverses the pro-tumorigenic and pro-metastatic phenotype. Together, this study establishes DCLK1 as a promising, targetable master regulator of GC. TeaserDCLK1 is a druggable cancer driver of GC

cancer biology↗

Rapid and direct control of target protein levels with VHL-recruiting dTAG molecules

Chemical biology strategies for directly perturbing protein homeostasis including the degradation tag (dTAG) system provide temporal advantages over genetic approaches and improved selectivity over small molecule inhibitors. We describe dTAGV-1, an exclusively selective VHL-recruiting dTAG molecule, to rapidly degrade FKBP12F36V-tagged proteins. dTAGV-1 overcomes a limitation of previously reported CRBN-recruiting dTAG molecules to degrade recalcitrant oncogenes, supports combination degrader studies and facilitates investigations of protein function in cells and mice.

cancer biology↗

Targeting the PI5P4K lipid kinase family in cancer using novel covalent inhibitors

The PI5P4Ks have been demonstrated to be important for cancer cell proliferation and other diseases. However, the therapeutic potential of targeting these kinases is understudied due to a lack of potent, specific small molecules available. Here we present the discovery and characterization of a novel pan-PI5P4K inhibitor, THZ-P1-2, that covalently targets cysteines on a disordered loop in PI5P4K/{beta}/{gamma}. THZ-P1-2 demonstrates cellular on-target engagement with limited off-targets across the kinome. AML/ALL cell lines were sensitive to THZ-P1-2, consistent with PI5P4Ks reported role in leukemogenesis. THZ-P1-2 causes autophagosome clearance defects and upregulation in TFEB nuclear localization and target genes, disrupting autophagy in a covalent-dependent manner and phenocopying the effects of PI5P4K genetic deletion. Our studies demonstrate that PI5P4Ks are tractable targets, with THZ-P1-2 as a useful tool to further interrogate the therapeutic potential of PI5P4K inhibition and inform drug discovery campaigns for these lipid kinases in cancer metabolism and other autophagy-dependent disorders.

cancer biology↗